From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Ozone FAQ: Comments Date: 29 Nov 1995 01:07:58 -0500 Lines: 218 Robert Parson's ozone faqs are a valuable reference to the subject. Particularly noteworthy is that his latest update includes the new findings on the rapid degradation of methyl bromide in soil (J. H. Shorter et al, Nature 377, 717, 1995). I offer the following updates and comments (in CAPS). (Please read the introduction to the relevant faq before using or citing the faq extracts that follow.) Forrest M. Mims III Sun Photometer Atmospheric network (SPAN) ozfaq.pt2: Subject: 1.2) How has stratospheric chlorine changed with time? The total amount of chlorine in the stratosphere has increased by a factor of 2.5 since 1975 [Solomon] During this time period the known natural sources have shown no major increases. COMMENTS: AS NOTED ELSEWHERE IN THE FAQ, NATURAL METHYL CHLORIDE MAY ACCOUNT FOR 15-20% OF CHLORINE IN THE STRATOSPHERE. PERHAPS IT HAS NOT INCREASED, BUT THE RESULTS OF MANY INQUIRIES ON THE NET, PHONE CALLS AND A LITERATURE SEARCH SHOW THAT THIS GAS IS APPARENTLY NOT REGULARLY MONITORED IN THE STRATOSPHERE. SINCE A MAJOR SOURCE IS BIOMASS BURNING, WHICH HAS INCREASED SUBSTANTIALLY SINCE 1978, IS IT NOT PREMATURE TO STATE IT HAS NOT INCREASED? Subject: 4.4) Volcanoes put more chlorine into the stratosphere than CFC's. Short Reply: False. Volcanoes account for at most a few percent of the chlorine in the stratosphere. Long reply: This is one of the most persistent myths in this area. As is so often the case, there is a seed of truth at the root of the myth. Volcanic gases are rich in Hydrogen Chloride, HCl. As we have discussed, this gas is very soluble in water and is removed from the troposphere on a time scale of 1-7 days, so we can dismiss quietly simmering volcanoes as a stratospheric source, just as we can neglect sea salt and other natural sources of HCl. COMMENTS: A WORD SEARCH DID NOT FIND MOUNT EREBUS IN THE FAQ (BUT THE END OF THREE PARTS WAS SOMEHOW CUT OFF WHAT I RECEIVED). EREBUS, A VERY UNUSUAL AND PERSISTENTLY ACTIVE VOLCANO, IS A MAJOR SOURCE OF CHLORINE IN ANTARCTICA, WHICH IS NOTED FOR ITS EXCEPTIONALLY DRY ATMOSPHERE. CLEARLY THIS CHLORINE IS NOT REMOVED AS RAPIDLY AS IN WETTER LOCATIONS. THE SUMMIT OF EREBUS IS BELOW THE TROPOPAUSE, AND I AM AWARE OF NO MECHANISM WHICH MIGHT TRANSPORT SOME OF THIS CHLORINE INTO THE STRATOSPHERE. BUT CURRENT OBSERVATIONS HAVE YET TO COMPLETELY RULE OUT A CONTRIBUTION OF EREBUS EMISSIONS TO OZONE DECLINE IN ANTARCTICA. FOR EXAMPLE, PHILIP R. KYLE HAS WRITTEN,"SUCH SPECULATION IS NOT SUPPORTED BY CURRENT OBSERVATIONS MADE AT MOUNT EREBUS, BUT IT IS IMPORTANT THAT THE SCIENTIFIC COMMUNITY NOT DISMISS THE IDEA OUT OF HAND WITHOUT MAKING THE APPROPRIATE SCIENTIFIC OBSERVATIONS AND EVALUATIONS." ("VOLCANOLOGICAL AND ENVIRONMENTAL STUDIES OF MOUNT EREBUS, ANTARCTICA, ANTARCTIC RESEARCH SERIES, VOL. 66, AMERICAN GEOPHYSICAL UNION, 1994, P. xiv.) ozfaq.pt3: Subject: 5.) How far back do antarctic ozone measurements go? ...Today there are several satellites monitoring ozone and other atmospheric gases; the Russian Meteor-3 carries a new TOMS.... COMMENTS: UNFORTUNATELY, METEOR-3/TOMS CEASED FUNCTIONING NEARLY A YEAR AGO (DECEMBER 1994). THIS IS A MAJOR SETBACK TO GLOBAL OZONE MONITORING SINCE TOMS IS BY FAR THE BEST AND MOST ACCURATE SATELLITE OZONE MAPPING INSTRUMENT. ALTHOUGH TOMS CANNOT MEASURE OZONE IN THE LOWER TROPOSPHERE, WHEN A CORRECTION FACTOR IS ADDED ITS MEASUREMENTS ARE WITHIN A FEW PERCENT OF THOSE BY GROUND-BASED INSTRUMENTS, INCLUDING THOSE OF THE SUN PHOTOMETER ATMOSPHERIC NETWORK (SPAN). PRESENT PLANS CALL FOR LAUNCHING AT LEAST ONE NEW TOMS IN 1995. ONE IS SCHEDULED AS AN EARTH PROBE AND THE OTHER FOR A JAPANESE SATELLITE. THE TOMS OZONE PROCESSING TEAM AT NASA'S GODDARD SPACE FLIGHT CENTER HAS USED THE TIME WITHOUT AN ACTIVE TOMS TO REFINE THE ALGORITHM THAT CALCULATES OZONE FROM TOMS MEASUREMENTS OF BACKSCATTERED UV-B. THE NEW DATA SET, WHICH IS CALLED VERSION 7, IS SCHEDULED FOR RELEASE SOON. IN A TIME WHEN GOVERNMENT SCIENCE BUDGETS ARE UNDER CAREFUL AND APPROPRIATE REVIEW BY THE CONGRESS, IT IS INTERESTING TO NOTE THAT THE ORIGINAL TOMS ABOARD THE NIMBUS-7 LASTED 14 YEARS. IT'S PLANNED LIFE WAS ONLY 2-3 YEARS. ozfaq.pt4: Subject: 3.) Is UV-B at the earth's surface increasing? ... Several studies [Kerr and McElroy] [Mims] [Seckmayer et al.] [Zerefos et al.] have presented evidence of short-term UV-B increases at middle latitudes associated with the record low ozone levels in 1992-93. As discussed in Part I, these low ozone levels are probably due to stratospheric sulfate aerosols from the 1991 eruption of Mt.Pinatubo;.... COMMENTS: THE SIGNIFICANT OZONE LOWS (AND UV-B HIGHS) THAT I OBSERVED AND REPORTED ON IN GRL WERE ASSOCIATED WITH UNUSUAL CLIMATOLOGY, NOT PINATUBO AEROSOLS. THE RECORD LOW OZONE OVER TEXAS AND MUCH OF THE SE UNITED STATES IN NOVEMBER 1994 (SEE EOS, MARCH 1995), WAS ALSO ASSOCIATED WITH UNUSUAL CLIMATOLOGY. OF COURSE IT IS POSSIBLE THAT PINATUBO MAY HAVE CAUSED CHANGES THAT CONTRIBUTED TO THE UNUSUAL CLIMATOLOGY OF THESE TWO EVENTS. Subject: 8.) What effects does increased UV have upon plant life? Generally harmful, but hard to quantify. COMMENTS: IT IS IMPORTANT TO NOTE THE MANY COUNTER-INTUITIVE EFFECTS THAT OCCUR. RICE, FOR EXAMPLE, MAY BE STUNTED BY HIGH UV-B--BUT MAY STILL DO BETTER THAN RICE ABSENT UV-B SINCE THE UV-B ATTACKS AT LEAST ONE DISEASE THAT ATTACKS RICE. VARIOUS PAPERS HAVE BEEN PUBLISHED ON SIMILAR UNEXPECTED EFFECTS. Subject: 9.) What effects does increased UV have on marine life? Again, generally harmful but hard to quantify. Seawater is surprisingly transparent to UV-B. In clear waters radiation at 315 nm is attenuated by only 14% per meter depth. [Jerlov]. COMMENTS: AT HAPUNA BAY, HAWAII, IN JUNE 1994, MY SON AND I FOUND THAT THE UV-B (310 NM PEAK RESPONSE) AT 1 METER BELOW THE SURFACE OF VERY CLEAR WATER WAS ABOUT 85% OF THAT AT THE SURFACE, WHICH IS VERY CLOSE AGREEMENT TO JERLOV. ON THE OTHER HAND, WE MEASURED NO UV-B ONLY CENTIMETERS BELOW THE SURFACE AT PADRE ISLAND, TEXAS, DUE TO THE EXTREME TURBIDITY CAUSED BY WAVES. Subject: 10.) Is UV-B responsible for the amphibian decline? UV-B may be part of the story, although it is unlikely to be the principal cause of this mysterious event.... Contrary to the impression given by some media reports, Blaustein and coworkers did *not* claim that ozone depletion is "the cause" of the amphibian decline. The decline appears to be world-wide, whereas ozone depletion is restricted to middle and high latitudes. Also, many amphibian species lay their eggs under dense canopies or underground where there is little solar radiation. So, UV should be regarded as one of many stresses that may be acting on amphibian populations. COMMENTS: BLAUSTEIN'S PAPER HAVE ATTRACTED CRITICAL ATTENTION IN VARIOUS JOURNALS DEVOTED TO BIOLOGY. THE MOST IMPORTANT MISSING INGREDIENT TO HIS OTHERWISE WELL PLANNED EXPERIMENTS IS THE LACK OF UV-B DATA. PERHAPS BLAUSTEIN SHOULD COLLABORATE WITH ONE OF THE SEVERAL WORKERS NOW ESTIMATING SURFACE UV-B FROM SATELLITE OZONE MEASUREMENTS. THIS WOULD CERTAINLY GIVE AN IDEA OF THE TREND SINCE 1978. OF COURSE OZONE IS NOT THE ONLY FACTOR THAT MODULATES UV-B. MANY PAPERS HAVE BEEN PUBLISHED ON THE ATTENUATION CAUSED BY CLOUDS. I HAVE DESCRIBED THE VERY SIGNIFICANT ROLES OF HAZE (NEW SCIENTIST, DEC. 1994) AND CUMULUS CLOUDS (NATURE 22 SEP 1994) IN REDISTRIBUTING THE AVAILABLE UV- B. SINCE HAZE AND CLOUDS ARE SO VERY IMPORTANT AND USUALLY CAUSE MUCH MORE MODULATION THAN OZONE, PERHAPS THESE FACTS SHOULD ALSO BE INCLUDED IN THE FAQ. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) Phone: 210-372-0548 Fax: 210-372-2284 e-mail: fmims@aol.com From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re. Ozone faq: Comments Date: 29 Nov 1995 23:27:48 -0500 Lines: 255 In article <49igdd$7jc@peabody.Colorado.EDU>, rparson@spot.Colorado.EDU (Robert Parson) wrote in response to my comments about his very useful ozone faqs. His response and my comments follow. First I wish to thank Robert Parson for the considerable time he has devoted to explaining ozone and UV in his faqs, which I highly recommend. The purpose of my comments is to point out areas of ozone and UV research that are far from complete or where questions remain unanswered. Unfortunately, the ozone matter has for many become a paradigm where science has all the answers. This leaves some of us who actually measure ozone and UV open to criticism from those who question or reject the paradigm. (I have experienced such criticism.) An excellent and highly unfortunate example of a paradigm gone awry might very well be the recent paper by Shorter et al. in NATURE that concludes bacteria in soil are a highly significant sink for methyl bromide. Most methyl bromide is produced by marine creatures and biomass burning. Some is manufactured and used to fumigate soil in which certain important crops are grown (tomatoes and strawberries come to mind). Although the Shorter paper casts serious doubt on the need for EPA rules that ban methyl bromide production or importation after 1 Jan 2001, EPA has a new web page on methyl bromide which has not been updated since the Shorter paper was published. The page firmly states that manufacturerd methyl bromide poses a serious hazard to the ozone layer and offers rather stern advice and warnings to those who would attempt to delay the methyl bromide ban. This is precisely the kind of material that will result in phone calls to SPAN. (I am awaiting a response to a phone call and an e-mail to EPA representatives on this. A preliminary response was that the EPA position and even incorrect statements on its web page will remain in place for the time being.) The obvious lesson is that scientific studies should be completed before, not after, significant policy decisions are made. (In the case of methyl bromide, there are no known substitutes for fumigating soils in which certain crops are raised.) I am very pleased that Robert Parson discussed the latest findings on methyl bromide in his recent faq update. This certainly enhances the objectivity and credibility of his faqs. In the interest of full disclosure, it seems appropriate to point out that the Sun Photometer Atmospheric Network strives to make objective and accurate scientific measurements and has received no support from any group or corporation that may benefit from production of substances believed to deplete ozone. Our instruments were financed with a 1993 Rolex Award. We have also received two small grants from the Informedia Group, which has a special interest in monitoring UV. I have personally financed much of SPAN's work, and any money I receive over expenses from a recent trip to Brazil to measure ozone and UV-B for NASA will be used to purchase SPAN research instruments. The source of virtually all my income since 1970 has been the sale of my books, articles and photographs about science, technology and various other subjects. I have received personal income for writing news and feature articles about ozone and UV. SPAN gladly cooperates with any objective scientists and educators who measure ozone, UV, optical depth and related parameters. We have worked closely and exchanged data with scientists at various universities, NASA, NOAA, EPA and other organizations and hope to continue to do so in the future. My reply (IN CAPS) to Robert Parson follows: In article <49gtbu$6t1@newsbf02.news.aol.com>, FMims <fmims@aol.com> wrote: > >I offer the following updates and comments (in >CAPS). (Please read the introduction to the >relevant faq before using or citing the faq >extracts that follow.) > >Subject: 1.2) How has stratospheric chlorine >changed with time? > >The total amount of chlorine in the stratosphere >has increased by a factor of 2.5 since 1975 >[Solomon] During this time period the known >natural sources have shown no major increases. > >COMMENTS: AS NOTED ELSEWHERE IN THE FAQ, NATURAL >METHYL CHLORIDE MAY ACCOUNT FOR 15-20% OF >CHLORINE IN THE STRATOSPHERE. PERHAPS IT HAS NOT >INCREASED, BUT THE RESULTS OF MANY INQUIRIES ON >THE NET, PHONE CALLS AND A LITERATURE SEARCH SHOW >THAT THIS GAS IS APPARENTLY NOT REGULARLY >MONITORED IN THE STRATOSPHERE. SINCE A MAJOR >SOURCE IS BIOMASS BURNING, WHICH HAS INCREASED >SUBSTANTIALLY SINCE 1978, IS IT NOT PREMATURE TO >STATE IT HAS NOT INCREASED? According to WMO 1994, p 2.7, "Data collected from the late 1970's to mid 1980's showed no long term trends." (Reference is given to work by Khalil and Rasmussen; I'll check this when I get a chance.) I AM QUITE SURPRISED THAT WMO RELIED ON A SINGLE CITATION TO CONCLUDE THAT UNSPECIFIED OBSERVATIONS OVER ONLY CA. 6-7 YEARS RULE OUT A "LONG-TERM TREND." ALTHOUGH I NOW HAVE MORE THAN 6 YEARS OF CONTINUOUS OZONE, UV-B AND AOT DATA IT NEVER OCCURRED TO ME THAT WMO MIGHT CONSIDER THIS AS "LONG TERM DATA." This is the period when manmade halocarbon abundances were increasing by a factor of two. You have elsewhere suggested that since biomass burning increased dramatically in the late 1980's, there may subsequently have been an increase in CH3Cl. This is an interesting suggestion but it does not affect the argument being made in this part of the FAQ. (The post-1985 measurements that I've found so far are all in the neighborhood of 0.6 ppbv, which suggest to me that increases since 1985 have not been dramatic, though I agree that individual measurements made in different places using different techniques are no substitute for continuous monitoring.) IF CH3CL HAS INCREASED, THEN IT DOES MAKE A DIFFERENCE. FOR EXAMPLE, COULD A CH3CL INCREASE NOT ACCOUNTED FOR IN CURRENT MODELS EXPLAIN WHY THE MODELS HAVE NOT FULLY EXPLAINED THE MAGNITUDE OF OZONE LOSS? >COMMENTS: A WORD SEARCH DID NOT FIND MOUNT EREBUS >IN THE FAQ (BUT THE END OF THREE PARTS WAS >SOMEHOW CUT OFF WHAT I RECEIVED). EREBUS, A VERY >UNUSUAL AND PERSISTENTLY ACTIVE VOLCANO, IS A >MAJOR SOURCE OF CHLORINE IN ANTARCTICA, WHICH IS >NOTED FOR ITS EXCEPTIONALLY DRY ATMOSPHERE. The dryness doesn't seem too important given the amount of water vapor in the volcanic plume in the first place. ARE YOU SURE? CAN YOU PLEASE PROVIDE A REFERENCE FOR THE AMOUNT OF WATER VAPOR IN THE EREBUS PLUME? MY PRRIMARY SOURCE (D. S. SHEPPARD, "COMPOSITIONS AND MASS FLUXES OF THE MOUNT EREBUS VOLCANIC PLUME," VOLCANOLOGICAL AND ENVIRONMENTAL STUDIES OF MOUNT EREBUS, ANTARCTICA, ANTARCTIC RESEARCH SERIES, VOL. 66, AMERICAN GEOPHYSICAL UNION, 1994, PP. 83-96) DOES NOT DISCUSS WATER VAPOR. IT DOES, HOWEVER, REPORT 6.5 Mg/D CL AND 2.4 Mg/D SO2 ON 1 JAN 1990. >CLEARLY THIS CHLORINE IS NOT REMOVED AS RAPIDLY >AS IN WETTER LOCATIONS. THE SUMMIT OF EREBUS IS >BELOW THE TROPOPAUSE, AND I AM AWARE OF NO >MECHANISM WHICH MIGHT TRANSPORT SOME OF THIS >CHLORINE INTO THE STRATOSPHERE. BUT CURRENT >OBSERVATIONS HAVE YET TO COMPLETELY RULE OUT A >CONTRIBUTION OF EREBUS EMISSIONS TO OZONE DECLINE >IN ANTARCTICA. I think that the HALOE measurements of stratospheric HCl concentrations count strongly against any tropospheric HCl source, volcanic or otherwise. There just isn't any HCl in the lowest part of the stratosphere over antarctica or anywhere else. (There's a link to the HALOE home page in my FAQ.) I AM AWARE OF THE HALOE RESULTS. THE QUESTION, IS WHERE DOES THE CL (AND THE FL) FROM EREBUS EVENTUALLY GO? WHAT EVIDENCE IS THERE THAT ALL THE CL IN THE PLUME IS IN THE FORM OF HCL? HCL HAS BEEN FOUND IN SNOW NEAR THE VOLCANO. >...Today there are several satellites monitoring >ozone and other atmospheric gases; the Russian >Meteor-3 carries a new TOMS.... > >COMMENTS: UNFORTUNATELY, METEOR-3/TOMS CEASED >FUNCTIONING NEARLY A YEAR AGO (DECEMBER 1994). Right. I try to keep things up to date but I always miss something. >THIS IS A MAJOR SETBACK TO GLOBAL OZONE >MONITORING SINCE TOMS IS BY FAR THE BEST AND MOST >ACCURATE SATELLITE OZONE MAPPING INSTRUMENT. >ALTHOUGH TOMS CANNOT MEASURE OZONE IN THE LOWER >TROPOSPHERE, WHEN A CORRECTION FACTOR IS ADDED >ITS MEASUREMENTS ARE WITHIN A FEW PERCENT OF >THOSE BY GROUND-BASED INSTRUMENTS, INCLUDING >THOSE OF THE SUN PHOTOMETER ATMOSPHERIC NETWORK >(SPAN). Actually I ought to put in a reference to SPAN here; if you'ld like to write a 1-paragraph description (or point me to a reference giving a brief overview) I'll put it in. THANK YOU KINDLY. I WILL SEND YOU A PARAGRAPH SOON. >... Several studies [Kerr and McElroy] [Mims] >[Seckmayer et al.] [Zerefos et al.] have >presented evidence of short-term UV-B increases >at middle latitudes associated with the record >low ozone levels in 1992-93. As discussed in Part >I, these low ozone levels are probably due to >stratospheric sulfate aerosols from the 1991 >eruption of Mt.Pinatubo;.... > >COMMENTS: THE SIGNIFICANT OZONE LOWS (AND UV-B >HIGHS) THAT I OBSERVED AND REPORTED ON IN GRL >WERE ASSOCIATED WITH UNUSUAL CLIMATOLOGY, NOT >PINATUBO AEROSOLS. Yes, that was the wrong place to put the reference to your paper; the second sentence refers properly to the other three citations but not to yours. Sorry. (Gack - I cited your paper in part because Michaels et al. misintepreted your preprint, but I ended up implying the same sort of misinterpretation.) AS AN ASIDE, MY PAPER IN GRL WAS ORIGINALLY SENT TO SCIENCE, WHERE IT RECEIVED WHAT SCIENCE CHARACTERIZED AS 2 "FAVORABLE" REVIEWS. THEY THEN DECLINED TO PUBLISH IT. I THEN SENT THE PAPER TO GRL. WHILE I WAS GLAD TO PERMIT MICHAELS AND SINGER TO CITE THE UNPUBLISHED PAPER IN THEIR LETTER IN SCIENCE, I WAS DISAPPOINTED THAT THEY MISINTERPRETED MY FINDINGS. SCIENCE PERMITTED ME TO CORRECT THE RECORD IN A SUBSEQUENT LETTER TO THE EDITOR. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: House Global Warming Hearing Date: 3 Dec 1995 17:45:56 -0500 This is in response to posts questioning my prior assertions regarding government scientists and administrations that advocate specific scientific agendas before the requisite research has been completed. Recently while speaking with a prominent government scientist, I specifically asked if he knew of instances in which political agendas had ever interfered with scientific research. The response was laughter and surprise that I would ask about what is such common knowledge. (I am aware of several such instances at this scientist's laboratory.) On a related topic, Rich Puchalsky wrote that the firing of a Department of Energy (DOE) scientist by the Clinton administration was "probably mythical," and Len Evens asked for verification. The story is quite true, and I have personal knowledge that the Happer incident made an impact on at least some government scientists and contractors who study environmental matters. Since the story received widespread media coverage, I am surprised it is unknown to Puchalsky and Evens. According to SCIENCE (vol. 260, p. 743, 7 May 93), William Happer, former energy research director at DOE, was "...popular enough in the scientific community that he was among a handful of Bush appointees whom the Clinton administration specifically retained earlier this year. But he's now leaving--apparently given the boot, that is because of some of his environmental views." "Happer's fall from grace, according to associates, can be traced to his very public opinion that the health threat of ozone depletion is overstated. Specifically, Happer points out what he sees as a 'discrepancy' between predicted levels of UV-B, the cancer-causing radiation that ozone normally blocks, and levels actually measured on the ground....Contrast Happer's views with those of Vice President Al Gore, whose apocalyptic vision of an environmentally ravaged Earth drew the epithet 'Ozone Man' during the presidential race last year. Something was bound to give, and that, it seems, was Happer's job. DOE sources say Gore's office made it clear that Happer was no longer welcome to stay." (The news story continues along these lines.) While I do not necessarily agree with Happer's conclusions, one can hardly disagree with his call for for the establishment of a scientific network to monitor UV-B. Funding for the NOAA supported Berger network was ended in 1988 after publication of a paper in SCIENCE reporting a slight decline in UV-B when concurrent slight decline in ozone was expected to have caused an increase. (This is the study to which Happer referred. The difference has been attributed to the location of the instruments in regions with growing air pollution and to calibration uncertainties in the instruments.) While there is no such UV network as yet, within the past few years more than a dozen Federal agencies have established various kinds of UV-B monitoring programs. Unfortunately, these programs are largely uncoordinated and use different kinds of instruments. SPAN is an independent network of volunteers who objectively monitor total ozone, direct UV-B and optical depth. The views in this post are my own. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: House Global Warming Hearing Date: 6 Dec 1995 11:59:45 -0500 Lines: 83 In a prior post to this thread about the unfortunate case of William Happer, I quoted from a news article in SCIENCE about the incident, which one poster had claimed was mythical. This post raised further questions from respondents. And subsequent posts have continued to ask if the incident actually occurred. Some posts and a private e-mail from persons who originally questioned the facts in this matter have now suggested that the matter should now be closed. As stated earlier, the incident did indeed occur and received widespread coverage in the media. A much longer account (including an interview) than the SCIENCE story appeared in the highly reputable magazine PHYSICS TODAY (June 1993): "HAPPER LEAVES DOE UNDER OZONE CLOUD FOR VIOLATING POLITICAL CORRECTNESS" "These are turbulent times in Washington for science. Consider the case of William Happer, who was dismissed from his post as director of energy research at the Department of Energy after opposing the prevailing views of Vice President Al Gore Jr. and his environmental aides on the harmful effects of ozone depletion and greenhouse gases on the Earth's environment and on human health. Happer's dispute with Gore's people is the first instance of the Clinton Administration enforcing its version of 'political correctness' on scientists in its midst. The sacking of Happer, a former Princeton University physics professor with impressive credentials, raises questions about whether the Administration will be able to recruit scientists for sensitive positions when science conflicts with politics." (From Physics Today, June 1993, pp. 89-91; copyright 1993 by Physics Today) The lengthy article goes on to point out how Happer recommended "new and better placed instrumentation to measure UV-B" and that Robert T. Watson, who is now at the White House, and other advocates of the current ozone paradigm reviewed the proposal. "The response, not surprisingly under the circumstances, was that Happer's advice was no longer needed." The article includes an interview with Happer, who, it says, "spoke with candor and some courage." While I do not necessarily agree with all of Happer's positions, it is absolutely astonishing that his recommendation to establish a UV network was considered out of order. This is not new. Under a different administration the government ceased funding the Berger UV network when it showed that UV had decreased during the same period that ozone had also decreased. (This occurred in 1999 and is why I then began designing and making instruments to measure UV-B and total ozone.) The Happer episode clearly establishes that the validity of the points I raised early on in this debate concerning the difficulty of keeping science objective when politicians in charge at the time have conflicting agendas. The Clinton Administration certainly has no monopoly on the unfortunate practice of suppressing the views of scientists with which it disagrees since previous administrations have done the same thing. The Sun Photometer Atmospheric Network (SPAN) cooperates with many individual, university, and government scientists and observers. SPAN has absolutely no political agenda and advocates only the gathering of objective scientific data. The views herein are my own. Forrest M. Mims III Sun Photometer Atmospheric network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: House Global Warming Hearing Date: 7 Dec 1995 14:45:49 -0500 This is in response to Rich Puchalsky (richp@upx.net) and Tom Gray (tomgray@igc.apc.org). Rich Puchalsky wrote (in part): >Whoa. No one has suggested that Mims is not a >dedicated and intelligent scientist. I, at >least, was only objecting to his repeated >summarizing of the Happer story in a way that >seemed to evoke a certain partisan political >slant. Specifically, the first time the story was >told Happer was not mentioned by name, although >Gore was. The Happer incident was not what I had in mind when my initial post was sent. I had in mind specific examples of civil servants--not political appointees--whose research has been affected by various political agendas. I did not go into detail because I was asked not to do so. As for Happer, I posted the excerpt from SCIENCE only because Pulasky characterized it as mythical. "Partisan political slant": As I have stated elsewhere in this forum, the Happer incident is not original with the current administration. It simply corroborates my original point about the difficulty of attempting to reconciling objective science with political agendas, any political agendas. My personal belief about political appointees is that administrations should hire and fire whoever they want. The public can evaluate such actions as it chooses. One way to keep science objective is to keep scientists from becoming political appointees. Another is to erect buffers between science and government funding of science. As for Gore, I invoked his name only because he was mentioned in the hearings about which this thread was begun. Tom Gray writes: >Thanks for the PHYSICS TODAY excerpt on Hopper's >dismissal, Forrest. >I'll simply point out that again, only one side >of the story--Hopper's--is given. If there is a >response, any response, from Gore's office, it >is missing from the excerpt. Details of such a >response, even if it is "no comment," are >required for any semblance of balanced reporting. The PHYSICS TODAY article does include a brief paraphrase of a response from a Gore aide that doesn't directly pertain to the issue at hand. The level of this discussion would be raised if par- ticipants would read this and other contemporaneous accounts of the Happer episode. I would post more of the PHYSICS TODAY piece, but it is quite long, and it is also copyrighted. It should be available in most libraries. (See PHYSICS TODAY, Vol. 46, No. 6, June 1993, pp. 89-91.) These comments are my own. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: House Global Warming Hearing Date: 8 Dec 1995 16:00:42 -0500 Lines: 19 Rich Puchalsky writes: >And to complete the muddying of the issue, >Mims has now clarified that he >at least wasn't even talking about Happer originally, >although he can't reveal just who he was talking about. An issue is not muddied by clarification. I did not introduce the Happer matter because it was not on my mind. I merely confirmed it with quotes from news stories after Puchalsky claimed it was a myth. Apparently he now accepts the story. Since this issue came up, I have heard from various scientists who have personal knowledge of the suppression of appropriate scientific inquiry. While it would be best if they would come forward, that is their decision, not mine. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: HR 475, More Freon = Less Ozone Date: 22 Dec 1995 12:45:22 -0500 Len Evans (len@schur.math.nwu.edu) responded to John McCarthy's (jmc@cs.Stanford.EDU) comments on ozone and UV-B. I would like to append the following comments to their exchange and to other comments made about UV-B in Antarctica: McCarthy: >And yet, there is one small problem left. The >harm from thinning the ozone layer is supposed to >be increased UV-B at ground level. There >is apparently a lack of evidence that this has >occurred. Significant ozone decline over Antarctica during the spring causes significant increases in UV-B. There are various reports about increased UV-B where people live, but most of the increases may not exceed natural variation. Exceptions have occurred at times of the year when the Sun angle is well below the summer maximum. Keep in mind that total ozone in 1962 was apparently lower (over the U.S.) than just prior to the eruption of Pinatubo in 1991. Indeed, the ozone increase during the 1960s is similar to the decrease observed since the 1980's. Various other posts discussed UV-B in Antarctica. One of the best sources on this is "Ultraviolet Radiation in Antarctica: Measurements and Biological Effects" (C. S. Weiler & P. A. Penhale, eds., Antarctic Research Series, Vol. 62, American Geophysical Union, 1994). From my personal experience measuring UV-B, water vapor-based haze (both natural and anthropogenic); volcanic haze (Big Island of Hawaii); and smoke (1988: Yellowstone fire smoke over Texas; 1995: biomass smoke in Brazil) reduce UV-B far more than ozone changes during a typical summer (paper in preparation). And scattering from cumulus and cum. congestus clouds increases UV-B far more than ozone changes during a typical summer (F. M. Mims II, Nature, 22 Sep 1994). Evans: >Do you mean there is no evidence of increased UVB >at ground level or that there is not a large >amount of evidence? Other factors >being kept eual, it has been fairly well >established that where the ozone level is thinned >there is increased UVB at the surface. The problem is that it's virtually impossible to keep things equal in places where people live. Anthropogenic pollution can significantly reduce UV-B over very large geographic regions (a by- product of multiple scattering caused by aerosols and absorption caused by ozone). This is especially obvious in the Eastern U.S. during summer. >This is clear on rather simple theoretical >grounds and also by observational studies. Read >Robert Parson's FAQ and see in particular his >remarks about the Antarctic where the evidence is >absolutely clear and also about the Toronto >studies. Parson's FAQ is a very good start, but it fails to discuss modulating influences that, from a purely practical perspective, remain much more important than column ozone. Cumulus clouds in a clear sky can increase UV-B by 25% for 30 minutes or longer. This is a measured, not modelled, result. The measurement has been repeated and validated for Hawaii (1994-5). >The problem in science in general and geoscience >in particular is that other factors are >seldom kept constant. It seems to me that some >people have used this fact to muddy the basic >point. Good point. The various ozone FAQs either ignore or fail to adequately discuss the modulating effects of haze, smoke and clouds. The "Scientific Assessment of Ozone Depletion: 1994 (WMO Report No. 37, 1995), which devotes more than 500 pages to ozone and only 22 to UV-B. The report does not give explain exactly how the sites used to compute ozone trends are selected (data from many sites are not used). The report overemphasizes atmospheric chemistry and underemphasizes meteorology. The report is not unanimously endorsed by its writers (as implied in WMO and EPA statements). The discussion of contamination of the trend record by changes in sulfur dioxide pollution is inadequate (see p. 1.7). The study arbitrarily associates population density with SO2 pollution. The study also claims that the SO2- induced erroneous ozone decline at Uccle, Belgium, occurred in a region more polluted than other regions of Europe. However, various published maps of sulfates over Europe and Asia show very high levels over much of Europe and Russia. (No such maps are shown in the WMO report.) This report includes many other gaps and inconsistencies which I plan to address later. >One cannot approach this sort >of thing at a purely empirical level: I >measured UVB at such and such a location for such >and such a period and this is what I saw. The >observations have to be fit into the overall >theoretical structure. Often that requires a >quite broad understanding of the whole field. I agree. This is why SPAN observers measure ozone, direct UV-B, column water vapor and optical depth simultaneously and with the same instrument. Papers (and FAQS) that describe only one parameter (say UV-B) without also providing data about other parameters that modulate the measured parameter are incomplete and should not be published. But they continue to be published. >The whole issue has been complicated by the >absence of an extensive network of stations to >observe UVB. This should be funded. I've >seem at least two explanations of why this has >not yet been done, one suggesting failure or >conspiracy among some group or other and >the other suggesting a lack of agreement among >scientists on how best to measure the relevant >frequencies. In any case it should >be done. However, given the many confounding >factors and the so far moderate decline in ozone >levels in temperate regions, it >may take quite a while before observations catch >up with theory in this matter. Many scientists have long recommended this. As of 1995, some 13 U.S. Federal agencies are now measuring UV-B. But the effort is highly uncoordinated and the instruments are not necessarily compatible. It is urgent that the Federal effort be coordinated and placed under the umbrella of an experienced senior scientist. NOAA's John DeLuisi comes to mind. Another good candidate is John Frederick, who heads the geoscience department at the University of Chicago. >And it is always possible we may be surprised. >For example, although UVB increases in the >Antarctic have been clearly demonstrated to be >related to ozone depletion, it is possible that >there is some as yet not understood factor which >will prevent similar things from happening in >temperate regions given large ozone >depletion there. Right. Like sulfate haze. The kind most of us produce when we drive, fly and send e-mail like this. (Fortunately my PC power comes from a hydroelectric power plant.) >But at present we have to go with the best >knowledge we have. And that suggests that >allowing the ozone layer to continue to thin with >extreme perturbations already observed in polar >regions is not a sensible experiment. Your premise is that ozone thinning is strictly a byproduct of CFCs and that human activity can somehow alter the rate of decline. But there are other possibilities, and present trend studies do not all agree. The 1994 Ozone Assessment so often cited in this news group and by the EPA states on p. 1.7, "Sulfur dioxide (SO2) absorbs ultraviolet at the wavelengths used by Dobson and Brewer instruments to measure total ozone. The presence of SO2 causes a false increase of total ozone measured by Dobson instruments...." (See my comments above.) Also, various published papers, some very recent, take issue with the prevailing view that decomposed CFCs and related compounds cause most ozone decline. Few such papers are cited in the 1994 assessment. One recent paper attributes ozone decline to predominantly meteorological processes and concludes, "The question of so-called 'ozone depletion' has to be investigated from the point of view of long-term variations of general circulation in the atmosphere. Models of 'the depletion', as summarized in the WMO Report (1991), must realize that the meteorological conditions have significant effects on the ozone layer, being the main cause of seasonal as well as most of the shorter and apparently arbitrary density and thermal variations." (K. Henriksen & V. Roldugin, "Total Ozone Variations in Middle Asia and Dynamic Meteorological Processes in the Atmosphere," Geophysical Research Letters, 22, 23, 3219-3222, 1 Dec 1995.) Hopefully this paper will be cited in the next WMO report. Since some scientists who do not necessarily agree with the prevailing ozone depletion hypothesis have been criticized or ignored, I know from personal experience that papers published in GRL are subjected to vigorous peer review. This is probably why the paper cited above was revised after initial submission. >Since the economic effects of shifts to >substitutes for CFCs are already >underway---without disasterous consequences, by >the way---we should >continue on the current path. We certainly >won't get absolutely everything just exactly >right, but that is is no reason for overturning >the mechanisms previously agreed to by our >government. About all I can say to this is that current policy is based on incomplete and even questionable science. When I asked a contributor to the 1994 ozone assessment why the same people seem to rotate as leaders of this effort and why the WMO studies are dominated by atmospheric chemistry and devote so little space to meteorology and UV-B, he laughed and said, "They reappoint each other." While I'll be glad to respond to respondents, I will be in and out during January and may not be able to respond promptly. These comments are my own and do not necessarily reflect the position of SPAN. The sole purpose of SPAN is to collect objective data. