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Appendix C Glossary Special Terms Albedo-Reflectivity of clouds, land, ocean, ice, or snow surfaces to incident solar radiation. Antarctic ozone hole A substantial reduction below the naturally occurring concentration of ozone over Antarctica. Catalytic cycle Refers, in these proceedings, to a cycle of chemical reactions, involving several chemical compounds, that results in the destruction of ozone molecules by ionized chlorine atoms. Climate mode!-A numerical simulation of the climate system. CTi- mate models are of two basic types: (1) static, in which atmo- spheric motions are neglected or are represented with a simple parameterization scheme such as diffusion, and (2) dynamic, in which atmospheric motions are explicitly represented with equa- tions. The latter category includes general circulation models (GCMs). Dobson unit A measure of total column atmospheric ozone. If brought to 1 atmosphere (1013.2 mb) of atmospheric pressure, 100 DU of pure ozone would measure 1 mm thick. Normal total column atmospheric ozone averages about 300 DU. 113

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114 APPENDIX End ejects In the analysis of a time-series of observations, refers to the increased uncertainty in estimating trends near the beginning and end of a series record. Feedback-In climate studies, the amplification (positive feedback) or dampening (negative feedback) of climate change by climatic processes that are a consequence of the change. Greenhouse gases Trace gases in the atmosphere that are strongly absorbent in parts of the infrared wavelength spectrum. These include carbon dioxide, methane, nitrous oxide, and some of the chIorofluorocarbons. Heterogeneous chemistry-A category of chemical reactions that in- volve both gaseous and liquid ingredients. Ice core data Paleoclimatic temperature data deduced from chem- ical composition, and its variations with time, of ice samples obtained by vertical drilling in glaciers. Lidar-Light detection and ranging system. An instrument that uses infrared or visible