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment,sci.geo.meteorology Subject: Re: House Global Warming Hearing Date: 22 Dec 1995 12:51:29 -0500 Lines: 62 R. T. Pierrehumbert <rtp1@midway.uchicago.edu>, in response to my previous comment, writes: >Mims: >>Since CO2 levels were considerably higher in the >>distant past, it's reasonable to assume that a >>negative feedback mechanism of some kind does >>exist. Pierrehumbert: >Actually, the inference from paleoclimate is >exactly the reverse of this. The usual problem >with explaining Cretaceous climates is >not that they are too warm but that even with 6x >CO2 they can be, if anything, too cool. With >something like 6xCO2, one can get a climate that >is roughly as warm as the Cretaceous >in models where the water vapor feedback behaves >as it does in the models that predict fairly >large global warming from doubling CO2; the water >vapor feedback in such models behaves such that >the relative humidity stays roughly constant. [deletion...] You cite models. Although I make use of UV-B and total ozone models several times each day (while measuring these parameters), I have learned to respect their limitations. Have your models been tested and, if so, can they explain the long-term trend in increased cloud cover? An increase in cloudiness is commonly mentioned as a possible negative feedback consequence of global warming. A very obvious increase in cloudiness has occurred since the turn of the century over various regions. For example: Six sites in Illinois reported a significant increase in cloudy days from 1901-10 (1120 cloudy days) to 1971-80 (1710 cloudy days). (See S. A. Changnon, "Climate Fluctuations and Impacts," Bul. of the Am. Meteo. Soc., 66, 142-151, 1984.) Average cloudiness over the United States rose from 0.5 of the full sky to 0.61 between 1900 and 1980. An increase over this period was reported by 76 of 77 U. S. stations. (See Edward Linacre, "Climate Data and Resources," 190, Routledge, London, 1992.) These increases in cloud cover approximately match the increase in global temperatures since the turn of the century. I will be most appreciative if you cite references in which models explain these changes in cloud cover. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: OZONE DEPLETION & HEALTH RISKS Date: 23 Dec 1995 23:13:08 -0500 In article <4bfgm7$jlg@gap.cco.caltech.edu>, Carl J. Lydick <carl@SOL1.GPS.CALTECH.EDU> wrote: >In article <APC&1'0'576a999e'a97@igc.apc.org>, "Nicholas A. Sundt" ><nsundt@igc.apc.org> writes: >= >= MIDDLE-LATITUDE OZONE DEPLETION INCREASES HEALTH RISKS >= >=According to the National Cancer Institute, between 1973 and 1992 >=the incidence of melanoma, a serious form of skin cancer, >=increased faster than any other cancer among caucasians in the >=US. Now accounting for 3% of cancers diagnosed nationwide, the >=American Academy of Dermatology calls melanoma "an undeclared >=epidemic." >= >=This alarming trend may persist or even accelerate for at least >=one reason: stratospheric ozone is being depleted, allowing >=additional damaging ultraviolet (UV-B) radiation to penetrate >=into the lower atmosphere. >Of course, that trend occurred after a decade or two of folks being >obsessed with tanning. Why is it that you fail to mention that rather >relevant fact? The connection of melanoma with UV-B remains tenuous. For example, it is believed by some that susceptability to melanoma in adulthood can be enhanced by a predisposition to the disease and by as few as one or two severe sunburns during youth. There are other possible correlations. As Lydick observes, this is a lifestyle problem having nothing to do with observed increases in UV-B due to changes in ozone, at least to date. A major Canadian study found a correlation of skin cancer and exposure to the Sun received by Canadians who visit the Caribbean, certainly not an unexpected finding. Ozone decline is involved here only to the extent that there is ordinarily less column ozone over the latitudes of the Caribbean than over Canada. (This doesn't always hold in the post-Pinatubo era.) Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment,sci.geo.meteorology Subject: Re: House Global Warming Hearing Date: 24 Dec 1995 00:11:21 -0500 Lines: 110 Pierrehumbert wrote: >Mims: >>You cite models. Although I make use of UV-B and >>total ozone models several times each day (while >>measuring these parameters), >No, I cite paleoclimate history as evidence of >consistency with model behavior. Then, as I wrote, you cite models. (See below...) >The sort of behavior I am talking about is >really pretty robust and not so much in the >details about how the models are written. If >there is a strong stabilizing water vapor >feedback (contrary to what models yield) then it >is very hard indeed to account for warm >Cretaceous temperatures. >You cite a lot of cloud observations that are >mostly irrelevant to the question of Cretaceous >warmth. If you have a way of accounting for >Cretaceous warmth with cloud effects and >no CO2 increase, you should publish it and you'll >become instantly famous. I've been trying to get >clouds to bump up Cretaceous warmth myself. It's >not so easy. I cited only the increase in cloud cover since the turn of the present century. I have no idea how one can extrapolate present cloudiness to that during the Cretaceous. The present concerns over global warming apply to the present and proposed temperature increases over the next century. Pierrehumbert posted a followup before this response: >I forgot to mention also that Mims failed to >respond to my comment pointing out that his >measurement does not measure the aspect of water >vapor of relevance to global warming. Total column water vapor and the stratification of water vapor are absolutely relevant to global warming. CO2 is a greenhouse gas. But the greenhouse effect of water vapor dwarfs that of CO2. >All he's interested in doing is taking potshots >at models. As noted in my post, I use models daily. But I use them with due caution and, as stated, have learned to understand their limitations. Here is the exact wording I used: >You cite models. Although I make use of UV-B and >total ozone models several times each day (while >measuring these parameters), I have learned to >respect their limitations. Have your models been >tested and, if so, can they explain the long-term >trend in increased cloud cover? Models are simply models. Heterogeneous and gas- phase chemistry models that attempt to explain the decline in ozone observed since the 1980's underestimate the decline. These same models also fail to explain the significant increase in ozone that occurred during the 1960's. The Canadian AES model I use that predicts total-sky UV-B (knowing the column ozone and the Sun angle) works quite well when the optical depth is relatively small (i.e. little haze). The model estimates are always too high when haze is present. Models must consider all relevant variables. In Brazil this August, I was surprised to find that the measured UV-B was sometimes only 20% of the modeled UV-B because the model fails to take into account the absorption of UV-B by black carbon in the abundant smoke from biomass burning. None of the UV-B models can adequately account for smoke and haze. Although I am not a climate modeler, I have read several reports that some climate models have failed to adequately track recent climatology. So I repeat my questions: 1. Have any of your models been tested against known climatology? What were the results of the test(s)? (Please indicate if your model(s) are not designed for such short term tests.) 2. Do your models explain the increase in cloud cover since the turn of the century? I add an additional question about a topic in which I have considerable interest: 3. Do your model(s) account for changes in aerosols? If so, can you study the separate effects of changes in stratospheric and tropospheric aerosols? (I particularly have in mind aerosols arising from volcanoes and fires.) Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: HR 475, More Freon = Less Ozone Date: 26 Dec 1995 13:33:57 -0500 Len Evens (len@schur.math.nwu.edu) writes(in part): [Mims:] >>About all I can say to this is that current policy >>is based on incomplete and even questionable >>science. When I asked a contributor to the 1994 >>ozone assessment why the same people seem to >>rotate as leaders of this effort and why the WMO >>studies are dominated by atmospheric chemistry >>and devote so little space to meteorology and UV-B, >>he laughed and said, "They reappoint each other." [Evans:] >I think this is the same argument which various >critics of the ozone ban have been claiming since >the beginning: since we don't know everything, we >don't know anything. I do not accept the premise that nothing is known until all is known. If I have ever posted such, I request that Evans provide the citation. > Mims doesn't say outright that he >opposes the ban, but the above quote certainly suggests >that it is not warranted by the scientific evidence. >Let me say again what I consider >the obvious. Without getting mired in detail, the appearance >of the antarctic ozone hole alone---which by the way is >explained in part by `meteorological' analysis---is >dramatic reason enough to justify the ban. THIS IS A >VERY MAJOR CHANGE in the atmosphere which as best we can >tell so far is unprecedented. I speak simply as a >as an informed amateur, and I am afraid I cannot side with >Mims in his apparent battle with the `atmospheric chemists'. I have no battle with chemists. The most important member of the SPAN network and the developer of the SPAN ozone algorithm is a professor of chemistry. My only "battle" is with incomplete and non- objective science. I decided to begin measuring UV-B in 1988 after the government decided to stop measuring UV-B (by funding the country's only UV-B network) at the same time the same government claimed there was significant ozone decline. There was clearly something amiss then, and there is more amiss now. I have discussed the Antarctic ozone hole in prior posts. Yes, there is a strong inverse correlation in ozone and Cl0 during the ozone hole season. Yet James Lovelock believes the hole might be the consequence of increasing methane. Walter Komhyr (see below) believes it may be largely a consequence of warming of the tropical Pacific. I cited various significant problems in measuring ozone decline in the post to which Evans responds. But he did not respond to these. So here's another from my list: One-third of the global ground-based ozone network uses Russian M83 or M124 ozonometers. These data are used in the trend analysis given in various papers and in the 1994 assessment. Yet the M83/M124 can have significant errors. For example, A. M. Thompson et al. reported in "Ozone Observations and a Model of Marine Boundary Layer Photochemistry During SAGA 3" (J. of Geophysical Research, 98, D9, 16,955- 16,968, 20 Sep 1993) that the M-83 from the Main Geophysical Observatory at St. Petersburg, Russia, gave ozone amounts from 10 to 30 Dobson units below TOMS. They cite a prominent Russian expert in affirming that the "TOMS-SAGA-M83 discrepancy, which ranges from 10 to 30 DU (4-11% of TOMS O3), is probably within the accuracy of the M83 instrument." (See p. 16, 960; see also Fig. 5 on p. 16, 961.) I have measured very similar differences during fall and winter between TOMS and one of two M-124s in South Texas from summer 1992 to summer 1994 (including three calibration checks at Mauna Loa Observatory) (paper in preparation). I acquired two M-124's from Russia when I learned in 1992 that M124 data was actually used in trend analysis. If the M-124 data are consistently off due only to solar zenith angle (or air mass) effects, then the data might be usable in limited trend analysis. However, the M124 is also very subject to error from aerosol changes (due to its very large field of view, wide filter bandpass of 20 nm, a very wide separation between observing wavelengths of 24 nm, and the fact wavelengths are not observed simultaneously). The M-124 accuracy problem is simply not mentioned in the various ozone faqs or adequately discussed in the 1994 assessment. >By the way, is there any strong evidence, as shown in the >literature, that a sizeable number of people in meteorology >and related areas of atmospheric science, agree that CFSs >may not be a major factor in ozone depletion and who thus >oppose the ban on CFCs on scientific grounds of incomplete >knowledge? I wasn't aware of it, but maybe I read the >wrong journals. I've seen references to papers which >suggest that other factors may also be important and shouldn't >be ignored in modelling the response. But it was my impression >these were secondary factors and the authors did not oppose >the ban on CFCs. Some papers are cited below. First, it is very difficult for a paper that challenges the conventional paradigm in any field to be published in the first place. For example, in the fall of 1991 after the eruption of Mt. Pinatubo, my son and I measured slight but obvious ozone reductions associated with the Pinatubo aerosol cloud. We also found similar reductions in TOMS zonal means over our latitudinal belt. We wrote a paper which stated that Pinatubo aerosols were associated with a slight but measured reduction in ozone at our Texas site and sent same to a leading journal. The two peer reviewers castigated us, our instruments and the fact we were unknowns in the field for making such a claim. The paper was promptly rejected. Later, of course, our finding was widely confirmed when ozone declined significantly, and many papers were published, including some of mine. (But my initial paper still resides in the folder where it was placed after being rejected.) Walter Komhyr, a contributor to the widely cited "Scientific Assessment of Ozone Depletion: 1994," is the leading U.S. expert on the ground-based measurement of ozone. He established the calibration methods used to make Dobson spectrophotometers 83 and 65 the world's primary and secondary ozone measurement standards. He has long been responsible for the reduction of Dobson 83 data used each year since 1978 to check the calibration of NASA's Total Ozone Mapping Spectrometer. Yet when Komhyr and others wrote a paper on how Pacific warming might play a very significant role in the development of the Antarctic ozone hole, leading U.S. journals rejected his paper. Eventually the paper was published in the CANADIAN JOURNAL OF PHYSICS. And Komhyr's paper on the significant increase in ozone during the 1960's is all but ignored in trend analysis work and in the various faqs. Yet the magnitude of the increase in the 60's approximates that of the decrease since about 1985. Now, you asked: >...is there any strong evidence, as shown in the >literature, that a sizeable number of people in meteorology >and related areas of atmospheric science, agree that CFSs >may not be a major factor in ozone depletion and who thus >oppose the ban on CFCs on scientific grounds of incomplete >knowledge? I don't know. I do know that a sizable number of scientists with whom I have spoken and who give talks at conferences believe that the role of factors aside from CFCs is being overlooked while the bulk of research money goes to study the CFC paradigm. Yet despite incredibly expensive research over 20+ years, many recent papers and the 1994 assessment have noted that the current models, developed primarily by atmospheric chemists, simply do not account for the magnitude of ongoing ozone decline. The role of meteorology in redistributing ozone is crucial. And there are very few measurements of the stratospheric concentration of such important natural ozone depleting gases such as methyl chloride, methyl bromide and methyl iodide. Here are some representative papers that clearly illustrate the difficulty inherent in blaming all of the current ozone situation on CFCs or which seriously question widely held assumptions about ozone decline (please note the paper titles): 1. Komhyr, W. D., S. J. Oltmans, R. D. Grass, and R. K. Leonard, "Possible influence of long-term sea surface temperature anomalies in the tropical Pacific on global ozone," Canadian J. of Physics, 65, 1093-1102, 1991. 2. Henriksen, K. T. Svenoe and S. H. H. Larsen, "On the stability of the ozone layer at Tromso," J. of Atmos. Terr. Phys., 54, 1113-1117, 1992. 3. Henriksen, K. T., E. I. Terez, G. A. Terez, V. Roldugin, T. Svenoe and S. H. H. Larsen, "On the stationarity of the ozone layer in Norway and U.S.S.R.," J. Atmos. Terr. Phys., 55, 145-154, 1993. 4. DeMuer, D. and H. DeBacker, "Revision of 20 years of Dobson total ozone data at Uccle (Belgium): Fictitious Dobson total ozone trends induced by sulphur dioxide trends," J. Geophys. Res., 97, 5921-5937, 1992. 5. DeMuer, D. and H. DeBacker, "Influence of sulphur dioxide trends on Dobson measurements and on electrochemical ozone soundings," Proc. of the Soc. of Photo-Optical Instrumentation Engineers, 2047, 33, 18-26, 1993. 6. DeMuer, D. and H. DeBacker, "Trend analysis of 25 years of regular ozone soundings at Uccle (Belgium), Abstract, EUROTRAC Meeting, Garmisch- Partenkirchen, April 1994. 7. Henriksen K and V. Roldugin, "Total Ozone Variations in Middle Asia and Dynamic Meteorological Processes in the Atmosphere," Geophysical Research Letters, 22, 23, 3219-3222, 1 Dec 1995. Since the last paper is the most recent, it is interesting to note that it directly confronts the conventional ozone paradigm by attributing ozone changes to predominantly meteorological processes. The paper concludes, "The question of so-called 'ozone depletion' has to be investigated from the point of view of long-term variations of general circulation in the atmosphere. Models of 'the depletion', as summarized in the WMO Report (1991), must realize that the meteorological conditions have significant effects on the ozone layer, being the main cause of seasonal as well as most of the shorter and apparently arbitrary density and thermal variations." I began measuring UV in 1988 and ozone in 1989 because I accepted without question the hypothesis that ozone was then in a dangerous and unprecedented decline. I have since personally measured total ozone, UV-B and aerosols in Switzerland, Japan, Hawaii, Brazil and across the U.S. I have learned from attending many meetings and visiting with ozone scientists from dozens of countries that the views espoused by various political organizations and in faqs are sometimes very different from those expressed by scientists who actually measure ozone. I very much hope this discussion will encourage an open-minded, objective view of the ozone situation. And I hope those interested in the ozone layer, especially faq writers, will take the time to read some of the papers cited above. These views are my own. From past experience, I know this post may attract private e-mail from scientists who actually measure or study ozone. While I have very much appreciated such private comments, I encourage them to post their comments on this forum as well. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: HR 475, More Freon = Less Ozone Date: 26 Dec 1995 17:51:57 -0500 My apologies to Len Evens for misspelling his last name on my previous post. Forrest M. Mims III SPAN Newsgroups: sci.environment From: Jim Scanlon <jscanlon@linex.com> Subject: Ultraviolet Studies Ignored orvoided Date: Thu, 28 Dec 1995 05:20:34 GMT I received the following notice of a symposium on Stratospheric Ozone. Please note that in neither Synopsis nor the program is there any mention of Ultraviolet Radiation, the immediate, direct menace to life on earth. Perhaps someone can explain why an indirect study of a surrogate is acceptable so as to infer, or insinuate the direct threat? t? STRATOSPHERIC OZONE SYMPOSIUM AMSIE '96, AAAS Annual Meeting Monday, 12 February 1996,1:00 -5.30 pm Baltimore Convention Center, Baltimore, Maryland Organized by Manvendra K. Dubey, SRI International, Telephone: 415-859-2048 and Darin W. Toohey, University of California-Irvine SYNOPSIS The ongoing global thinning of the stratospheric ozone layer has been attributed to anthropogenically released halogen compounds. The subsequent international control of halocarbons is a paradigm for societal action, based on sound atmospheric science, to a global change problem. The efficacy of this action in reducing the release of halocarbons has been observed. In addition, significant strides in our knowledge of stratospheric chemistry have been made. In spite of this progress, the magnitude of persistent ozone reductions remains less predictable than desired. Improved understanding will be needed to manage decisions on the future of supersonic aviation and methyl bromide use. A concerted effort using stratospheric measurements and improved laboratory studies is underway to refine models of stratospheric photochemistry and circulation. This effort has demonstrated that catalytic ozone destruction by chlorine is pervasive. This symposium will present evidence for known mechanisms of halogen-induced ozone losses and will address efforts to assess its future evolution. The following questions will be discussed: 1) What observational facts demonstrate stratospheric ozone depletion? What is the temporal evolution and global distribution of ozone losses? 2) What are the known mechanisms of ozone destruction by halogens? How do they vary with latitude and season? Why do volcanoes exacerbate ozone losses by halogen catalysis? 3) How effective is the Montreal Protocol in reducing stratospheric chlorine and bromine levels? What threats are still faced by stratospheric ozone? 4) What future perturbations to stratospheric ozone need assessment? Examples of potential perturbations include the evolution of halocarbon, methyl bromide, and hydrogenated halocarbon fluxes; injection of odd nitrogen, water, and soot by future stratospheric aviation; and a higher and cooler stratosphere resulting from the buildup of greenhouse gases. For registration information and details contact AAAS - Meetings Telephone: 202-326-6417 Fax: 202-289-4021 http://www.aaas.org/meetings/meetings.htm AMSIE '96, AAAS Annual Meeting Monday, 12 February 1996,1:00 -5:30 pm Baltimore Convention Center, Baltimore, Maryland STRATOSPHERIC OZONE SYMPOSIUM PROGRAM 1:00 pm Topical Lecture: Halocarbons and stratospheric ozone depletion Prof. F. Sherwood Rowland, University of California-Irvine 2:30 pm Session: Stratospheric ozone depletion by halogens: Recent achievements and continuing challenges Organizers: Dr. Manvendra K. Dubey, SRI International Dr. Darin W. Toohey, University of California-Irvine Chair: Prof. Mario J. Molina, Massachusetts Institute of Technology 2:30 pm Introduction: Stratospheric ozone depletion by halogens Dr. Manvendra K. Dubey, SRI International 2:45 pm Observations of global ozone change Dr. Richard S. Stolarski, NASA Goddard Space Flight Center 3:15 pm Hydrogen- and halogen-catalyzed destruction of ozone: Observed response of the stratosphere Prof. James G. Anderson, Harvard University 3:45 pm Satellite observations of stratospheric reactive chlorine: Implications for ozone Dr. Joe W. Waters, Jet Propulsion Laboratory 4:15 pm Atmospheric impact of Mt. Pinatubo aerosols Dr. M. Patrick McCormick, NASA Langley Research Center 4:45 pm Panel Discussion: Stratospheric ozone depletion: Facts and future issues F. S. Rowland, M. J. Molina, R. S. Stolarski, J. G. Anderson, J. W. Waters, and M. P. McCormick From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: HR 475, More Freon = Less Ozone Date: 28 Dec 1995 10:18:57 -0500 Hugh Easton <hugh@daflight.demon.co.uk> provided an article from NEW SCIENTIST on unusual deaths of penguins and krill. I am no expert on these phenomena. However, I have measured UV-B in the very clear waters off Hawaii and found that the UV-B one meter under the surface retains about 85% of the irradiance at the surface. In short, clean ocean water is highly transparent to UV-B wavelengths. For more information, see "Ultraviolet Radiation in Antarctica: Measurements and Biological Effects" edited by C. S. Weiler and P. A. Penhale (Antarctic Research Series, vo. 62, American Geophysical Union, 1994). Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Ultraviolet Studies Ignored orvoided Date: 28 Dec 1995 10:21:37 -0500 Jim Scanlon's post about the forthcoming meeting on ozone is precisely on target. It is scandalous that so much is spent to measure ozone when so little is spent to measure UV. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: HR 475, More Freon = Less Ozone Date: 8 Jan 1996 00:43:16 -0500 Joshua Halpern (jbh@haven.ios.com), responding to Andrew Russell (arussell@bix.com) on another thread, made various comments about ozone. I will respond to some of them in this and subsequent posts. Halpern suggested: >See the WMO Scientific Assessment of Stratospheric Ozone 1995 While the WMO assessment is an excellent reference, it is incomplete. Here are several problems I noted while scanning this 550+ page document: 1. It fails to adequately discuss the derivation of trends from ground-based data. (I am unaware of any publications in the peer-reviewed literature that describe how ozone time series are corrected and the criteria for rejecting and accepting data from specific instruments. If such publications are available, I will be most grateful to receive their citations.) 2. It fails to adequately discuss significant limitations (described in the peer reviewed literature) of the M-124, the instrument which comprises 1/3 of the ground-based ozone network. The M-124 typically indicates too little ozone at high solar zenith angles (10-40 Dobson units typical) and significant error in the presence of aerosols (due to its large field of view and the wide bandpass of the filters--20 nm--and their wide spacing of 24 nm). M-124 data are completely unreliable when clouds fragments or variable density cloud haze cross the sun during observations. This is because the instrument observes only one channel at any time, and several seconds or more must be allowed for its mechanical meter movement to be checked for zero and to then settle before the second channel is measured. (I used an M-124 regularly for 2+ years and made Langley plots using it at Mauna Loa Observatory in Hawaii in 1992, 1993 and 1994. These limitations of the M-124 are well known, which explains why NASA and NOAA declined my offer of a free M-124. 3. Its discussion of solar ultraviolet is much too brief (only 22 pages). 4. It fails to provide any kind of cost-benefit analysis of ozone research. Nor does it include (unless I missed it) any summaries of money spent on ozone research. 5. It's discussion of volcanic effects on ozone is incomplete. 6. It fails to adequately discuss significant changes in climatology and increases in methane, either of which may lead to significant ozone reductions in polar regions. 7. It's discussion of the sulfur dioxide contamination at Uccle, Belgium, does not provide references for its conclusion that such pollution is highly localized at Uccle when, in fact, several widely available publications describe significant sulfur dioxide and/or sulfate pollution over substantial regions of Europe, Eurasia and North America. (The Uccle group has published papers claiming that ozone decline at their site and possibly elsewhere is "fictitious." They attribute the apparent decline to a reduction of sulfur dioxide as sulfur dioxide pollution has been reduced. The UV absorption bands of sulfur dioxide overlay those of ozone, and, therefore, the presence of SO2 can cause an apparent, not real, increase in ozone.) 8. It devotes little space to the naturally occurring fraction of such ozone depleting gases as methyl chloride, methyl bromide and methyl iodide (all the latter, a "significant" ozone depleter, is believed to be natural in origin). While the WMO and various other groups have depicted the 1995 assessment as a consensus document, it apparently is not. It is simply a selective review and discussion of some of the peer-reviewed literature. I discussed this with a leading scientist listed as a contributor, who stated he had not even seen a copy of the report (beyond his contribution). Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: HR 475, More Freon = Less Ozone Date: 8 Jan 1996 00:43:21 -0500 Joshua Halpern (jbh@haven.ios.com), responding to Andrew Russell, made various comments. I will respond to some of them in this and subsequent posts. Halpern asked Russell: >By the way, can you provide a source claiming a >significant *rise* in ozone occurred during the 60's. A rise in total ozone during the 1960's that matches or exceeds the decline since the mid-1980's is described in several papers. Walter Komhyr, one of the world's leading experts on the ground-based measurement of total ozone, wrote at least two such papers (1, 2). I cite only Komhyr's papers because of their very careful presentation and analysis of the data. Also, he used only data based on a calibration obtained "...on very clear half-days when the ozone amount was believed to remain nearly steady...." (1). The following is from Table 3 in ref. 1 (p. 998): Tallahassee: +4.7% (+/- 1.3) Nashville: +8.8% (+/- 0.7) Boulder: +4,4% (+/- 1.3) Bedford: +5.3% (+/- 1.3) Toronto: +2.7% (+/- 0.9) Green Bay: +2.0% (+/- 1.2) Caribou: +5.9% (+/- 0.9) Goose Bay: +4.4% (+/- 1.1 ) Bismarck: +6.9% (+/- 1.1) Edmonton: +5.1% (+/- 1.0) The mean increase in ozone for these stations matches or slightly exceeds the mean decline in ozone given in the 1995 ozone assessment. The decline since the mid-1980's has been influenced significantly by the annual Antarctic ozone minimum. Please note that the change in ozone absorption coefficients used in this paper (Vigroux) to the new values (Bass-Paur) will affect absolute values by about 5% but should not affect these trends. Walter Kohmyr's expertise and international reputation are well known to those who measure ozone. For many years he was at NOAA's Climate Monitoring and Diagnostics Laboratory (CMDL), where, I believe, he is now on contract through CIRES. Komhyr established the calibration methods used to establish Dobson-83 as the World Standard Dobson Spectrometer (and Dobson 65 as the secondary standard). Since 1978, he has coordinated the annual comparison of Dobson 83 and Nimbus-7/TOMS and, later, Meteor-3 TOMS at Mauna Loa Observatory. Komhyr is also an expert in the measurement of tropospheric ozone and the inventor of a well known ozone sonde flown from meteorological balloons. Komhyr's versatility and his incredibly wide range of experience remind me of Gotz, the pioneering observer who worked closely with Gordon Dobson to establish regular ozone observations in Arosa, Switzerland, in about 1926. If there is serious interest (and if I can find the time), I can discuss very long ozone time series made by the Smithsonian Astrophysical Observatory and at Arosa. I am unaware if the papers published by Komhyr and others on the ozone increase in the 1960's have been retracted by their authors. If this is the case, I will retract this posting. REFERENCES: 1. W. D. Komhyr, R. D. Grass and G. Slocum, "Total Ozone Increase over North America During the 1960's," Pure and Applied Geophysics, 106-108, 981-999, 1973. 2. W. D. Komhyr, E. W. Barrett, G. Slocum and H. K. Weickmass, "Atmospheric Total Ozone Increase during the 1960's," Nature, 232, 390, 1971. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Ozone and UV-B Science Date: 8 Jan 1996 20:10:40 -0500 Discussions of ozone decline on the net are often based on emotional convictions rather than scientific studies. Hence this new thread. I am hopeful that the level of this discussion will be raised by the inclusion of comments from professionals in the field. I am also hopeful that non-specialists will also make contributions. I am hopeful this discussion can follow the "Nullius in verba" motto adopted in 1660 by the Royal Society of London. A rough translation is "no word is final." (Better translations will be appreciated.) Here I present a brief review of my ozone and UV-B measurement program. Later I will present some reviews of the literature. As time permits, I will try to respond to questions and criticisms. First, like Robert Parson, who has written a nice series of faqs on ozone, let me state that I entered this field as an amateur. This is not unusual, as there are apparently no degrees for the measurement of ozone. I have learned that anyone with some basic experience designing opto-electronic circuits can design and make instruments that measure total ozone, UV-B and atmospheric aerosols. I have published plans for such instruments in SCIENTIFIC AMERICAN (August 1990), SCIENCE PROBE (several issues) and in several Radio Shack books. I have also learned that anyone with a basic knowledge of statistics and a personal computer can evaluate ozone trends. I come to the table with no agenda other than accurate and objective scientific measurements. The continuation of my measurement program is completely unaffected by any outside support which may cease should my findings not be as expected. In 1988 I began a program to measure total ozone, UV-B (total, diffuse and direct Sun), aerosol optical thickness (AOT), depth and column water vapor. This work has resulted in a 6-year data base of total ozone, AOT, column water vapor and direct UV-B. I also have a 2-year data base of total, direct and diffuse UV-B. My only sources of funding for this work, aside from substantial personal funds, are a 1993 Rolex Award, two small grants from Informedia, a PR company that publishes a UV newsletter for TV weathercasters, and a NASA contract to make measurements in Brazil in 1995. Any royalties I will receive from the sale of MicroTOPS ozonometers will be in the form of additional instrumentation for the Sun Photometer Atmospheric Network (SPAN). While I hope to some day expand SPAN with outside funding, I will never accept support from any organization that does not support totally independent and objective collection and analysis of data. For this reason, I recently rejected offers of support from a company that hopes to move a medical waste incinerator near my site. My early ozone measurements (1990-1993) were based on a calibration against NASA's Nimbus-7/TOMS conducted during the fall of 1990. This comparison enabled me to find an extrapolated calibration drift in NASA's Nimbus-7/TOMS beginning in the fall of 1991 and through August 1992. Although NASA rejected (politely, I might add) the apparent drift, they were unable to perform a calibration check themselves due to a drift in the Nimbus orbit that blocked the direct Sun. In August 1992, Dobson-83 measurements from MLO confirmed the drift, and in November 1992 NASA informed me by fax and telephone that my earlier concern about the drift was warranted. I published this work as "Satellite Ozone Monitoring Error," Nature, 361, 291, 1993. Since early 1994, my ozone measurements are based on a comparison of my best instrument (SuperTOPS, filter bandpass of 2.2 nm; band spacing of 5 nm; 2 degree field of view; virtually simultaneous observations of multiple wavelengths; direct download to hand-held computer for quick ozone determination) with Dobson-83, the world standard ozone instrument, at Mauna Loa Observatory (MLO), Hawaii. (Although NOAA provides Dobson-83 data, NOAA does not necessarily support or endorse this comparison.) There was no measurable drift in my principle ozonometer calibration between the 1994 and 1995 tests at MLO. I began measuring ozone in 1989, and the ozone at my principle site has declined significantly since then. For example: In the summer of 1993 I measured record low summer ozone at my site and corresponding increases in UV-B. This event was caused by an unusual intrusion of tropical air over Texas. Although a paper on this finding was approved by two peer reviewers, Science rejected the paper. The paper was then published as "Increased solar ultraviolet-B associated with record low ozone over Texas" by Forrest M. Mims III, SPAN, and Judson W. Ladd and Robert A. Blaha, National Weather Service. Last November, I measured record low ozone amounts at my site. These measurements were soon confirmed at the 1% level by NASA's Meteor-3/TOMS, NOAA's TOVs and by ground observations by EPA Brewer spectrophotometers in Georgia, North Carolina and Washington, DC. They were reported in "Unusually Low Ozone Detected Over South-Central U.S." by Forrest M. Mims III, SPAN, William F. Barnard, EPA, Arthur C. Neuendorffer, NESDIS Satellite Research Laboratory (NOAA) and Gordon J. Labow, Hughes STX (GSFC). As in the previous paper, this unusual ozone event followed an unusual movement of tropical air over the SE U.S. (The tropical stratosphere ordinarily holds less column ozone than at mid-latitudes.) Although ozone during the summer of 1995 was lower than during summer 1994, there has been a very significant increase in ozone at my Texas site since October 1995. Indeed, a preliminary study shows that ozone measured so far this winter exceeds that measured during this same time interval since satellite measurements were begun in 1978. What is particularly interesting is that winter values have already matched or exceeded spring maximum values during 1994-5. (Details will be reported in a forthcoming paper.) This recent finding illustrates the variability of ozone--and the need for the scientific community and interested observers to retain a traditionally skeptical scientific view. These views are my own. SPAN is a global network of volunteer observers who measure total ozone, UV-B, AOT and column water vapor from Paraguay, Togo, Falkland Islands, 4 Pacific islands, California, Colorado and Texas (with South Africa and other sites soon to be added). Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Ozone and UV-B Science Date: 8 Jan 1996 21:50:07 -0500 Brief reviews of representative peer- reviewed publications that demonstrate the importance of maintaining an objective perspective when considering the current state of the ozone layer: 1. World Meteorological Organization, "Scientific Assessment of Ozone Depletion: 1994," Report No. 37, 1995. Must reading. This report illustrates both the strengths and weaknesses of the prevailing ozone depletion paradigm. Excellent and thorough discussion of atmospheric chemistry. But coverage of meteorological influences on ozone is inadequate, as is the discussion of how trends are computed. The section on ultraviolet is only 22 pages of this 578-page document. The discussion of accuracy problems with the M-124 ozonometer, used in 1/3 of the ground-based ozone network, is inadequate. If the report discusses the measured ozone increases in the 1960's and the measured ozone decline following the eruption of Katmai, I missed both. (Katmai erupted in 1912. The ozone decline that followed was described by Gotz and is also detectable in Chappuis band ozone measurements made at Mt. Wilson, California, by the Smithsonian Astrophysical Observatory.) An important caveat: The WMO and others have stated or implied that this report is a consensus document, but this is misleading since the contributors and reviewers were apparently asked to pass only on specific areas of the report and not the entire document. The first contributor I called stated he had not even seen the complete report. 2. Komhyr, W. D., S. J. Oltmans, R. D. Grass, and R. K. Leonard, "Possible influence of long-term sea surface temperature anomalies in the tropical Pacific on global ozone," Canadian J. of Physics, 65, 1093-1102, 1991. When submitted to more prominent journals, this paper was apparently rejected by peer reviewers more knowledgeable of atmospheric chemistry than meteorology. Nevertheless, the paper presents a convincing case that long-term climatological change may have a very significant impact on the ozone layer and, specifically, the annual Antarctic ozone minimum popularly known as the ozone hole. 3. Henriksen, K. T. Svenoe and S. H. H. Larsen, "On the stability of the ozone layer at Tromso," J. of Atmos. Terr. Phys., 54, 1113-1117, 1992. The essential claim of this paper is that there is no significant long term change in the ozone layer above Tromso. The paper is carefully written and based on data acquired using an instrument with a good calibration record. 4. Henriksen, K. T., E. I. Terez, G. A. Terez, V. Roldugin, T. Svenoe and S. H. H. Larsen, "On the stationarity of the ozone layer in Norway and U.S.S.R.," J. Atmos. Terr. Phys., 55, 145-154, 1993. This paper follows the theme of (3) but for a significantly expanded geographic region. 5. DeMuer, D. and H. DeBacker, "Revision of 20 years of Dobson total ozone data at Uccle (Belgium): Fictitious Dobson total ozone trends induced by sulphur dioxide trends," J. Geophys. Res., 97, 5921-5937, 1992. This paper, which is discussed in (1), has raised concern about possible contamination of ground- based data elsewhere. The 1994 assessment (1) discusses this issue on p. 1.7 and concludes that the maximum error due to SO2 at Toronto, the most polluted site in Canada, is about 1% "in the early part of the record." The 1994 assessment concludes, "Work still needs to be done to assess the impact of SO2 on O3 measurements at many individual stations." Surprisingly, the 1994 assessment does not show nor does it even cite any of the published regional or northern hemisphere SO2 maps, which show very significant SO2 pollution over vast regions of Eurasia and North America. 6. DeMuer, D. and H. DeBacker, "Influence of sulphur dioxide trends on Dobson measurements and on electrochemical ozone soundings," Proc. of the Soc. of Photo-Optical Instrumentation Engineers, 2047, 33, 18-26, 1993. See review of (5) above. 7. DeMuer, D. and H. DeBacker, "Trend analysis of 25 years of regular ozone soundings at Uccle (Belgium), Abstract, EUROTRAC Meeting, Garmisch- Partenkirchen, April 1994. See review of (5) above. 8. Henriksen K. and V. Roldugin, "Total Ozone Variations in Middle Asia and Dynamic Meteorological Processes in the Atmosphere," Geophysical Research Letters, 22, 23, 3219-3222, 1 Dec 1995. This recent paper, which is based on ground-based data from several sites, claims that the current ozone paradigm is excessively influenced by atmospheric chemistry and that the role of dynamical processes is vastly underrated. The paper uses the provocative phrase "so-called 'ozone depletion'." 9. W. D. Komhyr, R. D. Grass and G. Slocum, "Total Ozone Increase over North America During the 1960's," Pure and Applied Geophysics, 106-108, 981-999, 1973. According to various international papers, there was a significant increase in total ozone during the 1960's. (If this is discussed in the 1994 assessment (1), I did not notice.) Walter Komhyr, one of the world's leading experts on the ground- based measurement of total ozone, wrote at least two such papers, which are included here because of Kohmyr's reputation and because of their very careful presentation and analysis of the data. Also, Kohmyr used only data based on a calibration obtained "...on very clear half-days when the ozone amount was believed to remain nearly steady...." The following trends during all or part of the 1960's are from Table 3 (p. 998): Tallahassee: +4.7% (+/- 1.3) Nashville: +8.8% (+/- 0.7) Boulder: +4,4% (+/- 1.3) Bedford: +5.3% (+/- 1.3) Toronto: +2.7% (+/- 0.9) Green Bay: +2.0% (+/- 1.2) Caribou: +5.9% (+/- 0.9) Goose Bay: +4.4% (+/- 1.1) Bismarck: +6.9% (+/- 1.1) Edmonton: +5.1% (+/- 1.0) The mean increase in ozone for these stations matches or slightly exceeds the mean decline in ozone given in the 1994 ozone assessment. The decline since the mid-1980's has been influenced significantly by the annual Antarctic ozone minimum. (The change in ozone absorption coefficients used in this paper (Vigroux) to the new values (Bass-Paur) will affect absolute values by about 5% but should not affect these trends.) 10. W. D. Komhyr, E. W. Barrett, G. Slocum and H. K. Weickmass, "Atmospheric Total Ozone Increase during the 1960's," Nature, 232, 390, 1971. See (9) above. These reviews are my own and do not necessarily represent the views of SPAN or its network of observers. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN From: fmims@aol.com (FMims) Newsgroups: sci.energy,sci.environment,talk.environment Subject: Re: CFCs in the atmosphere (was Re: Why do the green movement dislike nuclear power? Date: 8 Jan 1996 22:13:38 -0500 Len Evens writes (in part): >Mims himself has indicated from his personal experiments >various complex effects, and it would be helpful if others would >repeat these experiments or do other related experiments which would >put his work in perspective. Actually, my ozone measurements are original only for my sites. My cloud studies showing increased UV are based on phenomena that are well known by practitioners but simply not very widely published. My papers on record low ozone have been corrobrated by others. Please see my discussion of this on the new thread "Ozone and UV-B Science." >However, despite all this, there is no doubt today that CFCs have >been established as a very significant cause of ozone depletion. >If Forrest Mims disagrees that this has been established he should >say so. I have discussed this matter in great detail on this and other threads. Please see the new thread "Ozone and UV-B Science." >And if so he should explain why his opinion is worth more than >that of the vast majority of atmospheric chemists and other scientists >who have studied this question, who appear to say otherwise. By this I hope Len Evens does not wish me to base my views on scientific matters on majority vote. Paradigms can be very useful, but ozone science is much too young to be a paradigm. I do hope that Len Evens will review some of the scientific publications I have reviewed in the thread "Ozone and UV-B Science" that come to different conclusions than the WMO 1994 Assessment. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Ozone and UV-B Science Date: 10 Jan 1996 01:54:39 -0500 Robert Parson (rparson@spot.Colorado.EDU) responded to some of my recent comments on the WMO ozone assessment: >OK, I'll begin by responding to your comments on >the 1994 WMO Assessment. >>While the WMO assessment is an excellent >>reference, it is incomplete. >It is necessary to realize that the WMO >assessments are incremental, >rather than cumulative; the 1994 assessment >concentrates on developments since 1991. Some of >the incompleteness may be due to this. Yes, but those who are unaware of its incremental status have referred to it as an absolutist statement. For example, EPA web pages on ozone and bromine both agree to update their contents with new scientific findings. Yet when I recently suggested the addition of a citation of an important new finding re. bromine (published in a peer-reviewed paper), both web pages promptly rejected my suggestion since it was not, in their view, a consensus statement. (I am glad to report that the bromine page relented and did update some of its contents.) >>1. It fails to adequately discuss the derivation >>of trends from ground-based data. (I am unaware >>of any publications in the peer-reviewed >>literature that describe how ozone time series >>are corrected and the criteria for rejecting and >>accepting data from specific instruments. If >>such publications are available, I will be most >>grateful to receive their citations.) >There are fairly extensive discussions of the >procedures in the 1989 Assessment (Report #20) >and the 1988 Assessment (Report #18). For primary >sources I would consult the papers of Rumen >Bojkov and his collaborators, e.g. "A statistical >trend analysis of revised Dobson total ozone data >over the northern hemisphere", J.G.R. _95_, 9785, >1990. I don't know if they contain sufficient >detail for your purposes; on this subject >your expertise far exceeds my own. But all your citations were published prior to the 1992 Quadrennial Ozone Symposium, which I attended and where Rumen Bojkov hosted a meeting, which I also attended, on the urgency to reprocess ground- based data. Since not all ground data have been reprocessed even today, and since there is controversy over the reprocessing procedure, concerns that have been expressed about the validity of trends of ground-based data remain valid. I also (again) point out that Bojkov uses M-124 data (1/3 of the ground-based network) in WMO trend studies. The significant errors of this instrument (caused primarily by its aerosol and air mass dependence and also by the time required to make an observation) may not seriously affect trend studies if the errors can be viewed as a known offset. However, since there are so many variables in M-124 observations (e.g. time of day. presence of aerosols, cloud fragments or variable haze at the sun, etc.) how does one establish a consistent criteria for which M-124 data are usable in trend studies? If the procedure has been published in detail, I am unaware of it and will be appreciative of receiving a citation. >>6. It fails to adequately discuss significant >>changes in climatology and increases in methane, >>either of which may lead to significant ozone >>reductions in polar regions. >I have read speculations that increasing methane >concentrations may, by increasing stratospheric >water vapor, contribute to polar stratospheric >cloud formation and thus to enhanced polar ozone >loss. However I haven't seen much in the way of >actual research on the subject. James Lovelock discusses in his book "Healing Gaia" a possible role for increased methane in establishing the Antartic ozone minima. It was Lovelock who first discovered the ubiquous presence of CFCs in the atmosphere between England and Antarctica. He also discovered the presence of natural methyl chloride and methyl iodide, both ozone depleters. Research on the role of methane in psc formation costs money, and in ozone research the vast majority of the funds have gone to CFC studies. Even the stratospheric amounts and trends of methyl chloride, methyl bromide methyl iodide are inadequately known, since the research community decided from the outset that CFCs were more important. (Of course measured global trends of UV-B are not known either, since nearly all the money in this field goes to measuring ozone and the factors which afffect it.) >>7. It's discussion of the sulfur dioxide >>contamination at Uccle, Belgium, does not >>provide references for its conclusion that such >>pollution is highly localized at Uccle when, in >>fact, several widely available publications >>describe significant sulfur dioxide and/or >>sulfate pollution over substantial regions of >>Europe, Eurasia and North America. >What is important for the ozone trends is not so >much the absolute amounts of SO2 pollution, but >the _changes_ in those amounts. At Uccle, surface >SO2 changed by a factor of 5 over the period >1972-1991. Have you consulted the Mylona et al. >reference that they give (I have not)? >One thing I noted in the first DeMuer-DeBacker >paper was that the contaminated Dobson trend was >_larger_ (more negative) than the >TOMS trend for the same region, over the period >where the comparison can be made. Most of the >time Dobson trends are somewhat smaller than >TOMS trends; this has been ascribed to differing >sensitivity to tropospheric ozone. When the SO2 >contamination is accounted for, the Dobson trend >and the TOMS trend agree better. This suggests to >me that there is indeed something special about >Uccle. But even the 1994 assessment specifically states that the SO2 data contamination problem requires further study--which is what De Muer and De Backer have claimed in their papers. I recently queried Rumen Bojkov about this very issue. He responded along the lines of the 1994 assessment and informed me that he used the Uccle data as submitted by the Belgians (i.e. with the SO2 effect subtracted). Of course you are correct that it is the change in SO2 that matters. While Uccle did have a significant SO2 problem, it is important to understand that SO2 lingers a while before combining with water vapor to become H2SO4 and other byproducts. In short, SO2 problem at Uccle must be considered a regional, not merely local, phenomenon. During the summer of 1995, an EPA Brewer spectrophotometer was at my site for 62 days. It daily measured a total column SO2 abundance of several Dobson units or more (once 16 DU!) which originated from points hundreds of kilometers away (paper in preparation). I even detected sulfate haze that apparently originated from the TVA region, drifted south over the central Gulf of Mexico (where I observed it on 8 Sept while flying from Brazil to Dallas), and then circulated up over Texas. [remainder of this response to be posted...] Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Ozone and UV-B Science Date: 10 Jan 1996 02:00:28 -0500 Robert Parson (rparson@spot.Colorado.EDU) responded to some of my recent comments on the WMO ozone assessment. I responded to the first half of his response in a prior post. Here is the remainder of my response: >>8. It devotes little space to the naturally >>occurring fraction of such ozone depleting gases >>as methyl chloride, methyl bromide and methyl >>iodide (all the latter, a "significant" ozone >>depleter, is believed to be natural in origin). >There is an entire chapter devoted to methyl >bromide. As for methyl iodide as a contributor to >ozone depletion, that is a recent speculation >which post-dates the writing of the WMO report - >the executive summary was written in August 1994, >and the various chapters were written before >that. The methyl bromide chapter, which is longer than the tiny UV chapter, devotes, about 2 pages to naturally occurring methyl bromide sources, which, as I stated, means the assessment "devotes little space to the naturally occurring fraction of" this and other natural ozone depleters. My interest in this topic was raised last summer when I flew for hours through and over smoke from biomass burning in Brazil. As you know, biomass burning is a significant source of methyl chloride and methyl bromide. In my opinion it is important to quickly establish a means for monitoring the stratospheric burden of these gases. >The methyl iodide papers appeared in the Fall of >1994. Yes, and at least two methyl iodide papers are cited in the 1994 assessment. Susan Solomon's paper in JGR (99, 20491-20499, 1994) is discussed on p. 4.16. >>While the WMO and various other groups have >>depicted the 1995 assessment as a consensus >>document, it apparently is not. It is simply a >>selective review and discussion of some of the >>peer-reviewed literature. I discussed this >>with a leading scientist listed as a >>contributor, who >>stated he had not even seen a copy of the report >>(beyond his contribution). >The WMO reports are as comprehensive a review of >the literature as >exist anywhere, and the people who I have spoken >to around here do consider them to represent a >consensus. It will inevitably be the case >that some of the contributors will disagree with >the conclusions that the lead authors of the >chapters draw, since there will never be >universal agreement on any scientific subject >that is still a topic of active research. >Nevertheless the chapters are written by leading >researchers in each area and peer-reviewed by >others, and the authors rotate from one >assessment to the next. People who are seriously >interested in the subject should not, of course, >stop at the WMO assessments but should dig up the >papers cited therein (as Forrest Mims has.) While I appreciate the importance of consensus science, there are simply too many papers that raise important questions about trend analysis and overlooked dynamical processes judged less important than anthropogenic chlorine and bromine by many in the atmopsheric chemistry community-- who clearly have dominated the WMO assessments. I could site a dozen instances where consensus science which later proved to be in error delayed important research. I'll just cite one: For many years the consensus science of the USGS was that Arizona's Barringer crater was volcanic. Barringer spent 25 years trying to prove the crater was formed by a meteorite. Although he was criticized severely, he was eventually proved right. (I once found bits of meteorite, one the size of a pea, in ant hills at the bottom of the crater.) I am well aware of ongoing, significant ozone changes from considerably personal experience measuring them. If the scientific community is seriously concerned that ozone depletion presents a bonafide threat to life on Earth, then it would have long ago established a coordinated, international solar UV-B observing network using compatible instruments. Although leading scientists have called for the establishment of such a network for more than 20 years, the scientific community has yet to establish one. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Ozone and UV-B Science Date: 11 Jan 1996 21:12:34 -0500 Joshua Halpern (jbh@haven.ios.com) responded to my comments on "Scientific Assessment of Ozone Depletion: 1994. I appreciate his response and look forward to his response to my post re. his request for citations about the well documented, significant rise of ozone during the 1960's which I have not yet found reference to in the 1994 assessment: >:FMims (fmims@aol.com) wrote: >: Joshua Halpern (jbh@haven.ios.com), responding >to >: Andrew Russell (arussell@bix.com) on another >: thread, made various comments about ozone.... [cut] >: Halpern suggested: >: >See the WMO Scientific Assessment of >: Stratospheric Ozone 1995 >: While the WMO assessment is an excellent >: reference, it is incomplete. Here are several >: problems I noted while scanning this 550+ page >: document: >Well, you have to read all the references too! >Seriously, this seemed the best place to start >and you are really nigling below. See below... >: 1. It fails to adequately discuss the derivation >: of trends from ground-based data. (I am unaware of >: any publications in the peer-reviewed literature >: that describe how ozone time series are corrected >: and the criteria for rejecting and accepting data >: from specific instruments. If such publications >: are available, I will be most grateful to receive >: their citations.)> >There is a long discussion of these issues in >the WMO 1989 reoirt in the global trends >section, with references to various >intercomparisons. You cite the 1989 report--which was old news when I attended the 1992 Quadrennial Ozone Symposium, and where Rumen Bojkov hosted a meeting, which I also attended, on the urgency to reprocess ground- based data. Since not all ground data have been reprocessed even today, and since there is controversy over the reprocessing procedure, concerns that have been expressed about the validity of trends of ground-based data are as remain as valid today as ever. This is a common topic of discussion among those who measure ozone. >: 2. It fails to adequately discuss significant >: limitations (described in the peer reviewed >: literature) of the M-124, the instrument which >: comprises 1/3 of the ground-based ozone network. >: The M-124 typically indicates too little ozone at >: high solar zenith angles (10-40 Dobson units >: typical) and significant error in the presence of >: aerosols (due to its large field of view and the >: wide bandpass of the filters--20 nm--and their >: wide spacing of 24 nm). M-124 data are completely >: unreliable when clouds fragments or variable >: density cloud haze cross the sun during >: observations. This is because the instrument >: observes only one channel at any time, and several >: seconds or more must be allowed for its mechanical >: meter movement to be checked for zero and to then >: settle before the second channel is measured. (I >: used an M-124 regularly for 2+ years and made >: Langley plots using it at Mauna Loa Observatory in >: Hawaii in 1992, 1993 and 1994. These limitations >: of the M-124 are well known, which explains why >: NASA and NOAA declined my offer of a free M-124. >Again, see the WMO 1989 report. Specifically, >references to intercomparisons with Dobsons >were given as Bojkov Ann Geophys 25 (1969)293 >and the 1980 and 83 WMO ozone reports for >comparisons after the filters in the M-83 >were improved in 73. Yes, the instrument was improved, but it retains a significant air mass and aerosol dependence. >As to the M-124, the report states:No trend data >with the M-124 can be expected for about a decade >unless the data can be satisfactorily cross >calibrated with the M-83 data from the same location. But I wrote about the 1994 report, and it does use M-124 data. See pp. 1.15-1.16, etc. >: 3. Its discussion of solar ultraviolet is much too >: brief (only 22 pages). >This is a SUMMARY report. Like I said, read the >references. Its not as if the stuff were >hidden. I have read the references. My point is that the tiny size of the UV section illustrates the well known lack of interest by the well financed ozone community in actually monitoring the UV about which they are so concerned. >: 4. It fails to provide any kind of cost-benefit >: analysis of ozone research. Nor does it include >: (unless I missed it) any summaries of money spent >: on ozone research. >Not the charge of the WMO. The WMO report is a >_Scientific Assessment of Stratospheric Ozone_ >Governmental organizations cannot go beyond >their assignment. Intergovernmental organizations >cannot even get that far. >This is a red herring. I completely disagree. Science should not be immune to presenting financial audits of its work. The U.N. and virtually all other governmental bodies do this frequently, as do corporations. Financial accounting is a well established means for evaluating the success of programs. Consider the TOMS ozone mapper aboard NASA's remarkable Nimbus-7 satellite, which lasted more than 14 years when it was expected to last only about 3. The taxpayers received a bargain for this major technlogical achievement, but I have yet to see any accounting that explains this. >: 5. It's discussion of volcanic effects on ozone is >: incomplete. [No response by Halpern.] This response will continue in a subsequent post. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Ozone and UV-B Science Date: 11 Jan 1996 21:12:36 -0500 Thanks to Joshua Halpern (jbh@haven.ios.com) for his response to my comments on "Scientific Assessment of Ozone Depletion: 1994." This is a continuation of my response: >: 6. It fails to adequately discuss significant >: changes in climatology and increases in methane, >: either of which may lead to significant ozone >: reductions in polar regions. [No response by Halpern.] >: 7. It's discussion of the sulfur dioxide >: contamination at Uccle, Belgium, does not provide >: references for its conclusion that such pollution >: is highly localized at Uccle when, in fact, >If you've ever been there, you know that Uccle >is special. Although much improved, it was in >its time like Gary, IN, Lackawana, NY and other >garden spots of pollution. If anecdotal accounts are acceptable, then you would have observed even worse pollution in parts of Eastern Europe. Also, it's important to realize that SO2 does not immediately sulfate. It has a finite lifetime, and is therefore a major regional problem. (See below.) >: several widely available publications describe >: significant sulfur dioxide and/or sulfate >: pollution over substantial regions of Europe, >: Eurasia and North America. >You are folding together a few orders of magnitude >here. Can you provide a citation? Last summer a Brewer spectrophotometer at my Seguin, Texas, site measured SO2 levels of from several to as much as 16 Dobson units each day. Weather patterns show that some of this SO2 apparently drifted from as far as the TVA. >: (The Uccle group has >: published papers claiming that ozone decline at >: their site and possibly elsewhere is "fictitious." >: They attribute the apparent decline to a reduction >: of sulfur dioxide as sulfur dioxide pollution has >: been reduced. The UV absorption bands of sulfur >: dioxide overlay those of ozone, and, therefore, >: the presence of SO2 can cause an apparent, not >: real, increase in ozone.) >: 8. It devotes little space to the naturally >: occurring fraction of such ozone depleting gases >: as methyl chloride, methyl bromide and methyl >: iodide (all the latter, a "significant" ozone >: depleter, is believed to be natural in origin). >Again, you want an encylopedia, write an >encyclopedia. Or are you saying that the >role of the methyl halides has not been >properly treated, in the measurements, models, >and depletion potential work. As with the tiny UV chapter, my point is that we simply know little about the stratospheric amount, distribution and trends of naturally occurring methyl chloride, methyl bromide and methyl iodide. The 2 pages devoted to naturally occurring methyl bromide (vs. hundreds for CFCs) illustrates my point. As I wrote Robert Parson, my interest in natural ozone depleters was raised last summer when I flew for hours through and over smoke from biomass burning in Brazil. As you know, biomass burning is a significant source of methyl chloride and methyl bromide. In my opinion, it is important to quickly establish a means for monitoring the stratospheric burden of these gases. >Further, as in the CO2 debate, no one is >saying that the man made depletion is the >only depletion mechanism, but we are saying >that the man made depletion is having a >significant effect on the atmosphere But this is simply not the slant of the 1994 assessment and the various "sky is falling" press releases that have come from the WMO and other organizations. If the scientific community seriously believes that increased UV-B resulting from ozone depletion poses a serious threat to life on Earth, then it is irresponsible for it not to have established a coordinated, international network of compatible instruments to measure that threat. The cost of such a network would be a small fraction of the enormous sums already spent on satellites, polar expeditions, cruises and conferences to study CFCs. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.physics,sci.environment,sci.geo.meteorology,sci.chem Subject: Re: Ozone layer/Dobson Units Date: 12 Jan 1996 02:00:09 -0500 Amy Hansen (ahansen@sisnet.ssku.k12.ca.us) asked: >I have tried to research what a dobson unit is but haven't been able to find >anything. Does anyone know? >I was also wanting to know more information about the ozone and how it is >affected by the seasons. If anyone can help me I would greatly appreciate >it. At standard temperature and pressure (i.e. at the Earth's surface on a pleasant spring day) 100 Dobson units (DU) of ozone would equal a layer of ozone 1 mm thick. The average amount of ozone around the Earth is about 300 DU (or 3 mm) at STP). Ozone peaks in the spring and reaches a minimum in the early winter. For my site, typical peaks in May are 350 DU while typical minimums in December are 240 nm. The records here are 460 DU (16 Mar 1990) and 220 DU (17 Nov 95). Last winter, ozone was recond low at my site. This winter it is record high, with one day at 340 DU. Today was 303 DU. Forrest M. Mims III Sun Photometer Atmiospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Ozone and UV-B Science Date: 12 Jan 1996 10:25:16 -0500 Rich Puchalsky (richp@upx.net) wrote: >Robert Parson (rparson@spot.Colorado.EDU) wrote: >:Forrest Mims' comments, unlike nearly all of >:the examples of "ozone skepticism" that I have >:seen in newsgroups and elsewhere, >:are based upon a thorough study of the >:underlying science. I urge sci.env readers not >:to respond in a knee-jerk fashion, but to >:consider his points seriously. >It is good to see some intelligent criticism by a >real scientist rather than the usual >Limbaugh-inspired nonsense. Although I tend to >think that Mims over-emphasizes the political >aspect of science funding in relation >to a ground-based UV monitoring project, I'm glad >to see that he's elevating the level of >scientific discussion here. I appreciate receiving Rich Puchalsky's (and Robert Parson's) comments. Puchalsky has a valid point if he feels I have over-emphasized the political aspect of the lack of UV funding. This may trace from my input to the discussions some time back over the firing of William Happer from the Department of Energy over his outspoken views on the need for a UV network and related matters. A more accurate view of this matter is that the scientific community has simply failed to recognize the vital importance of measuring UV-B. While a few billion dollars or more were going to ozone research, very little was going to actually measure the hypothetically higher UV levels that inspired the ozone research. Now, as so lucidly pointed out by Sasha Madronich of NCAR and various other scientists who advocate the measurement of UV-B, we simply have no baseline with which to compare contemporary measurements of UV-B. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: talk.environment,sci.environment,sci.energy Subject: Re: CFCs (was: Why do the green movement dislike nuclear) Date: 13 Jan 1996 10:48:43 -0500 James Hammerton (james@tardis.ed.ac.u) wrote about the supposedly minimal effect of volcanic emissions on the ozone layer. Time prevents a more detailed response now (and I have addressed this matter earlier). But I wish to point out the following: 1. The latest American Geophysical Union publication on Mount Erebus specifically states that the possibility of Erebus (which is continuously active in a very dry, high-altitude environment) contributions to the Antarctic ozone hole should not be ruled out until further studies are conducted. 2. Published data from the Smithsonian Astrophysical Observatory observations at Mount Wilson showed signficant depletion of ozone following the eruption of Katmai in 1912, long before the development of CFCs. This was addressed by Dobson's collaborator Gotz in two publications and the decline can be seen in a publication by R. Roosen. Hammerton also discussed the anthropogenic nature of CFCs. It is interesting to note that published papers have shown a very significant presence of CFCs during forest fires. This is apparently because CFCs become trapped in wood as a byproduct of the respiration of these plants. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Ozone and UV-B Science Date: 15 Jan 1996 00:58:40 -0500 Joshua Halpern (jbh@haven.ios.com) wrote (in part): FMims (fmims@aol.com) wrote: [cut...] >: I appreciate his response and >: look forward to his response to my post re. his >: request for citations about the well documented, >: significant rise of ozone during the 1960's which >Just as soon as you respond to my original point >(made in response to Russell's post) that if >you claim UV-B is constant, in light of the >over twenty year Dobson record showing increased >flux below 320 nm relative to the flux above 320 nm, >you must admit that there is less absolute light >intensity above 320 nm. A very worrying prospect. In view of my publications on measurements of significant increases in UV-B, I do not understand why you believe that I have claimed UV-B has remained constant. Please explain. >Well, you did get me to the library, but the papers >are sitting on my desk at work. With just a little >bit of digging, I have the following questions about >Komhyr's work: (all based on stuff that I found >in twenty minutes walking thru the library. References >provided later) >Actually, let me add a caveat. Komhyr is an >excellent scientist. Clearly among the very best in the field. >My questions arise because >we are asking 1996 questions about 1970's data >and interpretations But the instrument remains identical (ca. 1926 with later addition of an electro-optical detector means). Many of the Dobson's in Komhyr's paper are still in use today. Only the ozone absorption coefficients have been changed. (Formerly Vigroux; now Bass-Paur. This changes the absolute amount of ozone by about 5%--but has no effect on trends.) >Why do the annual maxima show an increase and not the >minima? Komhyr doesn't say, but I offer this: Ozone minima in the northern hemisphere occur in early winter. With some occasional exceptions in post-Pinatubo years, the lowest ozone almost always accompanies intrusions of tropical air. Since nearly all studies show no significant trends for tropical ozone, the minima would be relatively stable from year to year. >Is a simple annual averaging of the data >as Komhyr did, an appropriate method, or is >a more sophisticated time series analysis appropriate? This question is at the core of ozone trend studies. The latest trend study (must reading) was just published: Rumen D. Bojkov, Lane Bishop & Vitali E. Fioletov, "Total ozone trends from quality-controlled ground-based data (1964-1994)," J. of Geophys. Research 100, D12, 25,867-25,876, 20 Dec 1995. Statistical filters have been applied to the time series to remove solar cycle and QBO effects. (This was evidently not done by Komhyr.) A hockey stick analysis was then applied, evidently mean data from 1964-70 being the baseline, and a linear trend fit applied to 1970- 94. The results are presented for 46 Dobson stations and, with some M-83/M-124 data, for 4 major geographic regions. Overall, this paper, which is an expanded account of information in the 1994 WMO assessment, ranks among the very best yet published. However, the report raises some important new questions: 1. The hockey stick analysis uses 1970 as the breakpoint "...to be sensitive to a possible effect of chlorofluorocarbons on total ozone, which photochemical models predict to be minimal before 1970." But the 1964-70 period is far to brief to serve as a baseline for a climatological trend study, especially since there were very significant ozone fluctuations during this period. For example, Fig. 1 (p. 25,870) shows a very substantial increase in ozone over Europe (>8%) from 1964 to 1970. Quality pre-1964 data were available for 3 of the 4 regions but were not used (see below). 2. The report includes no data prior to 1964 "since before 1964 a sufficiently dense set of stations was operating only in Europe, Japan, and Australia." (p. 25,868.) Yet the only other region summarized in Fig. 1 is "North America," and quality ozone data were collected in North America before 1964 (see Komhyr's paper). But even ignoring the North American data, it is puzzling why pre-1964 data from the three other regions were not included, especially since the baseline time series for the hockey stick anaysis is so brief, and because Komhyr and others described such a significant rise in ozone during the 1960's. 3. All 4 regional trend plots in Fig. 1 show great variability but no obviously significant trends prior to the El Chichon-Pinatubo era. Perhaps the trends need to be rexamined in light of the various known and hypothesized volcanic effects. It appears that a hockey stick analysis using 1964 to 1981 as the base would provide a different result and would show a powerful correlation of ozone decline and volcanic activity (the ozone destruction caused by SO2 aerosols being enhanced by the presence of Cl). I will query Rumen Bojkov about these and other points in this paper--which, imo, surpasses all previous efforts. >If you extend the data record Komhyr used to a >longer time period (up to the present), is >the trend he observed still statistically >significant for the 1960-1969 time period? >Was the data Komhyr used ever reanalyzed with >corrections for SO2 and NO2 interferences >and corrections for revised ozone absorption >cross-sections >Was the data Komhyr used ever reanalyzed with >corrections for nuclear test effect? I don't know. Some published references show nuclear tests may have had some effects; others say no. (cut...) : >:FMims (fmims@aol.com) wrote: : >: Joshua Halpern (jbh@haven.ios.com), responding : >to : >: Andrew Russell (arussell@bix.com) (delete previous, lenthy exchanges re. WMO report...) : You cite the 1989 report--which was old news when : I attended the 1992 Quadrennial Ozone Symposium, : and where Rumen Bojkov hosted a meeting, which I : also attended, on the urgency to reprocess ground- : based data. >Once again, you are confounding two separate issues. >Again, were I mistrustful, I would assume this was >in an attempt to avoid admitting that your original >statement was false. My response was to a direct >challange from you to cite a source where these >problems were discussed. The 1989 WMO SASO and >references therein are such sources. Parson's cited >the same source in his response. Therefore your >implication, that this problem has been not even >commented on by the community ill taken. But I did not state of imply that the problem has "not even been commented on." Indeed, I wrote: >: >: It fails to adequately discuss the derivation >: >: of trends from ground-based data. >An additional point you now raise is that not all >ground based data has actually been >reprocessed. Correct. : Since not all ground data have been : reprocessed even today, and since there is : controversy over the reprocessing procedure, : concerns that have been expressed about the : validity of trends of ground-based data are as : remain as valid today as ever. This is a common : topic of discussion among those who measure ozone. >Again, this is an immature demand for perfection. >Significant parts of the data record have been >reprocessed, especially, the Dobson network and >even from the most reliable parts of the old M-83 >network (see the 1989 SASO which is the one I have >at home). Why were carefully processed data from many stations prior to 1970 not used in compiling the 1994 assessment? (See discussion of Rumen Bojkov's recent paper above.) As for Russian M-83 data, my comments on the serious deficiencies of this instrument have been previously posted. My comments were based on peer-reviewed publications and my extensive experience with the Russian M- 124, the improved successor to the M-83. >By the way, I note that as a result of 18 years of further >analysis, the rise noted by Komhyr in his 1971 analysis >has essentially disappeared (See figures2.2-1 and 2.2-2 >pp 197 in the 1989 report) Unless someone tells me why >here, I guess I have more library work ahead of me. See Bojkov's recent paper cited above. Even with 1964 as a start point, he shows an enormous increase in ozone (>8% in Fig. 1) over European stations during the 1960's. : >: 2. It fails to adequately discuss significant : >: limitations (described in the peer reviewed : >: literature) of the M-124, the instrument which : >: comprises 1/3 of the ground-based ozone network. >Well, this again is a red-herring. The number of >M-124s may be large, but they are known to >be less reliable than the Dobsons. Most analyses >that I have seen, at least initially separate >measurements with different types of instruments, >then discuss corss-calibration, and only in a last >step, if then, combine the data records from >different instruments. Use of an inferior instrument to establish trends having global implications a red herring? I suggest you speak with any professional ozone scientist about this. (Call me at 210-372-0548 and I'll give you some names.) As I posted earlier, when I asked the lead author of a major paper on ozone trends why M-83/M-124 data were used, he specifically stated "for political reasons." (By this he did not mean political conspiracy; one of his co-authors is a leading proponent of the M- 124.) Response to Halpern continues on subsequent post... Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Ozone and UV-B Science Date: 15 Jan 1996 01:11:34 -0500 This is part 2 of response to Joshua Halpern (jbh@haven.ios.com), who wrote (in part): >FMims (fmims@aol.com) wrote: (See part 1) : >: The M-124 typically indicates too little ozone at : >: high solar zenith angles (10-40 Dobson units : >: typical) and significant error in the presence of : >: aerosols (due to its large field of view and the : >: wide bandpass of the filters--20 nm--and their : >: wide spacing of 24 nm). >Wide bandpass would, however, decrease the falsifying >effect of SO2 interferences. Unlikely. See a plot of the highly structured, comb-like SO2 absorption spectrum, and you'll understand why. In any event, the aerosol, FOV and air mass dependence are so severe that they can cause errors of 40 Dobson units or more. : >: M-124 data are completely : >: unreliable when clouds fragments or variable : >: density cloud haze cross the sun during : >: observations. This is because the instrument : >: observes only one channel at any time, and several : >: seconds or more must be allowed for its mechanical : >: meter movement to be checked for zero and to then : >: settle before the second channel is measured. (I : >: used an M-124 regularly for 2+ years and made : >: Langley plots using it at Mauna Loa Observatory in : >: Hawaii in 1992, 1993 and 1994. These limitations : >: of the M-124 are well known, which explains why : >: NASA and NOAA declined my offer of a free M-124. >True, but all you are saying is that a Dobson is >better. The extent of the variable haze problem >is operator and weather dependent, and I assume that this >means that some M-124 sites will be better than others. >An implication of your statement is that one should >immediately replace any instrument which is in >any way inferior to the state of the art. This >is a terrible strategy for long term measurements. No. The Russians developed and perfected a filter ozonometer having characteristics virtually as good as the Dobson in the late 1960's, long before the M-83/M-124 became so firmly established. This instrument was described in the peer-reviewed literature (ref. sent on request), and it stimulated much of my own development of improved filter ozonometers. It is very unfortunate that this improved instrument was not used instead of the M-83/M-124. (The only reason I can think of is that the very narrow bandpass filters it used were much more expensive and difficult to make than the very wideband filters used in the M-83/M-124.) : >Again, see the WMO 1989 report. Specifically, : >references to intercomparisons with Dobsons : >were given as Bojkov Ann Geophys 25 (1969)293 : >and the 1980 and 83 WMO ozone reports for : >comparisons after the filters in the M-83 : >were improved in 73. : Yes, the instrument was improved, but it retains a significant : air mass and aerosol dependence. >Look, to someone who works with fairly high resolution >lasers, spectrometers and interferometers, Dobsons >ain't so hot either. The key Dobson wavelengths have a width of 1 nm, which is far superior to the 20 nm bandpass of the M-83/M-124. As for "lasers, spectrometers and interferometers," I, too, work with and have designed, built, tested and characterized all the above. But this work hasn't affected my ozone and UV-B work. >An obvious point of weakness >is the poor choice of measurement wavelengths >with respect to the somewhat structured absorption >of SO2, the lack of a wavelength at which neither SO2 >or NO2 absorb, etc. This is preciusely why the Brewer was developed. But for various reasons Brewer data do not appear in the 1994 WMO repoprt. (cut unimportant M-124 stuff...) >: >: 3. Its discussion of solar ultraviolet is much too >: >: brief (only 22 pages). (cut...) >:My point is that the tiny size of the >:UV section illustrates the well known lack of interest by the >:well financed ozone community in actually monitoring the UV >:about which they are so concerned. >My, is this special pleading for a GRANT???? I have no pending grant applications. (Although a few universities are now doing so based on proposed work with instruments I have developed.) I make a decent living writing books and articles about science, and, at this point in my career, I have no plans or desire to make money from doing science. (Disclaimer: NASA hired me to measure ozone, UV, etc. in Brazil during SCAR-B. All money above my expenses will go to my work with SPAN.) (cut rockets...) >With >respect to the ozone depletion, there are two >problems with ground level observations of UV. >a. If it is hard enough to do a set of relative >intensity measurements at a few wavelengths, then >it would be impossible to do measurements of >absolute intensity across 100 nm. My initial >impression is that doing a total intensity >measurement through a broad band filter is an >invitation to taking a lot of meaningless data, >subject to all types of falsification. Wrong. As discussed countless times in the photobiology literature, the effects of UV-B on living systems are broadband in nature. Thus a detector that models the spectral response of the action spectrum in question is an ideal approach. As for narrow spectrum vs. broadband measurements, for 62 days last summer I compared a 1-nm resolution Brewer spectrophotometer (courtesy of EPA and University of Georgia) with a broadband UV-B 501 Biometer (courtesy of Solar Light Company), various 2.2-, 5-and 8-nm UV-B detectors of my own design, a broadband UV-B Vital Technologies BW-10, and a broadband UV-B Sunsor. This work, which is now being prepared for publication, clearly shows very significant advantages of a broadband instrument such as the 501. For example, the Brewer requires 8 minutes to do a complete DUV scan, which means transitory clouds, changes in transparency and enhanced scattering from moving clouds can cause important errors. Other work has shown that integrating narrow-wavelength measurements of UV-B to arrive at a desired action spectrum is subject to a variety of errors. The principle advantage of narrowly resolved measurements of UV-B is the identification of various trace species, especially SO2. Recently published intercomparisons show agreement of very expensive scanning spectral radiometers is much too coarse for trend studies. >b. Measuring total UV, am I measuring the effects >of ozone depletion, local pollution or global >warming. How do I tear all of this apart. Perhaps you missed my many earlier posts on UV-B and aerosols. (I am not sure what you mean by global warming--increased clouds?). Smoke in Brazil reduced UV-B by 80% last August-September. Haze over Washington on 6 July 1994 reduced UV-B around 20% and caused 88% of the UV to be scattered from the sky. UV-B stations MUST measure the diffuse UV-B as well as the total sky UV-B to identify aerosol and cloud effects. I also recommend direct measurements of optical depth, total ozone, total water vapor and basic weather paramaters. (I have made such measurements for 6 years using homemade, very accurate instruments, some described in the peer-reviewed literature.) Unfortunately, only a tiny number of stations do all this. (The result is an absolutely major gap in the data base for an era when a few billion dollars have been spent on studying the ozone problem--hence my concern about cost-benefit analysis of ozone research.) >: >: 4. It fails to provide any kind of cost-benefit >: >: analysis of ozone research. Nor does it include >: >: (unless I missed it) any summaries of money spent >: >: on ozone research. (cut details...) >: >This is a red herring. >: I completely disagree. Science should not be >: immune to presenting financial audits of its work. (cut remainder of my response...) >An even redder herring. (cut stuff about budgeting...) I still disagree. In the face of increasing scrutiny (and skepticism) from those who provide their funding, scientists would do well to include a few pie charts of where the money goes, especially in such widely cited summary reports as the WMO assessments. (cut Nimbus-7...) >: >: 5. It's discussion of volcanic effects on ozone >: >is incomplete. >: [No response by Halpern.] >Basically, if I had bothered, the response would be >the same as Parson's. It was discussed. It was discussed >previously in other SASO reports, the SASO reports are >incremental, the SASO reports are not encyclopedias, etc. There is a need for more studty of the effects of volcanoes on ozone. (During the Pinatubo era I often observed that high optical depth caused by volcanic aerosols was accompanied by reduced ozone. Balloon measurements by various others showed the same.) To my knowledge, previous reports and Parson's (excellent) faq do not include: 1. Publications by ozone pioneer (and co-worker with Gordon Dobson) Paul Gotz describe significant total ozone decline following the eruption of Katmai, a major SO2 emitter, in 1912. (See also the outstanding papers by Robert Roosen on the early Smithsonian work, one of which shows low ozone in 1912). This work was based on careful spectral observations from Mt. Wilson and possibly Algeria by the Smithsonian Astrophysical Observatory. (See, for example, F. W. Paul Gotz, "Ozone in the Atmosphere" in "Compendium of Meteorology, ed. T. F. Malone, 275-291, 1951, for brief mention of "very slight ozone amount during the year 1912" on p. 280 and specific references.) 2. With regard to the relationhip, if any, of emissions from Mt. Erebus and the annual spring ozone minimum over Antarctica, Philip R. Kyle wrote in his preface to "Volcanological and Environmental Studies of Mount Erebus, Antarctica" (Antarctic Research Series, Vol. 66, 1995): "Such speculation is not supported by current observations made at Mount Erebus, but it is important that the scientific community not dismiss the idea out of hand without making the appropriate scientific observations and evaluations." The same could be said about other ozone paradigms. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: HR 475, More Freon = Less Ozone Date: 15 Jan 1996 01:26:30 -0500 Joshua Halpern wrote about ozone: >Total mid latitude depletion appears to be >over ten percent since 1960. I am unaware of any paper or study that makes this claim. Can you please provide your source? Forrest M. Mims III Sun Photometer Atmospheric network (SPAN From: fmims@aol.com (FMims) Newsgroups: sci.bio.ecology,sci.environment,alt.catastrophism Subject: Re: Safe places in ozone depletion?? Date: 18 Jan 1996 21:33:55 -0500 Jeffrey Levy wrote (in part): >Ozone depletion of 10% in Winter and 5% in Summer has been >measured over most of the US. A measured ozone increase of from 5 to 11 % (location dependent) occurred during the 1960's. (For details and citations, see my posts under "Ozone and UV-B Science" on sci.env.) Fig. 1 in Rumen Bojkov's current paper on ozone trends (see latest issue of J. of Geophysical Research) shows an increase of 8% in Europe between 1964 and 1970. I do not doubt that ozone is now declining; indeed, I have measured a decline since 1990. However, I have questions about the statistical analysis of the various time series. Incidentally, while total ozone over my site (and the SE U.S.) during Nov. 1994 was the lowest ever measured over the U.S., total ozone was a record high for this site during NOv-Dec 1995. Forrest M. Mims III Sun Photometer Atmospherci network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.bio.ecology,sci.environment,alt.catastrophism Subject: Re: Safe places in ozone depletion?? Date: 19 Jan 1996 10:58:10 -0500 Greig Ebeling (eggsoft@sydney.DIALix.oz.au) cited Robert Parson's excellent ozone faq when he wrote (in part): >[from Parsons FAQ, Copyright 1995] >Several studies [Kerr and McElroy] [Mims] [Seckmayer et al.] [Zerefos >et al.] have presented evidence of short-term UV-B increases at middle >latitudes associated with the record low ozone levels in 1992-93. As >discussed in Part I, these low ozone levels are probably due to >stratospheric sulfate aerosols from the 1991 eruption of Mt.Pinatubo; Actually, the paper I wrote (Geophysical Research Letters, 1995) clearly explained how the low ozone I observed in 1993 was directly related to an unusual intrusion of very clear tropical air, which characteristically has a high tropopause and lower ozone. If there was a Pinatubo effect, it was a change in circulation that brought the tropical air up over Texas. Of course this might have also been caused buy the ongoing El Nino. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.bio.ecology,sci.environment,alt.catastrophism Subject: Re: Safe places in ozone depletion?? Date: 20 Jan 1996 00:28:08 -0500 Don Lowry (jlowry@tfb.com) wrote: >steve@unidata.ucar.edu (Steve Emmerson) wrote: >>According to the FAQ, between 66 degrees north latitude and 66 degrees >>south latitude, ozone has decreased by about 3% per decade for the >>period 1978-1991. It is left to the reader to decide whether or not >>this is "significant". >There's only one decade between 1978 and 1991!! OK, 1 1/3. How can >such a statistic be based on such a small sample? Why not say .3% per >year? Or does that not sound scary enough? And what it the margin of >error for this figure (surely not 0). Is it more or less than .3%? This post is precisely why I began the thread "Ozone and UV-B Science" on sci.env. I very much encourage those interested in ozone trends to refer to this thread. For example, while ozone has declined as noted above, ozone increased even more during the 1960's. See the thread for references. Incidentally, over the past few months TOVS (satellite) observations and my own observations in Texas have shown a dramatic increase in total ozone between the tropics and mid-latitudes. Of course this does not mean a "trend" toward higher ozone anymore than the record lows over my site and the SE U.S. in NOv 1994 indicated a "trend" toward lower values. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.bio.ecology,sci.environment,alt.catastrophism Subject: Re: Safe places in ozone depletion?? Date: 29 Jan 1996 16:55:09 -0500 Responding to Jim Scanlon, Timothy J. Thompson (Timothy.J.Thompson@jpl.nasa.gov) wrote (in part): .... >> One can plausible imagine occasionla intense peaks of light containing >> more energetic UV-B (but the same UVA) sweeping across the earth along >> with small weather systems. The intensity of the UVB would depend on the >> season, geography and altitude and be highly variable. >I don't know about this for sure, but I would tend to doubt it. I don't >think that solar UV is that variable. Actually, Jim Scanlon is correct. The clouds that accompany weather systems cause profound changes in global (meaning total sky) UV-B. Cumulus clouds (including alto cumulus with spacing between clouds) can cause increases of up to 27% in UV-B. (See my note on this in NATURE, 22 Sep 1994.) These increases can accompany cold fronts or warm fronts, especially when the sky between clouds is clear and not hazy. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Ozone and UV-B Science Date: 31 Jan 1996 18:07:37 -0500 Steve Emmerson (steve@unidata.ucar.edu) asked: >Now I'm curious. What is your best estimate of the global ozone trend? You'll have to give me a start point for the trend. Very generally, ozone is now in a post-Pinatubo recovery phase. According to TOVS observation (thanks to Arthur Neuendorffer at NOAA NESDIS), ozone at my latitude is definitely returning to pre-Pinatubo levels. This certainly confirms my observations using SuperTOPS. However, the Antarctic ozone minimum continues to show very low ozone and significant depletion has been noted in the arctic this winter. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: *A rainforest question -- please advice Date: 31 Jan 1996 18:14:52 -0500 Brandon: I spent 3 weeks in Brazil measuring ozone and UV for NASA. I learned that people burn trees simply to make a living for their families. Burning is now illegal without a permit--but they burn anyway. Otherwise they have no place to plant crops. It's a major problem. Last August-September, smoke often covered half the country. We burned most of our forests the same way long ago, and much has grown back. Tropical forests might not grow back as readily because of erosion and thin soil. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: New Ozone Web Site Date: 1 Feb 1996 20:20:31 -0500 Rob Simmon <simmon@daac.gsfc.nasa.gov> wrote (in part): >This data [from the TOMS instrument aboard Nimbus-7] along >with observations from Antarctica, first revealed the ozone hole. While it is true that Nimbus-7/TOMS provided outstanding maps of the annual Antarctic ozone minimum, the phenomenon was first observed by and reported on by a Japanese team using an antique Dobson spectrophotometer. When Farman's British team, also equipped with a Dobson, confirmed the Japanese findings, the NASA TOMS team took another look at their raw data and realized that they had erred in programming their system to ignore what they thought to be ozone values that were too low. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) Newsgroups: sci.environment From: jscanlon@linex.com (Jim Scanlon) Subject: Re: Safe places in ozone depletion?? Date: Sun, 4 Feb 1996 04:57:28 GMT > > <fmims@aol.com> wrote: > the clouds scatter UV radiation toward some areas while blocking it > from others. There is no net global (i.e. total-sky) increase in UV-B. > Since writing the publication cited above, I have confirmed its result > many times with actual measurements and simultaneous all-sky photos using > a fisheye lens. A new publication will follow. During typical summers at > my site since 1990, the modulation of UV-B by clouds is far more dramatic > than that by ozone. This would appear to confirm my (common sense) observation, that it would make sense to look for ozone induced UVR trends in areas that are the least cloudy. For example, the WMO has chosen Ushuaia as one of it climate monitoring stations. NSF also has one of it's six UVR stations there, which it operates in cooperation with the Argentinean Government. This is a pleasant city, but it is very cloudy. It would make more sense to locate instruments on the lee side of the Andes where it is less cloudy. The same goes for polluted areas. It is convenient for the operators to be located near cities (their natural habitat) but this is not the best place for getting trends in solar radiation. If gigantic telescopes on isolated mountain tops can be operated remotely, it would seem that simple UVR instruments can be made to do the same. It does not seem possible that astronomy is considered intrinsically more important than UVR. From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Safe places in ozone depletion?? Date: 5 Feb 1996 09:40:14 -0500 Jim Scanlon (jscanlon@linex.com) wrote about the placement of UV-B sensing instruments. I could not agree more with his suggestions. For those who do not know, Jim has actually made visits to the tip of South America, and he is quite familiar with the cloud cover there. He has also made ozone observations there. The data he collected will be analyzed by SPAN. Forrest M. Mims III Sun Photometer Atmopsheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Safe places in ozone depletion?? Date: 5 Feb 1996 09:40:20 -0500 Rich Puchalsky (richp@upx.net) wrote in response to Jim Scanlon, in part): [deletions...] >That, by the way, is one of the problems I see with Mim's project for >ground-based UV sensing (sorry, I forget the acronym off-hand). It doesn't >appear to have a connection with tenured faculty who will work on it and >steer graduate students into the project. That's critical for support of >a project like this, since graduate students go on to become the people >who largely influence the funding decisions. The Sun Photometer Atmospheric Network works very closely with the University of Oklahoma (which operates 4 sites in the Pacific through its SPaRCE program), Colorado Christian University (which sent a student to accompany to Brazil last summer) and Westmont College (where Stan Anderson, professor of chemistry, has derived very good equations for reducing total ozone from MicroTOPS observations). SPAN is discussing additional cooperation with other universities. As for funding, SPAN has received none beyond a Rolex Prize, two small unsolicited grants from Informedia and an unsolicited NASA contract (for work in Brazil). Yet SPAN observations have led to a number of original papers in the peer-reviewed literature. Six new papers are now in preparation. Clearly waiting for universities or the Federal government to establish a UV network has not worked. SPAN has shown it can be done on a shoe string budget. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: New Ozone Web Site Date: 5 Feb 1996 13:55:16 -0500 Barry M. Schlesinger (bschlesinger@nssdca.gsfc.nasa.gov) wrote: >In article <4erosv$44b@newsbf02.news.aol.com>, fmims@aol.com (FMims) >writes... > >>While it is true that Nimbus-7/TOMS provided outstanding maps of the >>annual Antarctic ozone minimum, the phenomenon was first observed by >>and reported on by a Japanese team using an antique Dobson >>spectrophotometer. >It is my understanding that a reexamination of the older Japanese data >shows that the measurements have very large errors, and that any very >low ozone values -- and some high ones also reported -- cannot be >considered reliable. If so, I have not seen anything in the peer-reviewed literature. I have , however, read discussions of the Japanese work in the literature, including the 1994 WMO ozone assessment. Do you have a citation? >>When Farman's British team, also equipped with a >>Dobson, [sic] confirmed the Japanese findings, >>the NASA TOMS team took >>another look at their raw data and realized that they had erred in >>programming their system to ignore what they thought to be ozone values >>that were too low. >I've told the details before. The Ozone Processing Team saw that the >low values were being thrown out by the software and was in the >process of investigating whether the values were correct or an >artifact of the algorithm or instrument calibration. The >Amundsen-Scott South Pole station was as that time reporting normal >ozone values, since corrected. (Why the sic? The Farman team did indeed use a Dobson.) As for the TOMS Antarctic data, the ozone minimum evolved over a period of years, and the fact remains it was first identified and confirmed by ground-based observations. TOMS later confirmed the extent of the minimum. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Safe places in ozone depletion?? Date: 6 Feb 1996 11:36:58 -0500 Rich Puchalsky (richp@upx.net ) wrote: >Jim Scanlon (jscanlon@linex.com) wrote: >: In article <4f54sk$d9n@newsbf02.news.aol.com>, fmims@aol.com (FMims) >wrote >: in response to Rich Puchalsky: >: [edit] >: SPAN[Sun Photometer Atmospheric Network] observations have led to a >: number of original >: > papers in the peer-reviewed literature. Six new papers are now in >: > preparation. >: Isn't this the "bottom line" in academic research? To be cited ? I am >Yes. >But the bottom line in _funding_ for academic research is to be part of >the academic organizational structure. Puchalsky is certainly correct. But I feel it's important to recognize that the dominance of academic and, especially, government science is a comparatively recent development. Consider, for example, that Federal expenditures for science and technology have increased 4000% since 1955 (constant dollars; source: 1995 budget historical tables). Reading the works of 19th century naturalists and that of today's amateur astronomers will demonstrate that solid science can be readily conducted by individuals or small teams with comparatively little funding. Even amateurs have demonstrated that homemade instruments can perform just as well as their professional counterparts which cost many times more. Consider that James Lovelock was first to discover the widespread presence of CFCs and other trace gases using an electron capture instrument of his own design and construction paid for with his own funds. While Puchalsky is correct about the current situation, I hope we will return to an era when individual workers who do not line up for Federal money are again taken as seriously as they once were. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Safe places in ozone depletion?? Date: 8 Feb 1996 13:27:45 -0500 Rich Puchalsky (richp@upx.net)wrote (in part): >I also think that individual, non-academic scientists >should be taken seriously, as long as they publish in >the peer-reviewed literature (as Mims does). >However, I am a bit puzzled by your (Mims) attitude >towards funding. You seem to be proud that SPAN >doesn't receive much government funding, and if I >remember a previous post on SPAN correctly you aren't >avidly seeking it for SPAN. Correct. >Yet you have often stated that the government should >fund a ground-based ozone-monitoring network, if I >remember the old threads about Happer et al correctly. My comments in this regard were about UV-B, not ozone. The government has spent billions of dollars on various ozone networks and ozone satellites (NOAA, EPA and NASA). I wrote only about the fact that in 1988 the government stopped funding its only UV-B network when that network showed a slight decline in UV-B rather than the expected increase. Governments spend far more on ozone research than on measuring UV-B that leaks through the ozone layer. As I have stated previously, if the government seriously believes that declining ozone poses a threat to the ecology and to human health, then it is incredibly irresponsible that the government has yet to seriously undertake the establishment of a dedicated, long-term national UV-B network. (I refer to the U.S. government. Canada, Austria, Australia and a few other companies have such UV networks.) The measurement of UV-B is at least as important as the measurement of basic weather parameters. >There seems to be some contradiction between your >scientific interest in having a functioning >ground-based UV monitioring network and your apparent >desire to keep SPAN as a showpiece of privately funded >science. Perhaps you could explain this a bit further. There is no contradiction in what you describe. SPAN is an ozone network, not a UV-B network. Except for my site, SPAN sites measure only direct Sun UV-B, not total-sky UV-B. If you are referring to my comments about the great imbalance in government funded UV-B and ozone research. Again, I find it quite astonishing that to this day the government which measures ozone so effectively has yet to make a commitment to the effective measurement of UV-B. The Dept. of Agriculture has made a good start with its climatic network. But this network is destined for a major disappointment if the DOA follows through with plans to eventually replace the present sensors (Yankee broadband instruments with a long life) with scanning filter radiometers (the filters will degrade and they are subject to near-IR and UV-A leakage). To preserve the time series, they should supplement the existing instruments, not replace them. A very positive aspect of the DOA network is that it is operated by a university, not the government. This is precisely the model I have advocated in prior posts. Academic researchers have a much-needed buffer between themselves and policy makers. >To confuse things even further, people seem to be >referring to you as an "ozone sceptic" in ways that I >haven't seen supported in your posts here. For >instance, a Rohm & Haas employee E-mailled me to say >that at least one respected scientist, Forrest Mims, >didn't beleive that current CFC policy (i.e. the CFC >ban) was warrented. Is this true, or was he >misrepresenting you? I know of your views as >expressed here on UV data but I don't know your >opinion of CFC policy as opposed to research policy. My work for SPAN has absolutely nothing to do with my personal views about government funding of ozone and UV-B measurements or CFC policy. (I began measuring UV- B in 1988 when I learned the government had stopped doing so. Several government and university scientists encouraged me in this effort, and my first publication on the subject was an article in SCIENTIFIC AMERICAN on how to make two kinds of direct-Sun UV-B radiometers. This article resulted in hundreds of leters from people who wanted to measure UV and ozone, which I why I stayed with the project.) But since you have asked, my personal view about the CFC ban is that it was a very wise move to eliminate the use of CFCs as propellants, foaming agents and pc board cleaning solvents. All these uses resulted in enormous amounts of CFCs being injected into the atmosphere. On the other hand, CFC's are perfectly safe when used in closed systems (air conditioners and refrigeration systems) that do not leak so long as the CFCs are properly collected when the system is either repaired or dumped. I assume these are the reasons the ban was made total. But it is important to note that while car air conditioners are notorious leakers, refrigerators are not. While in college back in 1965, I worked for a small but very sophisticated refrigeration and air conditioning repair company that efficiently recycled CFCs. Repairs were not conducted in the field. Instead, ALL CFC transfers were conducted inside a sealed room with a sump for the collection of any leaked material. To avoid additional repairs caused by oxidation problems (scale can block capillaries), all seals were soldered only while dry nitrogen was pumped through the tubes. Having observed first hand the very efficient recycling of CFCs and the repair of systems using CFCs by a company that developed its own methodology, I wonder why the use of CFCs in closed systems was banned entirely instead of being regulated. (Should you comment on this, please note the conditional nature of the previous statement.) And, as I have discussed in great detail (with citations from the peer-reviewed literature) on the sci.env thread "Ozone and UV-B Science," I also wonder about some of the questionable statistical methods which have been used to describe the ongoing decline (which I have measured) in total ozone. (It appears from TOVS data that mid-latitude ozone levels in the NH are returning to pre-Pinatubo levels this winter. My measurements here certainly confirm this. SH values and those in the Arctic and Antarctic remain low.) Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: labow@wrabbit.gsfc.nasa.gov (Gordon Labow) Newsgroups: sci.environment Subject: re:Why are they lying to us about CFCs? Date: 9 Feb 1996 18:08:25 GMT bachert@ix.netcom.com(Richard Bachert) writes: >..... how these CFCs -- which are many times heavier than air -- > make their way across the equatorial zones to gather high above >the South Pole for the sole purpose of punching a hole in the >ozone layer and upsetting Algore et al? If any of you can help with >this, please contact me. I'll answer this question with another question: Why isn't all the salt at the bottom of the ocean?? NaCl is much heavier than water, right? (28 to 10) By your reasoning the salt CAN'T POSSIBLY be near the surface, can it? If you can't figure out the answer to this question, I would recommend taking a high school chemisty or physics course. G.L. P.S. There is also SAND from the Sahara that gets blown into the Stratosphere and carried to places like Texas & Florida. How could this happen? Sand is WAY heavier than air...... From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Safe places in ozone depletion?? Date: 10 Feb 1996 12:44:04 -0500 Rich Puchalsky (richp@upx.net) wrote (in part): >FMims (fmims@aol.com) wrote: >: There is no contradiction in what you describe. SPAN is >: an ozone network, not a UV-B network. Except for my >: site, SPAN sites measure only direct Sun UV-B, not >: total-sky UV-B. If you are referring to my comments >I have to admit that I've gotten hazy on the differences between the >instruments used to measure total-sky and direct UV-B. Let me re-read the >FAQ and some old posts and get back to you once I can ask >a more intelligent followup question. I don't recall seeing the following definitions in Robert Parson's faq, so here they are: Direct Sun UV-B: That UV-B received directly from the Sun (as in looking at the Sun through a collimator tube having a field of view equal to the diameter of the Sun or about 0.5 degree). Diffuse UV-B: The UV-B scattered from the air molecules in the sky and anything floating in it (clouds, smoke, dust, pollen, spider webs, volcanic aerosols, sulphates, etc.). Total-Sky (or Global) UV-B: The sum of direct and diffuse UV-B as received by a detector with a cosine response that looks straight up at the zenith sky. (Global is the traditional term, but an anonymous reviewer of one of my papers criticized its use since satellite observations have given a more literal meaning to the term.) A thin layer of Teflon provides a good diffuser to measure total-sky UV-B with a cosine response. Shadow the diffuser with a blackened disk on a thin rod and you measure only the diffuse UV-B. Subtract the latter from the former and you find the direct Sun UV-B. I also measure direct Sun UV-B with instruments designed solely for that purpose (MicroTOPS and radiometers described in SCIENTIFIC AMERICAN and SCIENCE PROBE). If there is sufficient interest and if I can find the time, I may develop a faq to be called "Ozone and UV-B Science." This faq will not duplicate Parson's. It will, however, stress real-world problems in measuring ozone and UV-B and will also discuss the importance of proper statistical methods in ascertaining trends in tinme series of both kinds of data. Incidentally, I very appreciate the tone of Puchalsky's response. If more participants on sci.env would return to this approach, the forum would again be taken more seriously. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: re:Why are they lying to us about CFCs? Date: 10 Feb 1996 12:58:20 -0500 Gordon Labow (labow@wrabbit.gsfc.nasa.gov) responded with appropriate examples to Richard Bachert's (bachert@ix.netcom.com) comments about CFCs being heavier than air. When I worked for a refrigeration company back in college, it was interesting to watch leaked CFC flow down the sloped floor of the specially enclosed room where all CFC exchanges were made. The CFCs flowed into a sump, where they were recovered. The reason the room was carefully sealed, of course, is that any breeze from air conditioners and opening doors would quickly dissipate the material and disperse it throughout the building. There are several very valid questions about the current ozone paradigm, including, for example, the selective nature of data used in ground-based trend studies. Perpetuating the myth that CFCs cannot be distributed throughout the atmosphere because they are heavier than air serves no purpose other than to muddle the question. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Lost in the Ozone Again (was: Economic Freedom...) Date: 15 Feb 1996 09:26:47 -0500 >Sam McClintock <sammcc@nando.net> wrote: >FMims wrote: >> Those who work in any field of science quite >> properly lose credibility with the general >> public when they limit their criticism to >> books that do not support a particular >> paradigm. >This goes a lot deeper that just supporting a >particular paradigm. First, scientists are not >obligated to criticise or support any book that is not >scientifically rigorous. A scientist is judged first >and foremost by his work, not his external >criticisms. Are you saying that those atmospheric >scientists that fail to criticize Gore's book are not >producing credible research? Which would lead us to >the question, since most scientists have yet to yield >any written criticism of any book, that the CFC/ozone >research is not credible? Gore's book was a best seller and received considerably more attention than Ray's book. The ozone and UV-B sections of both books are flawed. Yet I have only seen Ray's book attacked in this forum. Could there be a connection with the dismissal of William Happer by Gore for his statements regarding the lack of measurements of UV-B? [deleted redundancies...] >Are you supporting this book to make a similar claim, >e.g. that CFCs do not pose a threat to the ozone >layer? But I don't support Ray's book. As noted in my post to which you have responded, I have criticized Ray in a published magazine article and in this forum. Consider another book that gives the erroneous impression that Ushuaia is always under the ozone hole and which claims that, "In Patagonia, hunters now report finding blind rabbits; fishermen catch blind salmon." (From "Earth in the Balance" by Al Gore. See the chapter titled "Buddha's Breath," p. 85.) Do you support this book? These statements represent my personal views and are offered in an ongoing effort to return objectivity to the ozone and UV-B debate. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Lost in the Ozone Again (was: Economic Freedom...) Date: 15 Feb 1996 15:00:38 -0500 d.soft@freenet.hamilton.on.ca wrote in response to my post: >In article <4fvfr7$qs5@newsbf02.news.aol.com> you wrote: >: Gore's book was a best seller and received >:considerably more attention than Ray's book. The >:ozone and UV-B sections of both books are flawed. Yet >:I have only seen Ray's book attacked in this forum. > The reason for this observation is crystal clear. ><Never> have I seen anyone here defend a position >through references to Gore's book. Yet <REGULARLY> we >see ditto-heads referring to Decomposing Dixy's book >in their rabid denouncements of any and all science >that produces results that are outside their political >model of how the world must work. Agreed. Yet Gore's book was widely praised and cited in the popular press, which, may I say, has considerably greater circulation than this forum. Ray's book was widely ignored in the popular press. > What is to be said of the quality of science in a >publication that states that CFC's can not reach the >stratosphere because they are heavier than air? > Such a statement is not only patently false, but it >is ignorant of basic science. If such a statement is >made and not retracted for years after the statement >is made, either the person making the statment is >being dishonest, or must be profoundly ignorant of >science to reject the criticism. I have already written that I criticized Ray for this serious error in a published magazine article, as I have done in this forum. Do you apply the same criteria to "Earth in the Balance", a book that gives the erroneous impression that Ushuaia is always under the ozone hole and which claims that, "In Patagonia, hunters now report finding blind rabbits; fishermen catch blind salmon." (Quotation from a chapter titled "Buddha's Breath," p. 85.) As noted elsewhere, this book was a best-seller; Ray's book was not. > If we assume that Decomposing Dixy's comments were >not a result of dishonesty - we are forced to conclude >that they were made out of ignorance. And if here >comments were made out if ignorance of such basic >science, we should conclude that she, like Gore, was >not writing as a scientist - she simply was not >qualified at that point to do so. While taking credit for any errors in his book, Gore acknowledged by name several prominent, well known scientists who reviewed his chapters on ozone and UV-B. These comments are my own. They are offered in an ongoing effort to return objectivity to the ozone-UV-B controversy. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN Newsgroups: sci.environment From: roosen@netcom.com (Robert Roosen) Subject: Re: Discovery of the ozone hole Date: Sat, 17 Feb 1996 22:15:22 GMT Jim Scanlon (jscanlon@linex.com) wrote: : This would then appear to be a case of withholding preliminary data to : forestall being pre empted. i.e.,. having your ideas stolen. : For example, if NASA, or others, had known of the suspicious decline, they : could have gone over their data and "discovered" the Ozone Hole, just as : they did later. (They often get credit for the discovery anyway!) Data analysis is one of the least appreciated and funded parts of the scientific process. Most observers are quite overwhelmed after a few years of collecting data. Changes and glitches are continually introducing themselves. Getting long term records on a single, accurate scale is a massive undertaking. It is not unusual for a researcher to take years to analyze data to the point where a new result is announced. A few reasons that come to mind are: 1) Science is based on re-search. 2) Observers hate to have to retract published data. 3) It takes a while to realize that the observations are correct. 4) There are always further refinements possible, and most people tend to analyze until the results are acceptable in public, then stop :-) According to Stigler's Law of Eponomy, it is usually the second person to announce a discovery that gets the public credit. imo, this is partly because the "pure scientist" does not push for credit, and usually only a few specialists accept and understand the announced result at first. Then someone more politically aware actually gets the result publicly accepted. Of course, there are also fads in science. Right now the fad seems to be to believe theories that are way beyond what the observations can support and that ignore observations that the theoreticians cannot handle. Many years ago it was known that total ozone above any given site can be extremely variable. Changes of thirty per cent in a few hours are not unusual. Changes of one hundred per cent in a day have been reported more than once. In the face of this knowledge, few observers accept the ozone trend analyses that keep on being published. The data sets are far too limited to support those speculations. Still, the public view is of "the ozone layer" as some amorphous, homogeneous place. I prefer to call it "the ozone region", where clouds of ozone blow around, forming eddies and pools. At some point, the variability of ozone will be recognized. I wonder who will get credit for that "discovery" :-) Newsgroups: sci.environment From: roosen@netcom.com (Robert Roosen) Subject: Pinatubo and Ozone--a Question Date: Sun, 18 Feb 1996 07:35:29 GMT Ozone amounts measured in the UV are commonly reported in Dobson units, rather than the metric units used for measurements in the visible spectrum ozone band. One reason that an esoteric unit like the Dobson unit is used is that the absorption of UV light by ozone is strongly affected by the temperature of the ozone that is doing the absorbing. Atmosospheric temperatures vary as a function of altitude, season and other factors. Hence I guess that analyzing UV observations includes some sort of model assumptions about the distribution of temperature and ozone. When sulfur dioxide is injected into the stratosphere by volcanic activity, it soon forms a sulfuric acid coating on available condensation nuclei. This coating is quite black in the thermal IR, and hence the stratosphere is cooled by the increased thermal emission. This produces a reduction in measured amounts of ozone reported in Dobson units due to the decreased absorption of UV that results from the temperature decrease. My question is this: How much of the apparent decrease in ozone amounts reported by some UV observers is actually due to the change in stratospheric temperatures that resulted from the Pinatubo eruption? From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Discovery of the ozone hole Date: 19 Feb 1996 01:38:17 -0500 Robert Roosen (roosen@netcom.com) wrote in response to >Jim Scanlon (jscanlon@linex.com) wrote: >: This would then appear to be a case of withholding >:preliminary data to forestall being pre empted. >:i.e.,. having your ideas stolen. [snip] Roosen responded: > Data analysis is one of the least appreciated and >funded parts of the scientific process. Most >observers are quite overwhelmed after a few years of >collecting data. Changes and glitches are continually >introducing themselves. Getting long term records on >a single, accurate scale is a massive undertaking. This is an amazing development. A scientist known for analyzing (and publishing) ozone, optical depth and water vapor time series of 30 years or more has joined this forum. His point about the difficulty of getting funding for studying long-term records is well illustrated by the failure of NOAA to support a careful reprocessing of the Berger network data which would include important corrections identified by John DeLuisi and others. (Jim Scanlon has discussed this need in this forum.) > It is not unusual for a researcher to take years >to analyze data to the point where a new result is >announced. A few reasons that come to >mind are: >1) Science is based on re-search. >2) Observers hate to have to retract published data. >3) It takes a while to realize that the observations >are correct. >4) There are always further refinements possible, and >most people tend to analyze until the results are >acceptable in public, then stop :-) [snip] > Of course, there are also fads in science. Right >now the fad seems to be to believe theories that are >way beyond what the observations can support and that >ignore observations that the theoreticians cannot >handle. Many years ago it was known that total ozone >above any given site can be extremely variable. >Changes of thirty per cent in a few hours are not >unusual. Changes of one hundred per cent in a day >have been reported more than once. In the face of >this knowledge, few observers accept the ozone trend >analyses that keep on being published. >The data sets are far too limited to support those >speculations. Actually, many people do indeed accept the published ozone trend studies, in spite of the questionable statistical methods employed in some. For example, the often cited 1994 WMO ozone assessment includes ground- based trend studies that fail to include substantial data collected during the 1960s. Since significant increases in ozone were measured (and published) during the 1960's, the failure to include all the data is a serious omission. Problems in other published studies include the mixing of satellite with ground-based data, the use of preliminary Meteor-3/TOMS (satellite) data which NASA has specifically warned are not suitable for publication, the selective use of Dobson data (data from various stations are not used for various reasons, which, to my knowledge, have never been fully explained) and, possibly, the use of substantial data from instruments subject to significant air mass and aerosol dependent errors (M-124). I also wonder about artefacts caused by the diurnal cycle of tropospheric ozone. Last summer at my site, a Brewer and a SuperTOPS measured diurnal changes of up to 15 Dobson units or some 5% of the total ozone caused by tropospheric ozone. Finally, to my knowledge, no recent trend studies have considered the lengthy time series from the Astrophysical Observatory of the Smithsonian Institution (which cover ca. 1924 to about 1964 or so). (Roosen and others have published papers on this work.) > Still, the public view is of "the ozone layer" as >some amorphous, homogeneous place. I prefer to call >it "the ozone region", where clouds of ozone blow >around, forming eddies and pools. > At some point, the variability of ozone will be >recognized. I wonder who will get credit for that >"discovery" :-) These points, which are obvious to Roosen and anyone else who has actually measured ozone in the field, are just not widely understood. As Roosen notes above, very major changes can occur over a day or so. Several years ago my son Eric and I studied ozone fluctuations across the width of a TOMS resolution element about the time Nimbus-7/TOMS was overhead. While driving east-west along various interstate highways in Texas, New Mexico and Arizona, we found fluctuations of up to a few percent within a single TOMS resolution element (to be published when I can find the time). In the grand scheme of things, these ripples are smoothed by the satellite's mapping capability. But they show that there are very interesting short-term changes in total ozone. Make 100 ozone observations during any 10-minute period, and you'll almost always see changes. Careful statistical methods can accomodate some, perhaps most, such fluctuations. These comments are offered in an effort to add objectivity to the ongoing ozone-UV-B controversy. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Safe places in ozone depletion?? Date: 19 Feb 1996 01:38:18 -0500 Robert Roosen (roosen@netcom.com) wrote to either this or a relarted thread (sorry, I lost the citation): > Ozone amounts measured in the UV are commonly >reported in Dobson units, rather than the metric units >used for measurements in the visible spectrum ozone >band. > One reason that an esoteric unit like the >Dobson unit is used is that the absorption of UV light >by ozone is strongly affected by the temperature of >the ozone that is doing the absorbing. Atmosospheric >temperatures vary as a function of altitude, season >and other factors. Hence I guess that analyzing UV >observations includes some sort of model assumptions >about the distribution of temperature and ozone. Roosen makes an important point, for most ozone measurements are not corrected for the impact of stratospheric temperature changes on the Bass-Paur (or the older Vigroux) ozone absorption coefficients. Both ground and satellite inferences of total ozone from ratiometric measurements (a.k.a. dual differential absorption spectroscopy) in the UV-B can be affected by temperature-induced shifts in the absorption coefficients. > When sulfur dioxide is injected into the >stratosphere by volcanic activity, it soon forms a >sulfuric acid coating on available condensation >nuclei. This coating is quite black in the thermal >IR, and hence the stratosphere is cooled by the >increased thermal emission. > This produces a reduction in measured amounts of >ozone reported in Dobson units due to the decreased >absorption of UV that results from the temperature >decrease. Another factor is that the SO2 aerosols scatter UV-B more efficiently at some wavelengths than others. This has caused well known errors of up to a few percent in some satellite and ground-based measurements. Dobson and Brewer spectrophotometers cancel much or all of aerosol-induced error by measuring at two pairs of wavelengths. Aerosol errors can also be minimized by observing a single pair of closely-spaced wavelengths (which is why I have concentrated on designing instruments that measure total ozone at, e.g., 300 and 305 nm or 303 and 310 nm rather than using the traditional 20 nm spacing). Incidentally, readers of Roosen's post should know that he has specialized at measuring total ozone in the visible Chappuis band, which has two peaks in the orange near 600 nm and which extends from the green to the red wavelengths. Roosen has also specialized in evaluating Chappuis band (and other) observations by the Astrophysical Observatory of the Smithsonian Institution at various sites going back to the 1920's and even before. (For example, as noted in a publication by Paul Gotz in 1954 and by others, Chappuis band observations by the AOSI show significant ozone loss following the eruption of Katmai in 1912.) Although ozone absorption at Chappuis wavelengths is much less (typically <10%) than in the UV-B, the Chappuis band is unaffected by temperature variations within the ozone layer. My question is this: > How much of the apparent decrease in ozone >amounts reported by some UV observers is actually due >to the change in stratospheric temperatures that >resulted from the Pinatubo eruption? I measured distinct drops in ozone associated with sharp increases in aerosols during the first few years after Pinatubo. Balloon observations around the world also gave similar results. But Roosen's question requires that we now use ozone absorption coefficients that reflect the temperature drop within an aerosol layer. This is complicated, since the aerosols were never uniformly distributed within the entire ozone layer. But it does warrant more study. If anyone is aware of any publications or studies that show ground- or satellite-based ozone measurements corrected for temperature-induced absorption coefficient changes, I would very much appreciate receiving e-mail with the details. These comments are offered in an effort to add objectivity to the ongoing ozone-UV-B controversy. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: CFCs Dominate Ozone Depletion Beyond Reasonable Doubt Date: 19 Feb 1996 01:38:55 -0500 Len Evens (len@schur.math.nwu.edu) wrote in response to Jim Scanlon's post on the recent paper in NATURE on CFCs and ozone loss: [summary of paper deleted...] >By the way. Since we know as well as we know >anything else in science that the ozone layer filters >out UV radiation (in fact that is what creates it), >suppose we found that on a world wide basis the ground >level UV B stayed more or less constant over a long >period of time. Wouldn't you conclude there must be >something else funny happpening on a large scale in >the atmosphere? Any ideas for such a phenomenon? Contributing factors would be increasing anthropogenic and natural haze combined with significant increases in tropospheric ozone (which, on a molecule per molecule basis, absorbs UV-B more efficiently than stratospheric ozone because of multiple scattering from aerosols in the troposphere). Measured increases in global cloud cover may also plan a significant role. Billions of dollars have been spent measuring and studying ozone, but these fundamental issues regarding UV-B have simply not been adequately stuidied. >Also, if we are to establish this worldwide network to >measure UV B, we had better be quick about it. Since >CFCs have been banned, it is estimated I believe that >ozone levels will decrease for another ten years or so >and then start to rebound. Since ozone and UV >B vary locally for a large number of other reasons, >sorting this all out may take longer than the CFCs >will play a significant role. As Jim Scanlon and I have pointed out, serious scientists have been calling for a global UV-B network since at least 1974, four years before the launch of Nimbus-7/TOMS and long before the current ozone decline was known or predicted. >This will surely be interesting science, but somehow I >suspect that at least some of the motivation behind >the push for a UV measurement network is a hope that >it will be proved that CFCs are innocuous and there is >no ground level effect. The scientifically curious >among us will still want to know the answers, but >there are proably a few pwople who will lose interest. Perhaps I missed it, but this is the first time I've read or even thought of this prospect. I have, however, heard professional scientists suggest that government UV-B measurements in the U.S. were stopped and not resumed (until recently) because of concerns that the measured values did not reflect predicted values. (This matter was discussed some time ago in sci.env. with regard to the dismissal of William Happer of the Dept. of Energy after he made public statements about the need to measure UV-B.) Ozone changes notwithstanding, the most important reason to establish a global network of uniform (or standardized) UV-B instruments is that excessive exposure to UV-B can cause cancer while other things we measure do not. It's simply not an issue of curiosity- driven science. Measuring UV-B should be as routine as measuring barometric pressure, temperature, wind speed and even ozone. These comments are my own and are offered in an effort to lend objectiviy to the ongoing ozone-UV-B controversy. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) Newsgroups: sci.environment From: roosen@netcom.com (Robert Roosen) Subject: Re: Discovery of the ozone hole Date: Mon, 19 Feb 1996 20:47:41 GMT Forrest Mims wrote: >Several years >ago my son Eric and I studied ozone fluctuations across >the width of a TOMS resolution element about the time >Nimbus-7/TOMS was overhead. While driving east-west >along various interstate highways in Texas, New Mexico >and Arizona, we found fluctuations of up to a few >percent within a single TOMS resolution element (to be >published when I can find the time). In the grand >scheme of things, these ripples are smoothed by the >satellite's mapping capability. But they show that >there are very interesting short-term changes in total >ozone. Make 100 ozone observations during any 10-minute >period, and you'll almost always see changes. Careful >statistical methods can accomodate some, perhaps most, >such fluctuations. We are coming to recognize that there is a considerable amount of fine structure in the ozone region. The amount of variability reported depends in part on the field of view of the instrument used to make the measurements. The Chappuis band observations that I work with are based on the measurement of normal incident solar radiation. The angular diameter of the sun is about half a degree, or 1/100th of a radian. Thus I am working with the cone of atmosphere illuminated by the solar disc. To give some idea of the size of this cone, here are a few example calculations: If the sun is at the zenith (air mass = 1.0), then the diameter of the cone at twenty five kilometers altitude is 25km X .01 = 250 meters. At air mass ten (close to the horizon), the diameter is 250km X .01 = 2.5 km. Near the horizon, we are looking at more of the sky and averaging over a longer path length. We observe what is expected. Namely, the detected variability is greatest near the zenith and least near the horizon. This is true for all the parameters measured--ozone, aerosols and water vapor. When we first published a comparison of the Dobson and Smithsonian results from Table Mountain Obs. in the 1920s, we found that the Smithsonian Chappuis band results were more variable than the Dobson values for the same days. This caused us to question the accuracy of the Smithsonian data. We did not realize at the time that there is always a large scattered light component in Dobson measurements and the effective "head print" of a Dobson instrument is much larger than that of our instruments. A rough guess puts the area of sky covered by a Dobson at 25 to 50 km in diameter at an altitude of 25 km. The "head print" of an ozonesonde is effectively a line running from the earth to the stratosphere. Looking at some of the work of DeLuisi and Sticksel done in the 1960s, it seems that ozonesondes measure even more variability than the Chappuis band work. In other words, the vertical variations may be even more pronounced than the horizontal ones derived from ground based work. It will not surprise me if it turns out that ozone sometimes has fine structure on the order of ten per cent or more over a horizontal range of less than a kilometer. We need more and better observations in order to find out. My plan is to set up an array of about 100 Chappuis band instruments here in San Diego County, spaced about 20 km apart. Such an array will make it possible to detect clouds and gaps in the ozone region on a real time basis. This will be useful for ozone climatology studies as well as providing predictions in real time of the UV hazard. I heartily endorse Jim Scanlon's comments on the Berger/Briggs UV studies. Having the person who made the observations available to update the data set and correct the older work is a great stroke of luck. There have been many times that I wished I had F. E. Fowle or Dr. Abbot available to help me reduce their data :-) I hope that Berger is able to get started on that analysis as soon as possible. Robert From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Lost in the Ozone Again (was: Economic Freedom...) Date: 19 Feb 1996 16:28:41 -0500 Scott Nudds (af329@freenet.hamilton.on.ca) responded to some of my comments about errors in the books by Dixy Ray lee and Al Gore. Clearly Gore's book received more publicity because of his office. As for his scientific background, the book clearly acknowledges by name various scientists who reviewed his material on ozone and UV-B, including Sherwood Rowland. I do not know if Rowland was aware that the book includes the following: [snip] [Mims wrote:] >: and which claims that, "In Patagonia, >: hunters now report finding blind rabbits; fishermen >: catch blind salmon." > I have not read Gore's book, so I can't defend such comments. But this >statement may very well be accurate. What hunters <report> and what is >real, may however, be two different things. I remember reports of blind >sheep, don't you? As I keep sheep, I am particularly interested in this subject. The blind sheep reports have been widely published and broadcast. I was sent a TV video broadcast a few years ago (by the producer) which is used in schools that states that sheep have been blinded by high UV-B. However, these reports have been checked by various workers, and published papers and articles blame the problem on various eye diseses unrelated to high levels of UV-B. However, some eye diseases may be related to higher than normal UV-B, so I don't completely rule anything out at this point. Perhaps Jim Scanlon, who has twice visited the region from where such reports came, can comment on this again. Incidentally, Gore's book with the blind rabbits and salmon anecdote was reprinted with the anecdote intact, even though the stories were never substantiated. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Discovery of the ozone hole Date: 19 Feb 1996 22:56:50 -0500 Robert Roosen discussed the angular field of view of ozone monitoring instruments and related topics. I was especially interested in his comments re. Jim Scanlon's suggestions on the Berger time series. It is obvious that we have both made very similar observations of fine structure in the ozone "layer," he in the Chappuis band and me in the UV-B. I have two questions: 1. Do you know the angular field of view (fov) of the old Smithsonian instruments? 2. Do you see any merit to designing an instrumnt with a fov smaller than the angle subtended by the solar disk, say 0.25 degrees or even less? (I understand that such an instrument would be difficult to point and might require optics rather than a simple collimator.) Thanks very much for your input on this. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Lost in the Ozone Again (was: Economic Freedom...) Date: 20 Feb 1996 11:10:07 -0500 Scott Nudds wrote: [snip] [F. Mims wrote:] : Incidentally, Gore's book with the blind rabbits and salmon anecdote was : reprinted with the anecdote intact, even though the stories were never : substantiated. Why not call the publisher and find out why? Besides keeping sheep for fun, I write books for a living. Publishing contracts always leave the correction and updating of new printings to the author. Perhaps Gore was simply not aware that these reports have been checked and found wanting. I would suggest that Gore be asked, but when I sent him two faxes in 1993 re. the very high UV-B levels that summer, he never responded. One of his staffers told me by phone that he (Gore) would have "no" interest in measurements of high UV-B. Similar faxes to Robert Watson (a White House science advisor) were also unanswered. If I ever find time to do a UV-B faq, perhaps I can include these faxes and my notes in a separate file. (Lest the impression be left that I am cynical of the government's interest in UV-B, I should add that the EPA responded very rapidly and professionally to my inputs, sent me to Japan to give a paper, and asked me to visit Washington to give a second paper. They also arranged an interview with Congressional staffers, who were quite knowldegeable and who asked the right questions.) Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Ozone Questions: was Re: Ozone and UV-B Science Date: 21 Feb 1996 10:02:51 -0500 Andrew Russell (arussell@BIX.com) wrote (in part): >Why did the global ozone layer *rise* >so dramatically during the 60's? Why did it *rise* >from 1985 to 1991? The increase during the 1960's is discussed in detail in various papers I cited previously. The 1994 WMO ozone assessment begins trends at 1964, thus missing much of the increase, even though abundant data are available. There Antarctic trends begin in 1957. Various climatological factors modulate the amount of ozone. Circulation changes can cause total ozone to increase or decrease. For example, at my Texas site persistent tropical flow from the Gulf of Mexico almost always means low ozone. While being persistently under the arctic jet may mean high ozone. Various reactions with volcanic aerosols (SO2), chlorine, fluorine, iodine and water vapor in the stratosphere (which may come from the dissolution of methane) can cause ozone to decline. Globally, ozone declined and did not increase from 1985 to 1991. > 3) Decreased ozone will result in increased UV-B. >False (partly). It's usually not measurable from >slight decreases in the stratospheric ozone layer. In >the case of very large scale decreases in >the ozone layer, yes. But such decreases are >significantly beyond the scientific claims of damage >from CFCs (on a global basis, Antarctica is of >course a special case). Forrest Mims' SPAN data has >shown that factors (esp. meteorological) other than >the ozone layer can have a very large effect on UV-B >levels. Since the Scotto study in the 1980's, there >has been *no* government funded research in UV-B >levels. In fact, such measurements are *opposed* by >politicians (notably Albert Gore) who claim >that ozone depletion requires desperate measures. Changes in ozone almost always are accompanied by easily measured inverse changes in UV-B. Some ozone changes are huge (rarely up to 100% in a single afternoon when a system moves in). What I have found so interesting is that factors other than ozone generally have a much greater effect on UV-B than typical changes in ozone. Just a few days ago I observed two sustained (ca. 1 hour) 20-25% increases in UV-B caused by scattering from slow moving cumulus clouds. In my experience, such increases resulting from low ozone are much less common than those caused by clouds. I have observed this phenomenon many times in New Mexico, Texas, Colorado and Hawaii. On the other hand, anthropogenic haze and smoke containing black carbon can cause very significant reductions in UV-B even when the total ozone amount is lower than normal. I have observed this many times in Texas, Maryland, Washington, DC and Brazil. Biomass burning in Brazil can cause a measured reduction in UV-B of 80% (as it did at Cuiaba on 31 Aug 95, a day when thick smoke covered much of the country and even closed airports). The famous volcanic fog or vog of Hawaii is very unusual in that it causes a slight increase in UV-B as opposed to the UV-B in a clear area without vog. I have observed this using various instruments (including automated data loggers) and will report my findings when time permits. Typically, the UV-B at Kona will be higher than at Hapuna Beach some 30-40 km north when the former is under a layer of vog and the latter is clear. I don't believe the increase is an anomalous effect of my instrument's slightly imperfect cosine response since water vapor haze causes a decrease in UV-B. One published study based on model results has shown that stratospheric volcanic aerosols can cause an increase in UV-B. But Hawaiian vog is low altitude stuff. Perhaps the high acidic content of vog somehow reduces tropospheric ozone. (But total ozone at both sites is usually about the same.) Or perhaps the very small size of the aerosols plays a role. > 4) Increased UV-B will result in increased >incidences of skin cancer. Not my field. [snip...] Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Lost in the Ozone Again (was: Economic Freedom...) Date: 24 Feb 1996 00:33:29 -0500 Jim Scanlon (jscanlon@linex.com) related a fascinating account of his visits to the southern tip of South America in his personal effort to track down the tales about blind rabbits and sheep. I very much enjoyed reading this. While Scanlon's impressions of the heat of the Sun on his face are anecdotal, I experienced a similar phenomenon during episodes of very high UV-B that occurred in Texas for a few days in 1993. Experiences like these will forever remain anecdotal--although mine was corroborated by actual measurements. Scanlon's reports about increased rates of sunburn are also anecdotal. I heard similar reports here in South Texas during the high UV-B episodes during the summer of 1993. For example, an Hispanic woman at my church in her 30's received her first ever sunburn, a painter was sunburned although he stayed in the shade all day, etc. The major grocery store chain in South Texas (HEB Co.) was kind enough to provide sales figures for its various sunburn ointments, and there was a statistically significant increase in the sales of certain products over the previous 2 years. I presented these findings along with considerably more robust data on UV and ozone in an invited paper at a conference sponsored by the EPA in Washington. (The ozone and UV-B data were published in Geophysical Research Letters.) Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment,talk.environment Subject: Re: CFCs (was re: what about 25000 nuclear reactors) Date: 24 Feb 1996 10:58:17 -0500 Bernd Kuemmel <BEK@MMF.ruc.dk> wrote in response to a post by Greig Ebeling: [much deleted...] >> This figure has never been confirmed, and shows a complete >> lack of understanding of the high variability of ozone daily, >> seasonally and globally, and as a result of natural phenomenon >> such as volcanic activity. >The only problem with volcanic chlorine is, that it is in the >form of HCl. As eruptions also are accompanied by water >emissions most of the volcanic chlorine does not stay in the >stratosphere! The significant ozone decline that followed the major eruption of Katmai (Alaska) in 1912 deserves much more study. Instead, it is never cited in current papers. Measurements in the Chappuis ozone absorption band by the Astrophysical Observatory of the Smithsonian Institution at Mount Wilson, California, in 1912 were studied by Gotz and others, who reported on the ozone decline in various publications. Katmai erupted when inorganic chlorine from anthropogenic sources was probably at negligible levels (excepting haloids such as methyl bromide and methyl bromide from the intentional burning of grass and woodlands). Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Ozone Hole = Blind Sheep? Date: 24 Feb 1996 19:21:34 -0500 There has been much speculation about whether increased solar UV-B that accompanies passage of the ozone hole over the tip of South America has caused blindness in sheep, rabbits and salmon. (See, for example, "Earth in the Balance" by Al Gore.) Various visits to the region (including by Jim Scanlon, a contributor to sci.env) have failed to verify such claims. A newly published paper reports on surface UV-B measured at Ushuaia, Tierra del Fuego, Argentina, by an SUV-100 scanning spectroradiometer during all of 1992. Susana Diaz, John Frederick, Tom Lucas, Rocky Booth and Irina Smolskaia report in "Solar ultraviolet irradiance at Tierra del Fuego: Comparison of measurements and calculations over a full annual cycle" (GEOPHYSICAL RESEARCH LETTERS, 23, 355-358, 15 Feb 1996) that passage of the ozone hole over Ushuaia during the spring of 1992 caused two sharp spikes in UV-B at 305 nm. An examination of their Fig. 1 (p. 356) shows that these two spikes are both higher than the mean summer levels of UV-B but below two summer peaks. (Total ozone during the spring spikes was much lower than those that occurred in summer, but the higher sun angle in spring reduces the UV.) In view of the brief duration of the spring spikes and the fact they do not exceed the summer spikes, it would seem unlikely that the enhanced UV-B would be sufficient to cause blindness in sheep, rabbits and salmon. However, possible effects on organisms that inhabit areas shaded by shrubs and trees cannot be ruled out if such vegetation had not fully leafed out at the time of the spikes. Such effects, which have been little studied, can be counter-intuitive and highly complex (e.g. UV-B may kill or stunt predatory microorganisms, thus allowing their prey to flourish). Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.energy,sci.environment,talk.environment Subject: Re: funding science Date: 24 Feb 1996 23:59:44 -0500 Len Evens wrote (in part): >Might I humbly suggest that Forrest Mims might also make >mistakes. Indeed, it is even possible that he in entirely >in the dark about some issue, including ones he comments on. I have posted numerous comments in sci.env regarding the ozone layer, UV-B and the atmosphere's optical depth. If Len Evens or any others have noted any errors in these posts (which can be retrieved from various net archives), I will immediately correct them. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment,talk.politics.libertarian Subject: Re: Why are they lying to us about CFCs?? Date: 26 Feb 1996 02:37:47 -0500 Len Evens (len@schur.math.nwu.edu) wrote about CFCs, misinformation and related topics. He then wrote about volcanoes: [snip...] >Forrest Mims refers regularly to an >eruption in about 1912 after which supposedly there was >an effect on ozone levels. So maybe that happened >then. However, the recorded ozone depletion since the >introduction of CFCs cannot be reasonably attributed to >Chlorine from volcanos, at least if Robert Parson, the >WMO, and almost the entire community of atmospheric >chemists are to be believed. While we are at it, >throw in the committee which awarded the Nobel prize in >chemistry this year. What Evens describes as a supposed effect was measured by the Astrophysical Observatory of the Smithsonian Institution at Mount Wilson, California. Although the data clearly show a marked decline in ozone following the 1912 eruption of Katmai, quite possibly the biggest eruption until Agung (1963) or El Chichon (1982), this event is not cited in the WMO assessment or any other recent paper of which I am aware. See F.W. Paul Gotz, "Ozone in the Atmosphere" in Compendium of Meteorology, American Meteorological Society, p. 280 (1951) and Gotz, "Das atmospharische Ozon," Beitr. Geophys., (Supp.) 1, 180-235 (1931). Gotz, in collaboration with Dobson, began the first ozone observations at Arosa, Switzerland, where the longest continuous series of such measurements have been made. Although they do not discuss the reason, Ronald Angione, Edward Medeiros and Robert Roosen show a plot depicting generally low ozone at Mt. Wilson in Fig. 2 of "Stratospheric ozone as viewed from the Chappuis band" in Nature, 261, 289-290 (1976). The plot also shows other dips in ozone. I cannot vouch for Paul Gotz's conclusions about Erebus. But, in view of his extraordinarily careful work in this field over many decades and the professionalism of the Smithsonian observers, Gotz work should not be lightly dismissed or ignored. [snip...] >Forrest Mims has >suggested that because of special conditions at the >poles, Mt. Erebus might be a potential source for some >of the Chlorine, but Parson answered him, and in my >mind demolished his argument. However, I am not an >expert in this subject so I could be wrong. In any >case, I do not believe Mims has suggested that Mt. >Erebus is the primary source of Chlorine and hence an >explanation for the antarctic ozone hole which shows >that CFCs are innocuous. My impression of Parson's response was opposite your's. > In other words I interpreted his suggestion as not >questioning the consensus view that it is wrong to >cite Mt. Erebus as the cause but only as suggesting >that there might be a small kernel of truth and it >might be a contributing source for a small part of the >Chlorine. In any case, the truth or falsity of the >claim that Mt. Erebus plays any interesting role or >not, even a minor one, should be a subject for >discussion in the peer reviewed scientific literature, >not sci.envioronment. But Erebus has been addressed in the literature. First, some background: Erebus is a stratovolcano with a peak elevation of 3794 m (see T. Simkin & L. Siebert, "Volcanoes of the World," Smithsonian Institution & Geoscience Press, 1994, p. 161). The elevation of Erebus means its emissions are closer to the tropopause for its latitude than if it were at middle latitudes. As for the scavenging of chlorine by water vapor, Antarctica is extremely dry, especially at the summit elevation of Erebus. Mt. Erebus has been in a continual eruptive state since at least 1841. Each day several eruptions occur, and photos show long streamers of vapor trailing away from the summit. Now, as I posted a few months ago on sci.env.: EREBUS, A VERY UNUSUAL AND PERSISTENTLY ACTIVE VOLCANO, IS A MAJOR SOURCE OF CHLORINE IN ANTARCTICA, WHICH IS NOTED FOR ITS EXCEPTIONALLY DRY ATMOSPHERE. CLEARLY THIS CHLORINE IS NOT REMOVED AS RAPIDLY AS IN WETTER LOCATIONS. THE SUMMIT OF EREBUS IS BELOW THE TROPOPAUSE, AND I AM AWARE OF NO MECHANISM WHICH MIGHT TRANSPORT SOME OF THIS CHLORINE INTO THE STRATOSPHERE. BUT CURRENT OBSERVATIONS HAVE YET TO COMPLETELY RULE OUT A CONTRIBUTION OF EREBUS EMISSIONS TO OZONE DECLINE IN ANTARCTICA. FOR EXAMPLE, PHILIP R. KYLE HAS WRITTEN,"SUCH SPECULATION IS NOT SUPPORTED BY CURRENT OBSERVATIONS MADE AT MOUNT EREBUS, BUT IT IS IMPORTANT THAT THE SCIENTIFIC COMMUNITY NOT DISMISS THE IDEA OUT OF HAND WITHOUT MAKING THE APPROPRIATE SCIENTIFIC OBSERVATIONS AND EVALUATIONS." ("VOLCANOLOGICAL AND ENVIRONMENTAL STUDIES OF MOUNT EREBUS, ANTARCTICA, ANTARCTIC RESEARCH SERIES, VOL. 66, AMERICAN GEOPHYSICAL UNION, 1994, P. xiv.) Kyle's comment seems as reasonable now as when this was posted. [snip...] Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.energy,sci.environment,talk.environment Subject: Re: funding science Date: 26 Feb 1996 02:37:49 -0500 Rich Puchalsky (richp@upx.net) asks a highly relevant question re. the effect of clouds on UV-B, which I will get to below (see also "UV-B vs Clouds" under sci.env): >FMims (fmims@aol.com) wrote: >: Len Evens wrote (in part): >: >Might I humbly suggest that Forrest Mims might also make >: >mistakes. Indeed, it is even possible that he in entirely >: >in the dark about some issue, including ones he comments on. : I have posted numerous comments in sci.env regarding : the ozone layer, UV-B and the atmosphere's optical : : depth. If Len Evens or any others have noted : any errors in these posts (which can be retrieved : from various net archives), I will immediately : correct them. >I, for what it's worth, disagree with Mims about many >policy and political issues. For instance, I think >the complete CFC ban is good policy while Mims has >stated that he thinks recycling might have been >sufficient to prevent release of CFCs from fixed air >conditioning facilities. As another example, I tend >to be more blase/sceptical than Mims about claims that >various scientists have been unduly punished by >politicians for their views or that various research >plans have been unduly unfunded because of political >pressure. But these disagreements are completely >unrelated to the _science_ involved in the matter. >Mims publishes in peer-reviewed journals and is a >recognized expert in his sub-specialty. While Puchalsky and I may differ over some of the policy, I'm glad that we can agree on some of the science. [deleted comments re. scientific consensus...] >Of course, certain propagandists will pretend to be >scientists in that field so that they can support >their own politically-motivated views. They can be >easily distinguished, as they don't publish in the >peer-reviewed literature and they aren't really >familiar with the scientific evidence that they're >arguing against. Instead, they focus on reaching the >public directly, and the scientific quality of their >work is generally very shoddy in every respect. I have accumulated a file of such material. >Mims has always stated the observations motivating his >views, which he publishes, and appears to be familiar >with the work that others have done. >So, having made it clear why I regard Mims differently >than, say, Thomas Gale Moore, I'll proceed on to my >one scientific disagreement with Mims' posts, as he >invites people to do above. I'm not a scientist, so I >ask those who are to humor me if I make an obvious >error. >My primary disagreement is that Mims often talks about >variation of ground-level UV-B due to clouds. For >instance, he has stated that scattering from clouds >can increase UV-B at his detector. I don't see why >this should matter, since any particular UV-B photon >scattered into the detector would have otherwise hit >the Earth somewhere else. In effect, the cloud might >act as a giant magnifying lens of sorts, which might >have bad consequences biologically for anyone standing >directly under the lens for some period of time, but >the overall amount of UV-B reaching the surface would >not change. When Mims discusses this, he often seems >to refer to the UV-B level changing in a way that >implies that the level is changing in a broader sense. Puchalsky asks an important question, and here is posted a brief response. On a new sci.env thread ("UV-B vs Clouds") I will post some background on how I began studying the effects of clouds on UV-B plus give some actual measurements. My observations from South Texas since 1989 show that, during summer, certain clouds can cause UV-B increases which far exceed any changes caused by summer variations in ozone. Certain very bright, white clouds (usually cumulus and, especially, cumulus congestus; somerimes alto-cumulus) can efficiently scatter UV, visible and near-IR wavelengths very efficiently. A person who notices such a cloud near the Sun, will usually measure a transient increase in sunlight at all wavelengths. However, should he cloud block the Sun, there will be a transient decrease at all wavelengths. Thus the enhanced UV-B (and other wavelengths) caused by scattering from the sides of such clouds is balanced by the absorption caused by the same clouds. There is no net overall increase in the UV-B but rather a redistribution of what is there already. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: UV-B vs Clouds Date: 26 Feb 1996 02:37:50 -0500 Rich Puchalsky asked an important question about the effect of certain clouds on UV-B., which I briefly answered elsewhere (see "Funding Science" under sci.env). This repeats that reply, adds some background on how I first learned about the effects of clouds on UV-B, and gives some actual measurements. My observations from South Texas since 1989 show that, during summer, certain clouds can cause UV-B increases which far exceed any changes caused by summer variations in ozone. Certain very bright, white clouds (usually cumulus and, especially, cumulus congestus; sometimes alto-cumulus) can efficiently scatter UV, visible and near-IR wavelengths very efficiently. A person who notices such a cloud near the Sun, will usually measure a transient increase in sunlight at all wavelengths. However, should he cloud block the Sun, there will be a transient decrease at all wavelengths. Thus the enhanced UV-B (and other wavelengths) caused by scattering from the sides of such clouds is balanced by the absorption caused by the same clouds. There is no net overall increase in the UV-B but rather a redistribution of what is there already. I have collected many measurements (complete with all- sky 360 degree color and/or b&w photos) showing this phenomenon. In my experiences in Texas, New Mexico, Colorado and Hawaii, enhanced UV-B caused by scattering from the sides of clouds often lasts long enough for erythemal effects and significantly exceeds UV-B increases caused by ordinary ozone changes. This is because ozone is usually very stable during the summer months when erythemal effects are of concern. (Ozone variations are usually much greater in the late fall, winter and early spring.) Based on my measurements in Maryland, Washington, DC, and Brazil, thick haze and smoke eliminate the cloud scattering effect entirely. When I began measuring direct UV-B at 300 nm through a collimator with a 2 degree field of view (the Sun subtends 0.5 degree) in the fall of 1988, I often noticed a sharp spike in the UV-B when a cloud passed near the Sun. To check this out, I bought a $179 telescope tracker and a $1200 chart recorder and began measuring direct UV-B in real time for entire days over a period of months. This study conclusively showed that clouds near the Sun cause a transient increase in direct UV-B, but I didn't then think the effect was significant since it probably didn't cause a major effect on the total sky UV-B (the sum of the direct UV from the Sun and that scattered by air molecules, clouds, haze, dust, etc.). Plans for the radiometer used in this work were published in SCIENTIFIC AMERICAN ("The Amateur Scientist," Aug 1991). For an ongoing UV study during my annual Hawaii trip (to teach a class on experimental science for humanities majors at the University of the Nations) in the spring of 1994, I designed a miniature UV-B data logger. This little instrument can store up to 1800 samples at programmable intervals ranging from 1 per 0.5 sec. to one per 4 hours. I placed 14 of these data loggers all around the Big Island for a 3-day test. All were programmed to switch on at 6:00 am the next morning and then run for 3 full days. (How the loggers were concealed in lava, sometimes at night, and then recovered is a story of its own.) My intent was to study the variation of UV-B from sea level to the Mauna Loa Observatory (3.4 km above MSL). But what surprised me most was that some of the loggers showed very significant and sustained spikes of up to 27 minutes in the midday UV-B. After I traced the phenomenon to cumulus clouds near the Sun, it was obvious that my earlier conclusion that the cloud effect wasn't significant was clearly in error. I immediately called John Frederick at the University of Chicago. Frederick is a highly recognized authority on the effects of clouds and UV, and his advice played a key role in my decision to measure direct UV-B. Frederick's models (at that time) did not allow for an increase in UV, even though he had long suspected that clouds could cause increases. Frederick studied my data, and joined me in a note to NATURE, which was published on 22 Sep 94. A peer reviewer noted that while the phenomenon was well known to the limited number of workers who make such measurements, he was unaware of a publication reporting it. Last spring, I repeated this work with modified data loggers capable of detecting UV-B, visible sunlight (500 nm) and near IR (1020 nm). This time I stayed at my detector array with a camera equipped with a fisheye lens. The very first day, low cumulus clouds swept over Mauna Loa Observatory just past noon and caused significant (ca. 25%) increases in UV and even much greater (ca. 40%) increases at 500 nm. Although I had no way of knowing what the detectors were seeing, I made a number of full-sky photos at the time. The result is a good set of photos AND data that show the phenomenon very nicely. When time permits, I'll prepare a paper on these results. Meanwhile, allow me to share a few results from my 9- year old daughter's (Sarah Anna Mims) latest science fair project. I loaned Sarah a Vital Technology BW-10 UV-B meter, which she used much of last summer (alongside a $115,000 or so EPA Brewer spectrophotometer and a Solar Light 501 Biometer). She used a disposable Kodak camera to make sky photos each time she measured the UV-B. Ozone was fairly constant all summer. Here are some typical results copied from actual photos on her poster, which she has just laid on the floor next to my chair: Date Sky UV-B Index 28 Jun totally clear 7.0 03 Jul totally clear 7.6 04 Jul clouds near Sun 7.8 04 Aug clouds near Sun 7.9 29 Jul nearly overcast 4.0 30 Jul nearly overcast 4.2 The increases caused by clouds near the Sun that Sarah measured are not as great as those I regularly measure. This is probably because the BW-10 has much more UV-A response (ca. 25%) than my instruments (<1%) and its cosine response is not as good. What is fascinating about her project is that I have yet to see anyone actually publish sky photos that show the cloud effect. Incidentally, Sarah also measured UV-B atop Mount Evans, the highest paved road in the U.S. (ca. 4.4 km). She found that UV-B atop Mount Evans on a July day is only slightly higher than what we observe in Texas for much of the summer. (I got similar results.) The point of all this is that simple equipment can be used by a patient observer to make worthwhile findings. I am now writing new papers about some of my instruments in the hope others will build them. If readers or contributors to this forum would like to begin making their own measurements, I will try to find time to post some tips. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) Newsgroups: sci.environment From: roosen@netcom.com (Robert Roosen) Subject: Re: Pinatubo and Ozone--a Question Date: Fri, 1 Mar 1996 02:54:24 GMT FMims (fmims@aol.com) wrote: : John R Christie (chejrc@lure.latrobe.edu.au) suggested that the visible : (Chappuis) and UV-B (Huggins, I believe) ozone absorption coeffcients are : equally susceptible to temeprature changes. This is not correct. It is : well established that the Chappuis band is not sensitive to temperature : changes, while the near UV-B bands are. : This would appear to make the Chappuis band (which has two nearby peaks at : about 610 nm in the orange) better suited for measuring ozone. The : limiting factor here is that the Chappuis band absorbs only around 10% of : that absorbed by the UV-B. (10% is generic since the absorption in the : UV-B increases sharply as wavelength falls.) : Forrest M. Mims III : Sun Photometer Atmospheric Network (SPAN) Yes, the Chappuis band is a weak band. At its peak it reduces the solar energy by three or four per cent. This requires astronomical accuracy (better than one per cent) in the radiometer in order to separate the relatively small effect due to ozone. Another advantage of using this weak band is that the absorption remains linear with a large range of air mass. In the UV, the Forbes effect becomes important by air mass 2 or three and a real stumbling block near the horizon, where a substantial component of the scattered UV light is found. In general, reduction of normal incidence measurements in the visible is much more straightforward than UV measurements, which require all sky scattering models filled with assumptions. Such models were not really very good before the mid-1960s, which may be one reason why Bojkov's recent paper on trends does not attempt to include data before that epoch, even though Dobson was making measurements since the 1920s. Robert Newsgroups: sci.environment From: roosen@netcom.com (Robert Roosen) Subject: Re: Demonizing S. Schneider (was Re: CFCs in the atmosphere (was Re: W Date: Sat, 2 Mar 1996 08:20:54 GMT Steve Emmerson (steve@unidata.ucar.edu) wrote: : roosen@netcom.com (Robert Roosen) writes: : > Schneider is a theoretician. As such he is able in good : >conscience to ignore data sets that disagree with his theories and to : >extrapolate existing data way beyond what they are capable of telling us. : Possibly. In order to convince me, however, would you please provide : a reference to a peer-reviewed paper that indicates that Schneider has : ignored data sets that disagree with his theories. : Would you also please provide a reference to a peer-reviewed paper that : indicates that the IPCC Working Group I has extrapolated existing data : way beyond what it is capable of telling us. That is easy. Here are ten peer reviewed papers that present a much different view than Schneider's. Now I challenge you to provide one reference in which Schneider uses the information provided in these papers. Publications Related to Weather and Climate by Robert G. Roosen, PhD 1. Worldwide Variations in Atmospheric Transmission: 1. Baseline Results from Smithsonian Observations. Bulletin of the American Meteorological Society 54, 307-316 (1973). With RJA and C. H. Klemcke. (RJA is Ronald J. Angione.) 2. Possible Relationships Between Solar Activity and Atmospheric Constituents. in "Possible Relationships Between Solar Activity and Meteorological Phenomena" W. R. Bandeen and S. P. Maran, eds. NASA SP-366, 149-154 (1973). With RJA. 3. Drought Prediction. Science 186, 393-394 (1974). With RJA. 4. Climate Prediction. Bulletin of the American Physical Society Series II 20, 93 (1975). 5. Earth Tides, Volcanos and Climatic Change. Nature 261, 680-682 (1976). With R. S. Harrington, J. Giles and I. Browning. 6. Stratospheric Ozone as Viewed from the Chappuis Band. Nature 261,289-290 (1976). With RJA and E. J. Medeiros. 7. Variations in Atmospheric Water Vapor: Baseline Results from Smithsonian Observations. Publications of the Astronomical Society of the Pacific 89, 814-822 (1977). With RJA. 8. Use of the Chappuis band for determination of modern and Historical Ozone Levels. Final Report to NASA/Langley Research Center on Grant NSG 1430 (1981). With RJA. 9. Baseline Ozone Results from 1923 to 1955. Journal of Climate and Applied Meteorology 22, 1377-1383 (1983). With RJA. 10. Atmospheric Transmission and Climate: Results from Smithsonian Measurements. Bulletin of the American Meteorological Society 65, 950-957 (1984). With RJA. Of course, Schneider also completely ignores the original Smithsonian APO work (Annals, vols. 1-7 and hundreds of other publications.) Robert From: fmims@aol.com (FMims) Newsgroups: sci.environment,talk.politics.libertarian Subject: Re: Why are they lying to us about CFCs?? Date: 4 Mar 1996 00:49:02 -0500 Josh Halpern, responding to my earlier post, wrote (in part): >: Kyle's comment seems as reasonable now as when this was >:posted. >Yes, but folks on some other side might say, this is merely >a plea for more grant funds so that he can continue his work >on measuring Erebus' output, while we really need to spend >the money setting up a UV monitoring station. While I agree some may make such a claim about Kyle, it is impossible to detect anything other than objectivity in his work. As for the "other side," since at least 1988 it appears that the principle advocates of the ozone paradigm have not been in favor of a ground-based UV-B network. For example, last fall I was personally criticized by Sherwood Rowland for advocating a global UV-B network. (When I was informed of this, I asked why, and Rowland sent an e-mail apology.) Forrest M. Mims III Sun Photometer Atmospheric network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: HELP! UV radiation at night Date: 9 Mar 1996 10:58:26 -0500 Ralph Cutter asked about night levels of UV. The moon reflects enought UV from the Sun to make ozone measurements possible at night when the moon is bright. Thus there is some UV--although very little--when the moon is visible. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment,talk.environment Subject: Re: CFCs (was re: what about 25000 nuclear reactors) Date: 10 Mar 1996 00:34:28 -0500 steve@unidata.ucar.edu (Steve Emmerson) writes: >eggsoft@sydney.DIALix.oz.au (Greig Ebeling) writes: >>In the absence of PSCs (at mid-latitudes), the ClO never forms, and so ozone >>depletion does not take place there. >The Nature paper by Russel et al. provides evidence that ozone depletion >does occur at mid-latitudes due to CFCs. I read the Russel et al. paper and the accompanying commentary. Perhaps I missed something, but can you please point me to the portion of the paper that asserts that CFCs cause ozone destruction at mid-latitudes? I do not recall seeing any correlation of the abundance of CFCs and/or their byproducts with the abundance of ozone. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: CFCs Date: 10 Mar 1996 01:37:55 -0500 Bruce Hamilton wrote (in part): >It should be noted that the producers were not alone in their >skepicism, Jame Lovelock, who invented the cfc-measuring >Electron Capture Detector and who first reported that CFCs were >pervasive in the atmosphere ( were not being rained out as most >other chemicals were ), was also publically highly sceptical of >the Rowland and Molina hypothesis. Fred Singer, who is also a skeptic of the CFC-ozone destruction model, proposed long ago that increasing methane could cause ozone decline. Lovelock has proposed the same thing and even suggested that increasing methane could have caused the ozone hole without CFCs. Others have proposed that increased stratospheric water vapor can cause significant ozone destruction. Time will tell: CFCs are being phased out while methane and water vapor continue to increase in the stratosphere. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: the sun and climate Date: 12 Mar 1996 09:04:13 -0500 Paul Farrar wrote about solar effects on climate. I would like to add that fluctuations in ozone can have an important effect on temperature. Although ozone absorbs best in the UV-C and UV-B, it also absorbs in the Chappuis band centered at 2 points at about 590 and 610 nm in the yellow and orange part of the spectrum. The Chappuis band extends across much of the visible spectrum. Since the irradiance of sunlight peaks at about 500-550 nm, absoprption by the Chappuis band, although less than in the UV-C and UV-B, can play a significant role in moderating the sunlight that reachers the surface. Less ozone means more warming. Incidentally, total ozone over South Texas since January has returned to levels not seen since the early 1980's. On 9 Mar 96, total ozone reached a record (for that day) of 363 Dobson units, the highest measured here since before Pinatubo erupted in 1991. Ozone last summer was very low, and during Nov 94 was the lowest ever measured in North America to that time. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Publishing criticism Date: 12 Mar 1996 19:46:14 -0500 James Acker responded to my comments on peer review. The media which permits this exchange of opinions is even now causing major changes in peer review that will hasten the publication of important findings. See the excellent news article on this in NATURE, 29 Feb 1996 (vol. 379, p. 758). As for my rejected paper on significant ozone decline following Pinatubo, the fact remains that the peer reviewers claimed the finding was not possible. It was not long before they were proved wrong, but the paper was never published. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment,talk.environment,alt.catastrophism Subject: Re: CFCs (was re: what about 25000 nuclear reactors) Date: 12 Mar 1996 19:56:28 -0500 Rich Puchlasky wrote about the contrarian point of view on ozone depletion (in part): >You're contradicting the mainstream ozone theory, which has a tremendous >amount of evidence supporting it. Almost all scientists in the field >are rightly convinced by this evidence. Puchalsky is correct about ozone depletion in polar regions that involve heterogenous chemistry suggested by Solomon in which reactions take place on the surface of particles in PSCs and on ozone decline elsewhere where volcanic aerosols provide a suitable surface. The major remaining controversy is the gas-phase chemistry proposed by Rowland and Molina. I was present at the 1992 Quadrennial Ozone Symposium when Susan Solomon stated flatly in a keynote speech that, "Gas phase chemistry is dead." Based on the lack of public replies and the abundance of private comments from scientists who study ozone in response to my previous questions regarding publications on the correlation, if any, of the abundance of chlorine and ozone at middle latitudes and the fact that, in the absence of volcanic aerosols, ozone decline in this region should be based on gas-phases processes, I conclude that no such correlation has been demonstrated. This is also apparently the conclusion of the 1994 WMO assessment, and it is definitely the conclusion of ozone scientists who have contacted me. None of this rules out the impact of ozone-depleted air from polar regions drifting over middle latitudes and causing episodic low ozone. This phenomenon has been well documented in the literature, and a recent paper suggests it contributes to the lower abundance of ozone in the Southern Hemisphere. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: CFCs Date: 13 Mar 1996 08:57:02 -0500 "Mark A. Friesel" <mfriesel@beta.tricity.wsu.edu> wrote: >On 10 Mar 1996, FMims wrote: >> Bruce Hamilton wrote (in part): >> >....del >> >> Fred Singer, who is also a skeptic of the CFC-ozone destruction model, >> proposed long ago that increasing methane could cause ozone decline. >> Lovelock has proposed the same thing and even suggested that increasing >> methane could have caused the ozone hole without CFCs. Others have >> proposed that increased stratospheric water vapor can cause significant >> ozone destruction. Time will tell: CFCs are being phased out while methane >> and water vapor continue to increase in the stratosphere. >> >> Forrest M. Mims III >> Sun Photometer Atmospheric Network (SPAN) >> >Let's say that CFC's contribute to atmospheric ozone depletion. Let's >say water vapor and methane do likewise. Phasing out CFC's while >increasing vapor and methane could result in only a minor change in ozone if >any, and small changes could be very difficult to identify. A result >that no significant change in ozone has been noted after replacement of >CFCs by methane and water vapor could be interpreted as meaning that none of >the above appreciably affect atmospheric ozone. The experiment, in this sense, >is not definitive and may be misleading. Another problem is that the monitoring of important chlorine and bromine sources in the stratosphere is simply inadequate or non-existent. Biomass burning, a significant source of methyl chloride and methyl bromide, has increased at exponential rates in some regions since the late 1970's. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Publishing criticism Date: 13 Mar 1996 19:58:25 -0500 James G. Acker responded to my comments on peer review (in part): [Mims wrote:] >: As for my rejected paper on significant ozone decline following Pinatubo, >: the fact remains that the peer reviewers claimed the finding was not >: possible. It was not long before they were proved wrong, but the paper was >: never published. > You did see that in my response where I said that reviewers can >be wrong, didn't you? > Out of curiousity, did you try to resubmit the paper to a different >journal after the rejection from the first journal? If you didn't, >my question does not constitute criticism. I don't think that your >personal livelihood is as tied to the necessity to publish as it is for >many academic scientists, so you might not have tried again. I didn't resubmit elsewhere since by the time the lengthy review process was completed I learned others with far more resources at their disposal had also detected post-Pinatubo ozone decline. As you probably know, dozens of papers were eventually published and major sessions in various conferences and meetings were dedicated to the ozone decline that followed Pinatubo. [snip...] > It is my perception (based on very limited data) that you tend >to focus your efforts on the big-name journals such as _Science_ or >_Nature_, which due to both their prestige and the volume of submissions, >have a much higher rejection rate. Actually, I have written articles for more than 70 publications, a dozen or so being peer-reviewed. Some magazines are much tougher to crack than SCIENCE and NATURE. As an aside, none of the peer-reviewed journals has ever asked to see the instruments I made to collect the reported data. But I have sometimes had to produce instruments or circuits for non-peer reviewed magazines when I claimed some degree of novelty. Some magazines not known for being peer reviewed sometimes use peer review. An editor at SCIENTIFIC AMERICAN told me that my letter on haze and UV-B (Sep 1995) was peer reviewed. > I would think that their >prestige also makes them very conservative, as they wouldn't want an >egregiously wrong paper to get in very often. That's why _Nature_ >went to such extraordinary lengths regarding Benveniste's work. >Since, apparently, all that you submitted was observational data with >no discussion of possible cause (CORRECT me if I'm wrong, please!), >then with no theoretical underpinning the reviewers seemed to >side with the likelihood of anomalous observations. The data were from 2 ground-based ozonometers and from Nimbus-7/TOMS (obtained through the former NSSDCA link). This was well before the TOMS calibration began to drift, and ozone retrievals from TOPS and TOMS had a very high correlation. [snip...] >You definitely measured effect. It seems to me that the >reviewers were questioning whether you had cause. If you did, >then I'm way off base. Did you? I have not looked at the reviews recently, but I distinctly recall that one was especially adamant in claiming the improbability of ozone decline following a volcanic eruption. As I have posted here and elsewhere, various peer-reviewed sources show an ozone decline following the eruption of Katmai. When I mentioned this to a leading atmospheric chemist, he ridiculed both the prospect of volcanic ozone decline without the presence of anthropogenic chlorine required by current models and the primitive nature of the instruments, about which he was completely unaware. This is unfortunate, for the instruments used by the Astrophysical Observatory of the Smithsonian Institution were certainly not primitive. Indeed, they measured the solar constant to a high degree of accuracy over many decades. Preconceived notions such as those by this leading scientist harm the practice of science, especially when they lead to the rejection of new findings. I close by noting that some famous rejected papers were written by scientists or engineers who were simply peerless. Consider Theodore Maiman, whose seminal paper on the first working laser was rejected by a leading journal of physics before NATURE published it. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: the sun and climate Date: 14 Mar 1996 09:52:37 -0500 14 March 1996 Joshua Halpern suggests that my comments about the optical effects of ozone mix apples and oranges, when the effects I listed are both well established in the literature and correct. The Apple: Ozone is, as Halpern agrees, a greenhouse gas. The Orange: Besides its steep absorption in the UV-B, ozone absorbs light across the visible spectrum from 500 to 700 nm, peaking in the orange near 610 nm. Halpern wonders if the 2% absorption of visible sunlight by ozone he found in a reference might be high. It is not. Though this topic is discussed in various papers, it appears not to be well known among those who study the relationship of ozone and UV-B. According to "Prediction of Solar Radiation on Inclined Surfaces; Series F: Solar Radiation Data" (S. K. Page, ed., D. Reidel Pub. Co., 1986), the direct beam absorption by ozone (380 DU) at 550 nm varies from 1% at an air mass of 1 (sun at zenith) to about 3.5% at an air mass of 4 (sun 14.5 degrees above horizon). (For this range of values, the air mass, m, is the reciprocal of the sine of the Sun's angle over the horizon.) Consider this observation by Angione, Medeiros and Roosen in "Stratospheric ozone as viewed from the Chappuis band (NATURE, 261, 289-290, 1976): "...because of its location near the peak of the solar energy spectrum, the Chappuis band [i.e. the visible absorption band] absorbs on average ~2% of the total solar flux at midlatitudes (11). Thus, for example, if solar variations and transport combine to produce an increase in stratospheric ozone of 25% over a given mid-latitude station, the total solar energy reaching the troposphere above that station would be decreased by ~0.5%, an amount of importance to both weather and climate....Because of the longer slant path lengths [i.e. higher air mass], the effect is much larger in the polar regions." The absorption of ozone in the Chappuis band can be readily observed using a simple Sun photometer fitted with filtered detectors at 600 and 700 nm. The changes are especially obvious when there are wide swings in ozone, as happened over South Texas recently when ozone reached an unusually high (for this region) 363 Dobson units around the same time portions of the Arctic were experiencing record ozone lows. Time precludes a more thorough discussion of this very interesting topic. Thus I close by standing by the points in my original comments. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) SPAN has MicroTOPS ozonometers in Paraguay, Togo, South Africa, 4 Pacific islands, Falkland Islands, California, Maryland, Colorado and Texas. New sites are slated for Central Equatorial Africa and Hawaii. SPAN operators include students and their teachers, missionaries and professional scientists. From: fmims@aol.com (FMims) Newsgroups: sci.environment,sci.geo.meteorology Subject: Re: 50 percent ozone loss over Britain Date: 5 Apr 1996 10:27:31 -0500 With regard to the recent ozone decline over portions of Europe, I would like to point out that TOVS observations show ozone at pre-Pinatubo levels over middle latitudes in the Northern Hemisphere. SPAN ozone measurements in South Texas and Santa Barbara, CA since January 1996 show ozone at levels not seen since the early 1980's. The UV-B index at South Texas at solar noon now exceeds 8 on days when the Sun is visible. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment,sci.geo.meteorology Subject: Re: 50 percent ozone loss over Britain Date: 7 Apr 1996 20:47:57 -0400 Jim Scanlon wrote in response to Mims: >> With regard to the recent ozone decline over portions of Europe, >> I would like to point out that TOVS observations show ozone at >> pre-Pinatubo levels over middle latitudes in the Northern Hemisphere. >What do you think this means ? Perhaps that ozone decline is prpblematic >only where there are colder than average temperatures. I am not sure what >to include in "middle latitides". The ozone decline reported so far seems >to go from 50 North (southern England} north. This is approximately the >limit of the springtime Antarctic ozone hole. There have been previous major ozone declines over the arctic. They can be seen in the TOMS record. Also, some ozone numbers for Asia are to be considered only with care if measured with the Russian M-124. I have had much to say about this instrument in prior posts. I used an M-124 for 2 years. It simply does not give sufficient ozone when the Sun is low in the sky (as in winter). >> SPAN ozone measurements in South Texas and Santa Barbara, CA >> since January 1996 show ozone at levels not seen since the early 1980's. >I assume you mean that they are higher than they have been for some time. Yes. If we consider only the Nimbus-7/TOMS record since 1978, then ozone here is completely "normal." Of course this may change. >> The UV-B index at South Texas at solar noon now exceeds 8 on days when >> the Sun is visible. >Would you please provide a brief explanaton of what this means? I have >trouble remembering. It simply means the UV here is rather normal. Actually, since ozone here is pleasantly higher than in past years, the UV is somewhat lower than last year at this time. Here in South Texas the UV index will range from 9.5 to 11.5 all summer. In Hawaii it may reach 12 to 13 (at sea level) and higher at Mauna Loa Observatory (elev. 3.4 km). Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment,sci.geo.meteorology Subject: Re: 50 percent ozone loss over Britain Date: 9 Apr 1996 18:19:00 -0400 Jim Scanlon wonders why there have been no reports in the general media on UV-B during the recent ozone minimum over northern Europe, especially since the affected regions are well equipped with instruments. When ozone reached a record low for the SE U.S. in Nov 1994 (220 Dobson units at South Texas), UV-B measured by various instruments showed only a very modest increase. This is because the angle of the Sun was such that the UV had to penetrate the equivalent of about 1.5 ozone layers. The areas of Europe affected by the recent ozone anomoly also had very low Sun angles. Therefore, while UV-B most certainly would have increased, the increase would not have exceeded summer levels. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Dust to dust Date: 17 Apr 1996 02:33:30 -0400 Jan Schloerer wrote about the optical thickness of dust. This is a fascinating and very important topic. I would like to add that satellite optical depth measurements are limited in accuracy. SAGE II does not have daily global coverage and it works best only in the stratosphere. The AVHRR works best over water. It is also subject to underestimating optical depth--as I demonstrated in 1992-3 by comparing AOT data from my site and AVHRR data from over the nearby Gulf of Mexico. Jan Schloerer also wrote: >Forrest Mims might wish to add ground-based UV >as a third example. What about a letter to Nature ? ;) Actually, I am just completing a short paper on this right now. My emphasis is on very significant measured reductions in UV-B during the burning season in Brazil. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.geo.meteorology Subject: Re: 50 percent ozone loss over Britain Date: 17 Apr 1996 02:34:32 -0400 Jim Wise wisely asks: >As a middle school earth science teacher, what do I tell the kids? >*Record low ozone levels recently recorded over Europe True. It was a transient event. Some of the ground data is quite good; some is based on instruments of highly questionable accuracy. >*UV levels depend on sun angle (thus season and latitude) True. When record low ozone occurred over the SE U.S. in November 1994, the Sun angle at noon was so low that the UV-B increase was insignificant. (I wrote about this in EOS in March 1995.) You should also be aware that during summer over most of the Eastern U.S., haze has much more influence on UV-B than ozone. I have found that sulfate haze over Washington, DC, for example, reduces UV-B by from 12% to 30% in July. >*Importance of UV levels reported depend on whether UVA or UVB >measured UV-A is unaffected by ozone changes. UV-B is more biologically active than UV-A. >*Some scientists feel disgraced that more UV measurements have >not been made Many UV scientists think it is disgraceful that UV-B is not properly monitored by a global network of compatible instruments. The same can be said of the vertical clarity of the atmosphere (optical thickness). >I have been teaching this unit based on NASA lesson materials >and am about to teach it this next week. I want to be accurate. Having been asked to review some school books about ecology and the environment which contained very serious flaws, it is reassuring to know that at least some teachers are concerned about presenting accurate information. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) >Jim Wise >Parker Middle School >Edinboro. Pa. 16412 From: fmims@aol.com (FMims) Newsgroups: sci.geo.meteorology Subject: Re: 50 percent ozone loss over Britain, also Contrails thread Date: 22 Apr 1996 10:12:00 -0400 In message dated 04-10-96 CLAIRE GILBERT wrote : > So, are you Woody and Forrest saying that ozone loss is NOT significant > if it doesn't directly affect us with UV-B? I wrote only that sharp declines in the wintertime ozone at northern latitudes have minimal effects on UV-B due to the very low Sun angle. This is based on actual observations and a peer-reviewed paper (F. Mims et al., EOS, March 1995). Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Record low ozone over Hawaii, winter 1994-5 Date: 7 Jul 1996 22:13:18 -0400 Bruce Hamilton writes that New Zealand might discontinue a UV-B monitoring network that, I gather, uses broadband instruments. This is quite unfortunate, as such instruments are generally very reliable and, based on my working experience with a scanning radiometer, provide excellent erythemally-weighted data. Perhaps Bruce Hamilton could post an address where polite letters of support for this program can be sent. Thank you. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.environment Subject: Re: Record low ozone over Hawaii, winter 1994-5 Date: 7 Jul 1996 22:21:31 -0400 I remember reading some of these articles. It is a fact that Harper was fired. Scott Nudds wrote about the firing of Happer from DOE (in part): > It is pure speculation that he was fired for calling for UV-B measurements. > What would be required to prove Andrew Russell's statement would be an >admission from Gore, a Memo stating the motivation, or substantial ><evidence>, [not speculation], that provides the motivation for the >firing, as well as a trail connecting the firing with Gore. > Have you seen anything <more> than <speculation> on this matter? I > I have seen speculation, but no evidence. When time permits I'll look for the old posts on this. As I recall, the articles in the science press were rather specific about Happer's troubles over calling for UV-B measurements. As for V.P. Gore, in July 1993 I sent him two faxes re. record high UV-B (and record low ozone) in Texas. He never replied. I then called two members of his staff who told me that Gore might be interested in record high UV-B. They asked to see my faxes and said they would pass them to Gore. I never heard from them again nor did I ever hear from Gore. My data were eventually published in GRL, and the EPA sent me to Japan to give a paper on the data at an international UV-B conference as one of its U.S. representatives (though I did this work on my own). A few months later I was invited to Washington by the EPA to give a talk on my measurements. They arranged a meeting with some Con- gressional staffers who apparently played a supportive role in the EPA-NOAA UV-B forecast operation. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: fmims@aol.com (FMims) Newsgroups: sci.geo.meteorology Subject: Re: Ozone hole <-> defoliation corellation? Date: 9 Jul 1996 19:59:56 -0400 Thanks to Robert Parson for pointing out that methyl bromide is a significant byproduct of biomass burning. I had this in mind when I mistakenly typed methyl iodide. To place some perspective on this from an anecdotal viewpoint, there were days last August and September when fully half of Brazil and much of Bolivia, Paraguay, and northern Argentina were under a thick layer of smoke from the burning of savannah and rain forest. It was truly an amazing site to fly many hundreds of kilometers and see smoke extending from horizon to horizon. The smoke was clearly visible on satellite images as well. On some days at Cuiaba, I found that 40% of the green light (500 nm) was attenuated. Forrest M. Mims III Sun Photometer Atmospheric Network (SPAN) From: rparson@spot.Colorado.EDU (Robert Parson) Newsgroups: sci.environment Subject: Re: Ozone hole=storm in a teacup Date: 5 Dec 1996 02:05:48 GMT Greig Ebeling's posts in this thread contain many mistakes and many fallacious assertions. I am collecting my responses into a single post. In article <57d02n$4lh$1@sydney.DIALix.oz.au> Greig Ebeling <eggsoft@sydney.DIALix.oz.au> wrote: >My initial impression was that research into ozone depletion seemed >to be conducted in an unscientific manner. The original observation >of Antarctic ozone depletion immediately generated theories involving >human disruption of the environment, and little interest was shown in >investigating the chemistry, and dealing with the causes (if possible) >when the theories were proven valid. This is completely wrong. During the first two years after the discovery of the ozone hole was announced, a *lot* of effort was devoted to hypotheses that made no reference to halogen chemistry. Many of the scientists whose names are now associated with the "Standard Model" of Antarctic Ozone Depletion, such as Mark Schoeberl and Jerry Mahlman, were originally committed to purely dynamical theories. They published thier hypotheses in the scientific literature (many of them can be found in the last issue of GRL for the year 1986) and made definite, testable predictions. When their predictions were refuted they changed their positions. (Yes, in spite of Kuhn et al., in science people really do change their minds when confronted with contrary evidence. Not always, but often.) >The fact that the investigation seemed from the outset to be a witch >hunt for CFCs, that Dupont's patent on CFCs had recently expired, Urban legend which has been refuted several times on the net. The original patents expired long ago. And they didn't belong to DuPont anyway. From a post by Bruce Hamilton: ------------------------------------------------------------------------- **Subject: Re: Freon R12 is Safe **From: B.Hamilton@irl.cri.nz (Bruce Hamilton) **Date: 1996/09/18 **Message-Id: <9137cc$0181f.360@HERMES> ** There were many patents for the manufacture of CFCs ** issued in the 1930s, and Kinetic Chemicals actually received theirs (June ** 1935 ) before Midgley and Henne ( July 1935 ). There were plenty of ** competitors, and, as most were process patents, they were continually ** being replaced by more efficient and less polluting processes right up ** until the 1980s. No monopoly or conspiracy. ---------------------------------------------------------------------------- > and that Dupont was funding the bulk of the research Ridiculous. Last time I checked Dupont's in-house Atmospheric Science Group consisted of about two people. The only other atmospheric science funding I can think of that has any connection to DuPont is the Chemical Manufacturer's Association, which funded some grants (awarded by an independent board of scientists on the basis of peer reviewed proposals) for research into possible tropospheric sinks for CFCs during the late 1970s, and also put some money into the AAOE mission (which was primarily supported by NASA and NOAA). In the first instance, the hope of the companies that put up the money that CMA gave out was clearly that sinks _would_ be found (they weren't). If anything, CMA was funding research that was aimed at _refuting_ the CFC-ozone link. And at the time of AAOE, DuPont still opposed CFC reductions. >was, you must agree, more than a coincidence. Indeed. It's simple fabrication. To anyone familiar with the early history of this subject, the idea that DuPont is behind it all is utterly ludicrous. DuPont was just about the most adamant _opponent_ of the Rowland-Molina hypothesis between 1974 and 1988. Go look up ~1975 issues of _Science_ or _New Scientist_ and you'll see that they took out full-page ads attacking the research. (For the most part the attacks were well-informed and based on genuine scientific questions; in my opinion they played fair but rough.) Even after the 1987 AAOE Mission and the 1988 Ozone Trends Panel report, the initial response of DuPont was to oppose reductions in CFC emissions. It was only upon urging from their own scientific staff that the executives reversed their position. >Also the Montreal Protocol, touted as a solution to the "problem" of >ozone depletion, was completely ineffective in reducing CFCs. Four >major industrialised countries (Japan, Korea, Indonesia, China) did not >sign it, and continue to use CFCs Japan signed the original protocol in 1987 and ratified it in 1988. China ratified in 1992, South Korea and Indonesia in 1992, North Korea in 1995. As of 30 June 1995, 149 nations had ratified; see gopher://unephq.unep.org:70/00/un/unep/convent/montreal/mon-rat >As , as do developing countries. The >rate of increase in CFC mixing ratios is not expected to level out >for decades. Again false. From the FAQ, Part II, * Growth Rate, pptv/yr *Year CFC-12 CFC-11 *1977-84 17 9 [Elkins et al. 1993] *1985-88 19.5 11 " *1993 10.5 2.7 " *1995 5.9 -0.6 [Montzka et al. 1996] *Methyl chloroform and carbon tetrachloride are also decreasing, while *CFC-113 has stabilized. Overall, tropospheric chlorine from halocarbons *peaked in 1995 and has begun to decline. [while the last line of the table went in sometime in 1996, I know that I put in the first three lines shortly after the Elkins et al. paper appeared in late 1993.] >My calculations suggest that the natural burden of inorganic Cl was >quite sufficient. Rowland's response seemed rather subjective, and >seemed to be based on the following: > "The measurements in Antarctica > in the late 1950s and 1960s do not indicate any loss being observed > there.See Dobson's quote in his book Exploring the Atmosphere--the amount of > ozone did not rise much during the winter, or even the early spring". > Note "rise", not "fall"." >IMO the evidence of a scientist using comparatively primitive techniques >is not strong evidence. "Primitive techniques"? Dobson spectrophotomers are still in use today. The ozone hole was discovered with one. >Also the notion that increased ozone depletion is entirely due to >synthetic organochlorides must be in doubt, since the "ozone hole" has >recently reduced in intensity, whilst chlorine levels have continued to >increase. Both Cicerone and Rowlands agreed that PSCs are both critical No, except for a temporary _increase_ around 1993, probably due to Pinatubo aerosols extending the range of the heterogeneous chemistry, the ozone hole has maintained a rather constant size and depth since since 1989. As discussed in the FAQ, this is expected since in the region where the heterogenous chemistry operates (lower half of the stratosphere, nearly _all_ of the ozone is destroyed when the hole forms.) Further incremental increases in stratospheric Cl won't influence the size or depth much, although they may increase the duration of the hole (with more reservoir Cl, the threshold for massive ozone destruction can be reached earlier in August.) >Finally, I am yet to see any evidence that ozone depletion occurs at >mid-latitudes, that it results in a net loss in ozone from year to year, Evidence and references are presented in part I of the FAQ. See also the 1991 and 1994 WMO Scientific assessments. The Executive Summary of the latter is on the Web at the NOAA Aeronomy Lab, http://www.al.noaa.gov/ Mid-latitude ozone depletion is thoroughly documented. >or that the seasonal losses cause any damage to the biosphere. What about the antarctic phytoplankton? See the Smith et al. paper, cited in Part IV of the FAQ. > (Claims that skin cancer in humans may be attributed to ozone depletion is > nonsense.) Not at all. See DeGruijl's paper in CONSEQUENCES, on the web at http://www.gcrio.org/CONSEQUENCES/summer95/impacts.html Just because the media exagerrates the effects, does not mean that the effects do not exist. In article <57jj97$qmn$1@sydney.DIALix.oz.au>, Greig Ebeling <eggsoft@sydney.DIALix.oz.au> wrote: >(2) There has always been a relatively large burden of inorganic Cl > present. >Methyl chloride (CH3Cl) comes mostly from natural (biological) sources, and >is estimated to pass from the troposphere to the stratosphere at the rate of >about 1 Mt/year. That estimate is at least an order of magnitude too large. _Total_ organic chlorine entering the stratosphere in the 1980's was around 300 kt/year, of which only ~20% was MeCl. This figure is given and cited in the FAQ, Part II, Section 4.4. > It is reasonable to assume that this flux has been >occurring, at least at this rate, for about a billion years. >Whilst there are well known natural sources of organic and inorganic chlorine, >and proven mechanisms for the transportation to the stratosphere, there are >no demonstrable mechanisms for the removal of HCl from the >stratosphere. Completely wrong - the mechanism is simply stratosphere/troposphere exchange, with a time scale of about two years. > The >argument that a drop off of HCl with altitude in the troposphere is evidence >of a low natural upward flux, may also be applied to the stratosphere in >reverse. >[From Parsons FAQ, Copyright 1995] > "...the mixing ratio of HCl _decreases_ with altitude in the troposphere, > reaching vanishingly small values at the tropopause, and then _increases_ > with altitude in the stratosphere. This rules out all processes in > which HCl slowly drifts upward from the troposphere." > >This also implies that there is no downward drift either. It most emphatically does not. *There is a sink in the troposphere.* >Consider that mixing ratio measurements for HCl from Kitt Peak go from 1.6e15 >molecules/cm^2 in 1977 to ~2.6e15 molecules/cm^2 in 1990. The source for >this is Rinland et al., J. Geophys. Res. _96_, 15523, 20 Aug 1991 (with >thanks to Robert Parsons). I assume these figures are for stratospheric >HCl only. >Assuming the above figures to be correct, then I calculate: > >HCl Mixing ratio = 2.6e15 molecules/cm^2 in 1990 [Minor quibble: this isn't a "mixing ratio", it's a column height. A mixing ratio is a mole fraction and must be integrated vertically to get a column height.] >Area of earth = 510E6km^2 = 5.1E18cm^2 > >No. molecules HCl = 1.326E34 molecules > >No. moles HCl = 1.326E34/6.02E23 > = 2.2E10 moles > >Mass of HCl = 2.2E10 * 36 grams/mole > = 7.9E11 g > = 790 kt > >Assuming that the increase is entirely from CFCs (ie avoiding the volcano >debate), the contribution from CFCs is about 2.3kt /year or less than 3% >of total Cl from CFC flux (~1-2Mt/year). >Also calculating the mass of HCl in 1977 and extrapolating backwards, the >natural burden of HCl is about 450 kt. Ebeling does not say how he "extrapolates backwards", but he has clearly made a mistake. The above figures give 490 kt for 1977, so somehow he is assuming only 40 kt anthropogenic Cl prior to 1977 which is absurd since CFC emissions had already reached their first peak before this. >Therefore inorganic Cl compound flux from CFCs is small compared to the >natural burden of HCl in the stratosphere. >Also from Parson - Copyright 1995: > > "The total amount of HF > in the stratosphere increased by a factor of 3-4 between 1978 and > 1989 [Zander et al., 1990] [Rinsland et al.]; the relative increase > is larger for HF than for HCl (a factor of 2.2 over the same period) > because the natural source, and hence the baseline concentration, > is much smaller." > >Translation: there is much more natural stratospheric HCl than HF >arising from anthropogenic sources. *MIS*-translation. The paragraph neither says nor implies any such thing. It simply says that natural HCl exceeds natural HF. In fact, the comparison between HF and HCl mixing ratios, recently carried out on a global scale by the HALOE project, demonstrates clearly that stratospheric HCl is primarily anthropogenic. See http://haloedata.larc.nasa.gov/home.html, and read the published papers. > The reasoning is that since PSCs are naturally >ubiquitous (and ASSUMED a constant factor) Not assumed. PSC's correlate closely with lower stratospheric temperatures, which have been measured at the same stations that measure ozone. See below. >2. Ozone depletion causes no biological damage. > >Ozone depletion at the poles results in insignificant UV increase, >because the sun is so low on the horizon. The FAQ documents _measured_ springtime UV in Antarctica that exceeded _midsummer_ UV in San Diego, Ca. Why was that left out? > Also the area affected is >almost entirely devoid of life larger than microbes. ^^^^^^^^ YM "whales" - HTH. :-) The Antarctic Ocean is hardly "devoid of life larger than microbes." And why were the Smith et al. phytoplankton experiments left out? >At mid-latitudes increase in UV due to ozone depletion is very low >compared to daily, seasonal and global variations. This is due to an >absence of PSCs (at mid-latitudes) and so ozone depletion only takes >place there in the presence of sulphate aerosols from volcanic activity >(which is natural). The chlorine - which is what actually destroys the ozone - is predominantly anthropogenic. And, there is a background aerosol layer in the absence of volcanic eruptions. And, ozone depletion also takes place through purely gas-phase mechanisms - this was the original Molina-Rowland process. In article <582229$fce$1@sydney.DIALix.oz.au>, Greig Ebeling <eggsoft@sydney.DIALix.oz.au> wrote: >Barry M. Schlesinger (bschlesinger@nssdca.gsfc.nasa.gov) wrote: >>eggsoft@sydney.DIALix.oz.au (Greig Ebeling) writes... >>>I disagree with this. A lot of it is anthropogenic, but quite a >>>lot existed prior to CFCs, arising from the photolysis of methyl >>>chloride. >> >>What did Rowland and Molina have to say about this particular claim? > >Rowland relies on the lack of observation by Dobson (which IMO is >anecdotal). I have not posed the question to Molina. "Anecdotal"?!! The 1956-58 results are in the published literature (reference: the Applied Optics paper cited in the FAQ, and an earlier paper: G.M.B. Dobson, "Annual Variation of ozone in Antarctica", _Quarterly Journal of the Royal Meteorological Society_, 1966, p. 549 as well.) Halley Bay has a continuous record of springtime ozone going back to 1956. The original discovery of the ozone hole was based upon comparison to this long-term record. The October means from Halley are in the FAQ, were in the 1985 Farman et al. paper, and are reproduced in practically every review article on the subject as well as textbooks. You can find data for other times of year, as well as from other antarctic stations (some of which go back almost as far as Halley) in the primary literature, or in the 1988 and 1989 WMO Scientific Assessments. By the way, Dobson didn't make the observations. He supervised them from England. >>>My point is, all the ingredients for ozone depletion existed long before >>>CFCs, so it must be a natural phenomenon.... >> >>But there is no evidence for an ozone hole before CFCs, and, as my >>earlier post pointed out, accepted ground and satellite measuremnts >>showing no hole in 1959, 1970, and 1979. > >When you say "no hole", I think you mean "small hole". No, he means "no hole." An ozone hole is a _decrease_ in total column ozone beginning in late winter or early spring. There is no such decline in the 1950's or 1960's data. It may alternatively (and somewhat more precisely) be defined as a decline in ozone concentration in the lower stratosphere. No such decline is visible in the early data. Take a look at the Newman et al. paper. cited by Schlesinger, or at Dobson's 1968 paper. >It is therefore inappropriate to assume a linear correlation between >increased inorganic Cl due to CFCs, and ozone depletion. See: M. R. Schoeberl, A. R. Douglass, S. R. Kawa, A. E. Dessler, P. A. Newman, R. S. Stolarski, A. E. Roche, J. W. Waters, and J. M. Russell III, "Development of the Antarctic ozone hole", J. Geophys. Res. _101_, 20909, 1996. They show that the development of the ozone hole in the 1980's and 1990's can be reproduced using measured increases in stratospheric inorganic chlorine and known atmospheric chemistry and dynamics. There is no need to assume any "linear correlations" (in fact, a linear correlation isn't to be expected: what has happened in the antarctic ozone hole is that the inorganic Cl reservoirs are now large enough to overwhelm the "buffering" effect of stratospheric NOx when the latter is low, and produce very high concentrations of active Cl.) >Exactly! And my calcs indicate that there WAS enough Cl, and has >been for a very long time. I have not seen any calcs or models which >suggest otherwise. The calculations are wrong in a number of respects. For one thing, they were based upon a fundamentally incorrrect picture of atmospheric dynamics (strat/trop exchange in particular.) For another, they compare annual flux of CFCs into the stratosphere with annual increase of HCl, a meaningless exercise since they do not include either the HCl sink or the subsequent behavior of the CFCs after their entry into the stratosphere. For a third, some of the numbers themselves are way off (for example, an estimate of ~1 Mt of methyl chloride per year entering the stratosphere, which is at least an order of magnitude too large.) For a fourth, additional Cl reservoirs such as ClONO2 are left out. The partitioning of Cl between HCl and ClONO2 varies with latitude and season. And so on and so forth. The budget calculation simply _cannot_ be done in this way. It is much more involved. To see how to do it correctly, read some of the papers cited in the FAQ. In particular, the papers associated with the HALOE project, cited at http://haloedata.larc.nasa.gov/home.html Since the stratospheric lifetime of HCl is about two years, it follows that the relative amounts of anthropogenic and natural inorganic chlorine reflect the relative source strengths (with some corrections due to differing photolysis cross sections, etc.) The conclusion that ~80% of the Cl now in the stratosphere is anthropogenic holds for the reservoirs and active Cl, just as it does for the source gases. >>>measurement of the natural state is not possible, and all discussion on >>>this subject is of course speculative. >>> >>No. One could assume only the natural CH3Cl and then calculate a >>model to see if and when an ozone hole can be produced. > ^^^^^ >I count this as speculative. Also, does such a model exist which counters >my claims? See above. >>And what was different in 1959, 1970, and 1979 that there was no hole >>then? The CFC model has an explanation. > >Perhaps higher than normal polar temps. It is not without precedent. Except that stratospheric temperatures have been _measured_, and there is no such trend. See pp. 117-121 of the 1989 WMO Scientific Assessment. Fig. 1.8.2-2 on p. 121 (taken from B. G. Gardiner, _Weather_ _44_, 291-98, 1989) shows that there was _no_ significant change in mean September lower stratospheric temperatures (100 mbar) over Halley between 1957 and 1987. (There is, on the other hand, a definite decline in _November_ temperatures beginning about 1980 - clearly an _effect_ of the ozone hole rather than a cause.) The idea that a decline in stratospheric temperatures might have something to do with the opening of the ozone hole is an old one - it was one of a number of hypotheses floated in 1985-86. (See, for example, K. K. Tung, _Geophys. Res. Lett._ _13_, 1308, 1986.) Once the timing of the ozone hole and of the temperature trends were clearly set out, however, this hypothesis was abandoned. (Singer rediscovered it in his 1989 _National Review_ article, but failed to notice that the temperature trend follows rather than precedes the formation of the ozone hole.) >>>It is worth noting that one of Dobson's co-workers, Marcel Nicolet, admitted >>>in a TV interview, that during the 50s and 60s, anomalous readings below >>>250 DU were not officially recorded because, said Dobson: "Noone >>>will believe them". Now this is what I call "anecdotal evidence"! A distinguished but elderly atmospheric scientist speaking from memory of what another scientist _told_ him some 35 years previously? In contrast, we have the data published in the IGY Annals at the time of the project, published again in 1966 in __Quart. J. Roy. Met. Soc._, and yet again in the 1968 Applied Optics article, which clearly show that there was no ozone hole in the late 1950's. By the way, Marcel Nicolet was not one of Dobson's coworkers. >>There were some published. > >Yes, in 1958 at the French station Dumont d'Urville, >a drop in ozone to 110 DU was measured. With an unconventional and extremely difficult (at the time) method - spectroscopic measurements of UV using stars as sources. The data is subject to large fluctuations and was already marked as questionable in the IGY Annals. It is contradicted by measurements from several other stations, as well as by the meteorological data: Dumon d'Urville wasn't even inside the polar vortex when the purported low values were measured. This is discussed in the Newman article which Schlesinger cited. >The Japanese also measured a drop during the 70s. Wrong, they measured the same drop as the Halley team, in the same time period: early 1980s. In other words, they independently discovered the ozone hole. The measurements from the Japanese station (Syowa) are on p. 8 of the 1980 WMO Scientific Assessment. You should be able to find them in J. Geophys. Res. or GRL around 1986-88. Syowa, Halley, and South Pole all show the same trend in October means. The October means at Syowa in the 1970's are rather high, in fact. Look them up. ------ Robert From: rparson@spot.Colorado.EDU (Robert Parson) Newsgroups: sci.environment,talk.environment,aus.politics Subject: Re: Ozone hole=storm in a teacup Date: 13 Dec 1996 02:46:41 GMT In article <58l6jt$spd$3@coffee.DIALix.COM>, Greig Ebeling <eggsoft@sydney.dialix.oz.au> wrote: >>>IMO the evidence of a scientist using comparatively primitive techniques >>>is not strong evidence. >> >> "Primitive techniques"? Dobson spectrophotomers are still in use today. >> The ozone hole was discovered with one. > >COMPARATIVELY primitive. Compared to TOMS. Admit it Robert, before >TOMS there was considerable doubt the accuracy of spectrophotomers. Precisely the opposite is the case. TOMS is actually calibrated against Dobson (or used to be). Errors in the early TOMS estimates were identified by comparison with the Dobson measurements. It took a long time for all the bugs in TOMS to be worked out. TOMS complements Dobson in that it provides global coverage. It is not intrinsically more accurate. (Perhaps Barry Schlesinger can comment on this - he knows this aspect much better than I) >>>Also the notion that increased ozone depletion is entirely due to >>>synthetic organochlorides must be in doubt, since the "ozone hole" has >>>recently reduced in intensity, whilst chlorine levels have continued to >>>increase. Both Cicerone and Rowlands agreed that PSCs are both critical >> >> No, except for a temporary _increase_ around 1993, probably due to >> Pinatubo aerosols extending the range of the heterogeneous chemistry, >> the ozone hole has maintained a rather constant size and depth since >> since 1989. ^^^^^^ > >You have conveniently missed the 1988 observation which shows that >PSCs are critical (which is my point). In 1988 the hole had not fully formed. (And even so, the 1988 hole is remarkable by pre-1985 standards.) Your claim was that the "ozone hole has recently reduced in intensity." It has not (aside from the post-Pinatubo recovery.) >> As discussed in the FAQ, this is expected since in >> the region where the heterogenous chemistry operates (lower half >> of the stratosphere, nearly _all_ of the ozone is destroyed when >> the hole forms.) Further incremental increases in stratospheric Cl >> won't influence the size or depth much, although they may increase >> the duration of the hole (with more reservoir Cl, the threshold for >> massive ozone destruction can be reached earlier in August.) > >Correct me if I'm wrong, Robert, but aren't you saying here that polar >stratospheric ozone depletion has basically peaked, and will not >increase appreciably no matter how much CFC is placed in the >atmosphere. Plateau'd, rather than peaked. _Incremental_ further increases in Cl will have little effect. _Large_ increases, that could allow rapid depletion to occur in other altitude or latitude ranges, is another story altogether. > If this is what you are saying, then if ozone depletion >does not cause biological harm (more on this later), then the >Montreal Protocol is pointless*, and the "ozone hole" is a storm in a >teacup. Consider the Arctic. Consider middle latitudes. The antarctic is simply the place where the stratosphere's 'buffer' is weakest. 2.5 ppbv stratospheric chlorine produced ~50% depletion over antarctica. 3.5 ppbv stratospheric chlorine has produced incipient ozone hole phenomena in the arctic. And on top of this the stratosphere is cooling and is likely to continue doing so for many decades Do you know what the third coldest place in the stratosphere is? No, not middle latitudes - it's the _tropical_ stratosphere. As Prather et al. showed back in the pre-ozone hole days ( _Nature_ _312_, 227, 1984) ozone depletion chemistry has a natural threshold built into it: the effect of incremental increases in stratospheric chlorine increases dramatically when stratospheric Cl begins to exceed stratospheric NOx. On the basis of gas phase chemistry alone, they estimated 15% *global* depletion by the middle of the next century. What they did not foresee was that heterogeneous chemistry would increase the ClOx/NOx ratio and lower that threshold. In the heavily deNoxified springtime antarctic stratosphere the threshold has been passed. In the arctic stratosphere we are getting close to it. Antarctic ozone depletion arises from an intensified variant of chemistry that occurs throughout the stratosphere. It is not a fundamentally different phenomenon. >* If evidence of bio harm is not forth-coming, it is possible that >developing countries can delay signing the MP, and thereby continue to >use CFCs indefinitely. They've already signed. And the fact that tropospheric halocarbons are already beginning to decrease makes this a moot point. >> Mid-latitude ozone depletion is thoroughly documented. > >Let's deal with each of these seperately. > >1. Mid-latitude ozone depletion. > >Whilst I agree that measurements of ozone LOSS are well documented, >the mechanism for loss has not been proven to be DEPLETION at >mid-latitudes (except due to volcanic activity). Your references >suggest (as I do) that ozone loss is due to "transport of chemically >perturbed polar air to mid-latitudes". That is _one_ mechanism. Here is the complete sentence, from WMO 1991: "Plausible mechanisms include heterogeneous chemistry on sulfate aerosols [which convert reservoir chlorine to active chlorine - R.P.] and the transport of chemically perturbed polar air to middle latitudes." WMO 1991 presents the two mechanisms - local depletion on the aerosol layer (which is always there; volcanic eruptions enhance it, but there is a background arising from stratospheric OCS) and transport from polar regions - on the same footing. Note that "chemically perturbed" doesn't just mean ozone-poor, it may also be ClOx-rich, so it can chew up mid-latitude ozone. Since the time of that report, the balance of opinion seems to be shifting away from the "transport" mechanism and towards mid-latitude heterogenous chemistry on the sulfate aerosol layer. (See WMO 1994). >2. Net loss in ozone. > >Your references demonstrate that there is a trend in PEAK ozone loss, >but does not indicate a NET loss. Each year, in summer, ozone levels >return to seasonal normal levels. False. Mid-lat Ozone depletion is seen in _all seasons_. From the FAQ: ------------------------------------------------------------- The following table, extracted from a much more detailed one in [Herman et al.], illustrates the seasonal and regional trends in _percent per decade_ for the period 1979-1990: Latitude Jan Apr Jul Oct Example 65 N -3.0 -6.6 -3.8 -5.6 Iceland 55 N -4.6 -6.7 -3.1 -4.4 Moscow, Russia 45 N -7.0 -6.8 -2.4 -3.1 Minneapolis, USA 35 N -7.3 -4.7 -1.9 -1.6 Tokyo 25 N -4.2 -2.9 -1.0 -0.8 Miami, FL, USA 5 N -0.1 +1.0 -0.1 +1.3 Somalia 5 S +0.2 +1.0 -0.2 +1.3 New Guinea 25 S -2.1 -1.6 -1.6 -1.1 Pretoria, S. Africa 35 S -3.6 -3.2 -4.5 -2.6 Buenos Aires 45 S -4.8 -4.2 -7.7 -4.4 New Zealand 55 S -6.1 -5.6 -9.8 -9.7 Tierra del Fuego 65 S -6.0 -8.6 -13.1 -19.5 Palmer Peninsula --------------------------------------------------------------- >To suggest a trend of 3%/decade, >considering the moderation in the rate of increase in polar depletion, >is disingenuous. The fact is, the "saturation" of antarctic ozone depletion has had no observable effect on the downward trend in mid-latitude ozone. BTW, the mid-latitude trend is more like 4.5% per decade. You get 3% when you average in the tropics as well. > Also, and by your own admission in your FAQ, the >current levels are very small compared to daily, seasonal and global >variations, So what? That does not render them irrelevant. Seasonal variations in the monthly mean temperature in Boulder, Colorado amount to about 20 degree C. Daily variations are far larger - I have experienced a temperature drop of 40C in a 48 hour period. Does that mean that a 1.0 degree C change in _global, annual_ temperature is irrelevant? Well, -1.0 C gets us into the "Little Ice Age" of the 18th century. -10 C gets us into the Big Ice Age. Compare apples to apples - compare the present downward trend to natural variations on similar spatial and temporal scales, such as the solar cycle and the QBO. The fact is, the present downward trend is comparable to, indeed rather larger than, these variations. >insufficient to overcome the so-called "self-healing" mechanism False. The fact that the downward trend occurs primarily in the lower stratosphere renders "self healing" irrelevant. >(as backed up by the lack of conclusive evidence of increased UV-B), The lack of conclusive evidence of increased UV-B is primarily due to the fact that we do not have a "pre-ozone-depletion" baseline for it. >>>or that the seasonal losses cause any damage to the biosphere. >> >> What about the antarctic phytoplankton? See the Smith et al. paper, >> cited in Part IV of the FAQ. > >As Smith points out, the damage is several orders of magnitude too >small to be considered significant. Smith points out no such thing. His results are far from catastrophic. That does not render them insignificant. >>> (Claims that skin cancer in humans may be attributed to ozone depletion is >>> nonsense.) >> >> Not at all. See DeGruijl's paper in CONSEQUENCES, on the web at >> http://www.gcrio.org/CONSEQUENCES/summer95/impacts.html >> Just because the media exagerrates the effects, does not mean that >> the effects do not exist. > >"[...] Although the rate of loss has now been slowed, total ozone is >expected to continue to drop through the present decade, when the >decrease at mid latitudes in the Northern hemisphere in summer and >fall should maximize at 6 to 7%. A reduction in ozone of this amount >would correspond to a resulting 6 to 12% increase in the average >annual dose of biologically-harmful UV radiation." [DeGruijl] > >Interesting assumption on which to base a THEORETICAL analysis. And >where is the data to back up this assumption? D'oh! Why not pursue the subject and learn where the data is? Learn something about atmospheric radiative transfer and UV photobiology. These are mature subjects with an extensive literature. Nonmelanoma skin cancer, particularly squamous cell carcinoma, is one of the best understood of all cancers - the mechanism is known in detail at the molecular level. The dose-response curve is well known. The UV trends themselves aren't well known, but that situation is finally changing. >>>Methyl chloride (CH3Cl) comes mostly from natural (biological) sources, and >>>is estimated to pass from the troposphere to the stratosphere at >>> the rate of about 1 Mt/year. >> >> That estimate is at least an order of magnitude too large. _Total_ >> organic chlorine entering the stratosphere in the 1980's was >> around 300 kt/year, of which only ~20% was MeCl. This figure is >> given and cited in the FAQ, Part II, Section 4.4. > >[from your FAQ] >"During the 1980's emissions of CFC's and related >compounds contributed ~1 Mt of chlorine per year to the >atmosphere. [Prather et al.] This results in an annual flux of >0.3 >Mt/yr of chlorine into the stratosphere." > >Here you are talking about total chlorine flux, as opposed to total >flux of chlorine compounds, which is what I am talking about. It is a >little unfair of you to compare oranges to apples, don't you think, >Robert? Doesn't affect the argument. (0.20)(.300Mt/yr) = .060 Mt/yr Cl from MeCl. Multiply by (12+3+35.5)/35.5 to get .085 Mt MeCl/yr. Which is still more than an order of magnitude off from your claimed 1 Mt/yr, as I asserted. >>>This also implies that there is no downward drift either. >> >> It most emphatically does not. *There is a sink in the troposphere.* > >Well, hang on, you can't have it both ways. If HCl is passing through >the tropopause to this sink, why isn't it measured at the tropopause? Because it's being drained throughout the tropopause region. What does the solution to the diffusion equation with an absorbing boundary condition on one wall look like? A smooth increase away from the wall. >> In fact, the comparison between HF and HCl mixing ratios, recently >> carried out on a global scale by the HALOE project, demonstrates >> clearly that stratospheric HCl is primarily anthropogenic. >> See http://haloedata.larc.nasa.gov/home.html, and read the >> published papers. > >And I do not deny this, although to say "primarily" without further >quantification is little misleading. But that is not the thrust of my >argument. I am merely pointing out that there was lots of >stratospheric Cl prior to CFCs ie all the ingredients of ozone >depletion were there prior to CFCs. You claimed that the natural background is larger than the anthropogenic component. That claim is false. >>>2. Ozone depletion causes no biological damage. >>> >>>Ozone depletion at the poles results in insignificant UV increase, >>>because the sun is so low on the horizon. >> >> The FAQ documents _measured_ springtime UV in Antarctica that >> exceeded _midsummer_ UV in San Diego, Ca. Why was that left out? > >As I have already pointed out, mid-latitude UV-B measurements are not >relatively high, particularly when the measurements are made under a >photochemical haze. The latitude of San Diego is about the same as Casablanca, Morocco; Jerusalem, Israel; or Lahore, India. These are not exactly low-UVB environs. As for "photochemical haze", San Diego is not Los Angeles. You claimed that "ozone depletion at the poles results in insignificant UV increase." I submit that springtime UV on the Antarctic Peninsula that exceeds summertime UV in San Diego is hardly "insignificant." > >You also know that the hole centres over the Antarctic continent. Not always - it is often off-center. >> The Antarctic Ocean is hardly "devoid of life larger than microbes." > >Lower depletion levels do (I admit) extend over Antarctic Ocean >waters, but the depletion levels are much lower than the maximum >levels at the centre. No. Look at the TOMS maps. Severe depletion can extend far over the ocean. The UV-B measurements referred to above were made at Palmer Station, far out on the Antarctic Peninsula which extends far into the ocean from the main part of the continent. >>>At mid-latitudes increase in UV due to ozone depletion is very low >>>compared to daily, seasonal and global variations. This is due to an >>>absence of PSCs (at mid-latitudes) and so ozone depletion only takes >>>place there in the presence of sulphate aerosols from volcanic activity >>>(which is natural). >> >> The chlorine - which is what actually destroys the ozone - is >> predominantly anthropogenic. And, there is a background aerosol >> layer in the absence of volcanic eruptions. And, ozone depletion >> also takes place through purely gas-phase mechanisms - this was >> the original Molina-Rowland process. > >Proof!? 1.) Observation of high ClO concentrations in the upper stratosphere, first seen in 1977. Direct evidence that the Rowland Molina mechanism is operating up there. (The only way to get ClO in the upper strat. is from Cl attack on O3.) 2. Observed _upper_ stratospheric ozone depletion at all latitudes. 5% per decade at the equator, 10% per decade at high mid latitudes. See WMO 1994, p. 1.28. (It's an old result, actually; it just hasn't gotten much attention because of the more dramatic depletion in lower stratospheric ozone; most of the ozone layer is in the lower stratosphere.) > Significance to biological harm!? Smaller in magnitude, and a much longer time lag before the effects become important, but nevertheless significant in the long term. (Since ozone is produced in the upper stratosphere and mesosphere, depletion of upper stratosphere ozone will eventually lead to losses throughout the stratosphere.) >>>Rowland relies on the lack of observation by Dobson (which IMO is >>>anecdotal). I have not posed the question to Molina. >> >> "Anecdotal"?!! The 1956-58 results are in the published literature >> (reference: the Applied Optics paper cited in the FAQ, and an earlier > >[...etc...] > >I know. But there was, and still is, conjecture over whether what was >published, and what was observed, are the same thing. Conjecture by whom? All I've seen is the reminiscences of an old atmospheric dynamicist regarding what Dobson told him some 35 years ago. And don't forget to read the Newman paper, which reproduces antarctic ozone measurements from several locations during IGY. > OK, I admit >that formal publication is the only thing scientists can go on, but >the seeds of doubt are there. >> The calculations are wrong in a number of respects. For one thing, >> they were based upon a fundamentally incorrrect picture of atmospheric >> dynamics (strat/trop exchange in particular.) > >1. As I have already said, I appreciate you correcting my >understanding re strat/trop exchange. However, since my calcs are >based on direct measurement of HCl, the results do not rely on this >issue. They do indeed rely upon it. You compare the HCl annual increase to the annual halocarbon influx. This only makes sense if these are the only places for the Cl to go. By omitting the HCl efflux from the stratosphere _and_ omitting photolysis of CFCs already in the stratosphere you are leaving out a huge portion of the balance. >2. By comparing DIRECT measurement of increased HCl (which of course >includes any sink for HCl which may exist) with known CFC flux, I calc >the natural vs anthropogenic ratio in terms of flux. This leads to a >figure for the natural burden. You act as if the only CFCs that can dissociate in year n, are those that cross the tropopause in year n. This is not a sensible procedure. >> are way off (for example, an estimate of ~1 Mt of methyl chloride >> per year entering the stratosphere, which is at least an order of >> magnitude too large.) > >3. As I have already pointed out, the calcs are a BOTE and therefore >very rough, but I do not concede that they are "way off". You appear >to have arrived at your conclusion by failing to recognise the >difference between total CH3Cl flux and total Cl flux. There is a >difference. You are still more than an order of magnitude off. >> For a fourth, additional Cl reservoirs such >> as ClONO2 are left out. The partitioning of Cl between HCl and ClONO2 >> varies with latitude and season. > >I understand the importance of ClONO2, but could find no base >measurement data in order to include it in my calcs. Perhaps you can >point out to me how it's exclusion from my calcs affects my conclusion >re natural burden of Cl. Once again, you are leaving a major part of the Cl out of the balance. Suppose, for example, that 99% of the halocarbon Cl went into ClONO2. Clearly, the increase in HCl would _not_ correspond to the rate at which halocarbons were producing Cl in that case! I repeat, that such mass-balance analyses _have_ been done and are in the literature. The Rinsland et al. paper has references to one. And any attempt to estimate the stratospheric chlorine balance _has_ to deal with the HALOE data. ------ Robert Newsgroups: sci.environment,talk.environment,aus.politics From: B.Hamilton@irl.cri.nz (Bruce Hamilton) Subject: Re: Ozone hole=storm in a teacup Date: Fri, 13 Dec 1996 19:38:08 GMT eggsoft@sydney.dialix.oz.au (Greig Ebeling) wrote: >"Sam McClintock" <scmcclintock@ipass.net> wrote: >>Greig Ebeling <eggsoft@sydney.dialix.oz.au> wrote: >>> If ozone depletion does not cause biological harm, then why do we need >>> to go to all this effort to make the hole disappear? >>How silly of me. I am so terribly sorry, but I seemed to have overlooked >>that criteria. Please explain to us how losing the ozone layer will not do >>any harm. It would be an important point. >Try this quick quiz. Oh goody! A quiz, but no prizes for correct answers? How miserable.... Anyway, onwards.... >1. Who says that we are ever going to "lose" the ozone layer? >(Statistical evidence of a NET loss in ozone required, along with >proof of an on-going downward trend). I would prefer to leave some of this to people with access to the appropriate journals and reports, but in "Estimates of ozone depletion and skin cancer incidence to examine the Vienna Convention achievements". H.Slaper et al ( Nature v.384 p.256-258 21 November 1996 ) start their abstract with " Depletion of the ozone layer has been observed on a global scale ", and cite the 1995 WMO Report 37 "Scientific Assessment of Ozone Depletion:1994 Global Ozone Research and Monitoring Project as the reference. The proof of a on-going global downward trend will presumably also be obtained from the same reference by comparisation with earlier assesments from the from the same project.. But I don't have access to those reports, so.... A more accessible plot of the % Mean Global Ozone Depletion relative to 1980, averaged annually and over the latitutes 65S to 65N, as measured by the TOMS/SBUV satellite is available in "The ozone layer, the road not taken" M.Prather, P.Midgley, F.S.Rowland, R.Stolarski. ( Nature v.381 p.551-554) From eyeballing the plot, Year Total Ozone 1979 0.8 1980 0.0 1981 0.1 1982 -0.2 1983 -1.8 1984 -1.7 1985 -3.3 1986 -2.8 1987 -2.5 1988 -2.4 1989 -2.3 1990 -1.0 1991 -2.2 1992 -1.4 1993 -3.4 1994 -5.5 Now please let me know which graphing package shows that as no change in ozone, or an increase. Such software whould be a great help to me when I have inconvenient data. Down here, a nice Figure in " Ozone depletion and UV radiation: A health risk for New Zealanders?" R.McKenzie ( The New Zealand Public Health Report. October 1996 p75-77 ) plots the Annual Mean Ozone measured over southern New Zealand for the years 1971-1995. In the Results section, the author notes; "Ozone declined by approximately 5-7% in New Zealand between the mid 1970s and the 1990s (Figure 1). Based on this rate of ozone depletion, erythemal UV has been calculated to have increased by 6-9% in NZ since the 1970s. Since the early 1990s, ozone levels in NZ have stabilised, but globally they have continued to decline. Further ozone depletion over NZ may be expected as the concentrations of ozone-depleting chemicals continue to increase." Direct measurements of UVR ( ultraviolet radiation ), from the R-B meter in Invercargill for part of the period, also indicate that there has been an increase in UVR... Spectrally-resolved measurements have clearly shown the expected inverse correlation between ozone and UVR [ the 1994 WMO report above is indicated as the source of that data ] " " NZ experiences relatively intense erythemal UV during the summer months, whose levels can approach those at the equator, and can exceed those at comparable northern latitudes by 40% [GRL v22 p1889-92] This difference between NZ and comparable northern latitudes is due to: (1) the sun-earth separtion being minimal in December/January; (2) hemispheric differences in ozone which result in less ozone in the summer hemisphere summer; and (3) the generally more polluted skies in the northern hemisphere providing further shielding. UV shows a strong diurnal variation, peaking when the sun is highest in the sky - about 130pm NZ DST. UV also shows a strong seasonal variation ( figure 2 ). Clouds influence UVR. However, over the course of a day , clounds that block the sunlight have a surprisingly small effect, with the total UVR rarely being reduced by more than 50%. Over a full year, the presence of clouds reduces the clear skies UVR by approximately 25%. Clouds that do not actually block the sun can be brighter than the sky, resulting in UV increases that sometimes exceed 20% [ R.L.McKenzie, G.E.Bodeker et al. Weather & Climate, in press ]. UVR is more intense in the north of NZ where solar elevations are higher and where there is less ozone, despite the fact that the ozone depletion is more rapid in the south. In the summer there is about 10% more erthymal UV in the north, and in the winter over twice as much. Averaged over a year, the north receives 25% more than the south". [ same "in press" reference, but similar NZ data using actinic UV radiometers from 1988-1995 is available in "Erythemal Ultraviolet Insolation in New Zealand at solar Zenith Angles of 30 and 45 degrees. K.G.Ryan et al. Photochemistry and Photobiology v63 p628-632 (1996) ] - which also shows that an average monthly rate of increase in UVR of 9.1% (SZA=30 degrees) and 8.3% (SZA = 45 degrees ) going from spring to autumn. An earlier paper ( P&P v57 p513-517 ) by the same group also shows higher UV radiant energies at lower latitudes for the same time of the year. >2. How do you know that ozone depletion causes harm? (references >showing a correlation between ozone loss and significant statistical >evidence of harm are compulsory in answering this question) In the same Public Health journal issue, and paired with the above article, is "Recent trends in melanoma in New Zealand" J.L.Bulliard, B.Cox ( The New Zealand Public Health Report. October 1996 p73-75 ) [ I'm not going to list all the references in detail, and "melanoma" will refer to CMM ] " Cutaneous malignant melanoma is of concern because of its frequency, the rapid increases observed in incidence and mortality over the last few decades in most populations of Eurpeoan descent [1], the relatively young age distribution of patients, and the poor survival among those with thicker lesions. Incidence rates in the non-Maori population of NZ have continuously been among the highest registered worldwide, and are only exceeded by rates in some Australian states and among white Hawaiian men [2]. NZ males and females have the highest melanoma mortatily rates in the world [3]. .. About 9 out of 10 melanomas occurring among populations of European descent in NZ and Australia are attributable to sun exposure [5], which makes melanoma potentially one of the preventable cancers." The article has some nice plots of the age-standardised incidence and mortality rate data from 1968-1993 for the non-Maori population if NZ. and notes that overall mean annual increase of incidence over the period was approximately 5% for males and 3% for females, going from around 8/100,000(1968) to 25/100,000(1993). The mortality rates have climbed from about 2.5/100,000 to 5.5(men) and 3.5(women) - with the early detection and spot check programmes starting in the mid 1980s believed to have been responsible for the mortality not tracking the incidence. Melanoma was the leading cancer for males under 50 years, and females under 35 years. They also note that there has been little change during the 1930-80 period to the histopathological diagnosis of melanoma, and that the large increases in age standardised incidence rates are real. So how does this relate to UV?. The article provides a table of age-standardised incidence rates by regional health authority and gender from 1968-93. RHA Mean Latitude Males Females North 36 degrees S 20.7 25.0 Midland 38 degrees S 19.2 24.2 Central 41 degrees S 16.3 20.3 South 44 degrees S 13.8 18.6 They then note, "Overall, incidence rates of Melanoma in NZ are higher than expected on the basis of the country's latitude, being about 50% higher than in Australian states of similar latitude [2]. The north-south orientation of NZ ( extending from 34S to 47S ) results in different levels in UV from the northen to southern part of the country ( see accompanying article [10]), producing a large variation in incidence rates within NZ [above table ]. When measured by the mean % change per degree of latitute, the differences with latitude were found to be greater for males than females, and for incidence compared to mortality [11]" Both papers extensively discuss confounding factors like lifestyle choices and host factors that affect exposure and susceptibility, as well as the difficulty of recalling historical exposures decades later. So, NZ has unusually high UV levels for its latitude, and the UV levels are inversely correlated with the ozone levels. NZ also has unusually high incidence of, and mortality from, cutaneous malignant melanoma - a cancer that is linked to previous episodes of sunburn in sun-sensitive people ( Controversies in the Role of Sunlight in the Pathogenesis of Cutaneous Melanoma - P&P v63 p406-409, or Photobiology of Photocarcinogenesis on p372-375 of the same journal ). The NZ population most at risk arrived from northern latitudes where UV levels were much lower. Undoubtably you can choose to dream up possible confounding factors to explain the higher UV = higher CMM in sensitive populations, such as the issues of tanning and pigmentation, but the Maori and Pacific Island communities in NZ migrated from a higher UV environment to NZ, enjoy similar lifestyle choices to the Europeans, and yet melanoma is much rarer in their populations. The European populations have also settled elsewhere in the world during the same period, but it is the areas with abnormally high UVR without extreme heat ( like NZ, Hawaii - where people can work/play all day in the sun without apparent discomfort ( but damage is occuring in sensitive people ) that have elevated rates of skin cancer. I suppose I could repeat the above exercise with non-melanoma skin cancer, where a recent estimate [ UNEP, Environmental Effects of Ozone Depletion. Ambio v24 p137-197 ] has estimated that for each 1% depletion of ozone, the associated UVR increases will result in a 2% increase in non-melanoma skin cancer - if all other factors remain the same. UVR has also been implicated skin ageing and cataract formation, but as I'm already convinced, I don't intend to waste time finding all the data, but I'm sure the WMO, UNEP, and Photochemistry and Photobiology journals will have plenty if you want the evidence. For those poor souls who strayed this far, as a present, here is a chart from the Public Health journal that gives the relationship between UV Index, Burn Time, and Relative Risk. The approximate conversion is Burn Time (minutes) = 144/UV Index. The UV index is the standard International scale. UV Index Burn Time Relative Risk (minutes0 0 ( dark ) - no danger 1 144 minimal 2 72 " 3 48 low 4 36 " 5 29 moderate 6 24 " 7 21 high 8 18 " 9 16 " 10 14 very high 11 13 " 12 12 extreme 13 11 " 14 10 " The highest NZ summer UV Index exceeds 12. Bruce Hamilton From: rparson@spot.Colorado.EDU (Robert Parson) Newsgroups: sci.environment,talk.environment,aus.politics Subject: Re: Ozone hole=storm in a teacup Date: 15 Dec 1996 00:59:03 GMT In article <58su7v$ari$2@coffee.DIALix.COM>, Greig Ebeling <eggsoft@sydney.dialix.oz.au> wrote: >rparson@spot.Colorado.EDU (Robert Parson) wrote: >>_Incremental_ further increases in Cl will have little effect. > >Interesting. > >>_Large_ increases, that could allow rapid >> depletion to occur in other altitude or latitude ranges, is another >> story altogether. > >Another story indeed. Whether ozone depletion occurs significantly in >the absence of PSCs (ie at other latitudes and altitudes), remains >highly questionable. A reasonable amount of observational data >demonstrating that this actually can/does occur would be necessary, >before a confident prediction can be made. Stratospheric cooling can stabilize the vortex and increase the latitude range over which PSCs are abundant. This is discussed in the Schoeberl and Hartmann paper cited in the FAQ. >[snip] > >> Consider the Arctic. Consider middle latitudes. The antarctic is >> simply the place where the stratosphere's 'buffer' is weakest. > >I'm not sure what you mean by this, Robert. My understanding is that >the antarctic is unique because stratospheric temperatures are more >persistently low, resulting in more PSCs, hence more ClO is available. And if you have more total inorganic Cl, you need fewer PSCs to reach the threshold of nonlinear ozone destruction. Indeed this is probably the reason why the Antarctic Ozone Hole seems to be growing in _duration_ - opening earlier in August. With enough inorganic Cl you won't need PSCs at all - that is the point of the Prather et al. paper, which was written before anybody knew about the effects of PSCs. PSCs are basically an amplifier. >> 2.5 ppbv stratospheric chlorine produced ~50% depletion over >> antarctica. 3.5 ppbv stratospheric chlorine has produced incipient >> ozone hole phenomena in the arctic. > >PSCs also occur to a lesser extent over the arctic, but they are less >persistent than in the south, so polar ozone depletion is much less >than in the south. To suggest that it is incipient wrt Cl ppvs is not >consistent with the observation of "plateau'ing" in the south, which >is due (put simply) to exhaustion of the ClO generation process due to >PSCs. No, no, no. The "plateau" is due to exhaution of the _ozone_ in the vortex core, not to exhaustion of the ClO generation process. > The observation indicates that increased Cl concentration will >not increase polar ozone depletion, since PSC supply is the limiting >factor. No, With fewer PSCs, you need more total Cl to reach the threshold of nonlinear ozone depletion. >> And on top of this the stratosphere >> is cooling and is likely to continue doing so for many decades > >Yes indeed, there appears to be a cooling trend, which I understand is >due partly to increased CO2, but mostly due to ozone depletion itself. >With the current "plateau'ing" of ozone depletion, we could perhaps >predict a corresponding plateau wrt to stratospheric temperature. There is no sign of a "plateau" in ozone depletion outside the antarctic. And the CO2 cooling will continue to increase in importance. (This is largely independent of the extent to which greenhouse _warming_ takes place at the surface - greenhouse stratospheric cooling is a much more robust result.) >> Do you know what the third coldest place in the stratosphere is? >> No, not middle latitudes - it's the _tropical_ stratosphere. > >Unless you are prepared to predict the appearance of PSCs, or a long >polar night, at the tropics, then I fail to see the relevance of this >observation to ozone depletion. There have, in fact, been a few reports of PSCs in the tropics. >[snip] > >[snip] > >> The following table, extracted from a much more detailed one in >>[Herman et al.], illustrates the seasonal and regional trends in >>_percent per decade_ for the period 1979-1990: > >> Latitude Jan Apr Jul Oct Example > >> 65 N -3.0 -6.6 -3.8 -5.6 Iceland >> 55 N -4.6 -6.7 -3.1 -4.4 Moscow, Russia >> 45 N -7.0 -6.8 -2.4 -3.1 Minneapolis, USA >> 35 N -7.3 -4.7 -1.9 -1.6 Tokyo >> 25 N -4.2 -2.9 -1.0 -0.8 Miami, FL, USA >> 5 N -0.1 +1.0 -0.1 +1.3 Somalia >> >> 5 S +0.2 +1.0 -0.2 +1.3 New Guinea >> 25 S -2.1 -1.6 -1.6 -1.1 Pretoria, S. Africa >> 35 S -3.6 -3.2 -4.5 -2.6 Buenos Aires >> 45 S -4.8 -4.2 -7.7 -4.4 New Zealand >> 55 S -6.1 -5.6 -9.8 -9.7 Tierra del Fuego >> 65 S -6.0 -8.6 -13.1 -19.5 Palmer Peninsula >>--------------------------------------------------------------- > >Bearing in mind that this table does not actually show seasonal >variations, but the variations for each season from year to year. It >also does not show daily and global variations which are also very >large by comparison with the figures. Once again, the fact that the seasonal variations are larger than the long-term trend does not make the latter unimportant. >Since I have not seen the original table in Hermann et al., I am left >to wonder how these figures were extracted. Are they a direct >comparison between 1979 and 1990, or perhaps between the peak values >during that period? Since I presume you made the extraction, Robert, >perhaps you could satisify my curiosity. The complete table contains all months and more latitudes. I just didn't feel like typing it all in. This is _not_ a spot comparison. The trends are obtained from a statistical analysis of the entire time series in each latitude band. >> BTW, the mid-latitude trend is more like 4.5% per decade. You get >> 3% when you average in the tropics as well. > >Why is it not appropriate to include the tropics? Surely the >mid-latitude process (action on the sulphate aerosol layer and gas >phase mechanism), should occur equally at the tropics. I note that >the table extracted from Hermann et al. shows that this does not >occur. Why is that? For a variety of reasons, some having to do with the temperature dependence of the reaction rates (some get faster at higher temps, some slower) some having to do with the height of the tropopause, (the whole stratosphere is at higher altitudes in the tropics, and this affects the density of the aerosol layer and other things) some having to do with transport (in middle latitudes, chemistry and transport are strongly coupled; ozone being destroyed here shows up as ozone loss somewhere else). I don't know if a simple rationale is possible; calculations based on known chemistry and dynamics do show local depletion increasing away from the tropics. (In fact this even shows up in the calculations in WMO 1985, which use only gas-phase chemistry.) >>> Also, and by your own admission in your FAQ, the >>>current levels are very small compared to daily, seasonal and global >>>variations, > >> So what? That does not render them irrelevant. > >Well, no, not irrelevant. Just insignificant wrt terrestrial UV-B >levels and natural biological resistance to UV damage. And at the end >of the day, that is what is important. Not so. A small change in the mean of a fluctuating quantity results in a _large_ change in the probability of extreme events. And at the end of the day, it is the extreme events that count. You aren't likely to get DNA damage on an average day, you get in on a very high UV day. The calculated increases in nonmelanoma skin cancer, mentioned elsewhere in this thread, are based upon precisely these supposedly "insignificant" increases in UV. >> The lack of conclusive evidence of increased UV-B is primarily due >> to the fact that we do not have a "pre-ozone-depletion" baseline for it. > >But we do have a sufficient "pre-ozone-depletion" baseline for >prediction of trends in ozone loss? Of course. We have the world-wide network of Dobson stations going back to the 1950's. We have single-station measurements going back to the 20's and '30s. For total UV we have nothing remotely comparable. The data simply aren't there. > You can't have it both ways. We can, and do. >>>Interesting assumption on which to base a THEORETICAL analysis. And >>>where is the data to back up this assumption? D'oh! > >> Why not pursue the subject and learn where the data is? Learn >> something about atmospheric radiative transfer and UV photobiology. > >I have become quite used to individuals accusing me of ignorance, as a >cover for their own lack of ability to engage the questions I raise. >I had previously thought, Robert, that you are above that method of >obfuscation. I am not trying to obfuscate. I am suggesting that you should spend some time investigating the literature before passing judgement on a paper. You did _not_ do this when you tried to model the Cl balance, for example, and as a result got terribly confused. Seriously, you need to start doing your homework _first_, instead of continually tossing out assertions and challenging others to refute them, and then coming back with _more_ assertions. >DeGruijl's paper predicts a correlation between ozone loss and cancer. >If the correlation was between UV-B exposure and cancer, I would >accept it. But since the jury is out when it comes to correlating >ozone loss and increase UV-B exposure, DeGruijl has made an >inappropriate leap of faith in his conclusion. >> These are mature subjects with an extensive literature. Nonmelanoma >> skin cancer, particularly squamous cell carcinoma, is one of the >> best understood of all cancers - the mechanism is known in detail >> at the molecular level. The dose-response curve is well known. >> The UV trends themselves aren't well known, but that situation >> is finally changing. > >I don't doubt any of this Robert. But it's off the point. The issue >is this: is there a correlation between ozone depletion and >significant increases in exposure to UV-B, and if/when this occurs is >the harm consistent with our efforts to prevent it. If a correlation >or cost/benefit can't be shown, then all the knowledge in the world >about UV/cancer and CFC/ozone loss yields nothing of any relevance (ie >its a storm in a teacup). There _is_ evidence of a correlation. At this time it is indirect, because of the lack of surface UV measurements - in particular, the absence of a pre-ozone-depletion base line. Nevertheless there is a good deal of indirect evidence, based upon measurements of ozone-UV correlations at particular locations. I have cited some of these in the FAQ. Total UV measurements are inherently more difficult than ozone measurements (after all, what the Dobson spectrophotometer actually measures is relative UV-B intensities, and absolute measurements are always more difficult than relative ones, a fortiori when the latter must include scattered as well as direct solar radiation.) Combining this with the absence of a pre-ozone-depletion baseline, and the very limited amount of data available prior to the past couple of years,I don't think it particularly surprising that the present level of mid-latitude ozone depletion has not _yet_ been identified as a trend in measured surface UV-B. It means that we need to improve the quality and quantity of the measurements, while at the same time investigating the physics to make sure that we have identified all confounding factors. >> As for "photochemical haze", San Diego is not Los Angeles. > >Show me a North American city unaffected by car exhaust pollution. I stand by my statement: measured springtime UV on the Antarctic peninsula exceeded measured UV in San Diego in all seasons, including midsummer. >> You claimed that "ozone depletion at the poles results in insignificant >> UV increase." I submit that springtime UV on the Antarctic Peninsula >> that exceeds summertime UV in San Diego is hardly "insignificant." > >I did not say that UV increase AT the poles was insignificant, only >that polar ozone depletion resulted in insignificant increases in UV >exposure (in populated areas ie mid latitudes). Nope. What you said was: >>>Ozone depletion at the poles results in insignificant UV increase, >>>because the sun is so low on the horizon. To me that implies that you were talking about UV at the poles. >PS I have snipped the issues, history of photospectrometric >measurement, and natural stratospheric chlorine budget. For brevity >and the sake of others, I must concede, bowing to Robert Parsons >greater knowledge on these subjects. They are also not very important >to my overall thesis regarding the state of the tea-leaves in my >morning cuppa. I commend Greig Ebeling's willingness to publicly retract his assertions when presented with contrary evidence, although, as noted above, I am frustrated by always having to be the one to provide the evidence, even when it's already in the damn FAQ. I have never been interested in convincing anyone to adopt any particular position on matters of policy. My observation has been that the great majority of people who actually take the trouble to investigate the science in depth have ended up supporting a relatively swift CFC phaseout. This includes people of all sorts of political persuasions and indeed of a variety of position on environmental issues in general - Paul Dietz, Steinn Sigurdsson, and the late Carl J. Lydick are not usually regarded as environmental extremists :-). ------ Robert From: Jonathan Shanklin <j.shanklin@bas.ac.uk> Newsgroups: sci.environment Subject: Re: Ozone Depletion is a FRAUD !!! Date: Wed, 09 Jul 1997 10:28:34 +0100 This is a multi-part message in MIME format. --------------446B794B15FB -- Jon Shanklin j.shanklin@bas.ac.uk British Antarctic Survey, Cambridge, England http://www.nbs.ac.uk/public/icd/jds/ozone/ --------------446B794B15FB There is an oft quoted statement that the Antarctic ozone hole was discovered in 1956 and therefore it can't be caused by CFCs. This remark originates from a paper by Professor G M B Dobson, the scientist who designed the ozone spectrophotometer which has been the standard for ozone measurements since the 1930s. The big advantage in standardising on one make of instrument is that we can be certain that changes in ozone amount that are measured, are changes in the atmosphere rather than changes due to observational technique. The following is taken from Dobson's paper in Applied Optics, March 1968, Vol 7, No3. 'One of the more interesting results on atmospheric ozone which came out of the IGY (International Geophysical Year) was the discovery of the peculiar annual variation of ozone at Halley Bay (76 south, 26 west). The annual variation of ozone at Spitzbergen was fairly well known at that time, so, assuming a six months difference, we knew what to expect. However, when the monthly telegrams from Halley Bay began to arrive and were plotted alongside the Spitzbergen curve, the values for September and October 1956 were about 150 units lower than was expected. We naturally thought that Evans has made some large mistake or that, in spite of checking just before leaving England, the instrument had developed some fault. In November the ozone values suddenly jumped up to those expected from the Spitzbergen results. It was not until a year later, when the same type of annual variation was repeated, that we realized that the early results were indeed correct and that Halley Bay showed a most interesting difference from other parts of the world. It was clear that the winter vortex over the South Pole was maintained late into the spring and that this kept the ozone values low. When it suddenly broke up in November both the ozone values and the stratosphere temperatures suddenly rose.' This table shows the difference between what Dobson expected from Spitzbergen, the normal values observed at Halley between 1956 and 1975 and the values presently observed. Mean October ozone values have fallen by around 3% per year since 1976, while the amount of chlorine has risen by 3% per year. Spitz Feb Mar Apr May Jun Jul Aug Sep Oct 1956 440 470 450 400 350 320 300 280 280 Halley Aug Sep Oct Nov Dec Jan Feb Mar Apr 1956 300 300 300 330 350 320 300 280 280 1996 172 155 149 181 260 278 265 245 242 The Antarctic ozone hole is the depletion in the spring over and above that caused by the different atmospheric circulations in the two hemispheres. Signs can be seen in data from 1976 when you know what to look for, but suspicion didn't really arise until the end of the decade and the paper announcing the discovery of ozone loss in the Antarctic was not published until 1985. When American satellite data was reanalysed it became apparent that it was a phenomena that covered the whole of the Antarctic and it was given the name ozone hole. The latest data also show ozone depletion during the summer and autumn months, in addition to the spring- time 'hole'. --------------446B794B15FB-- |
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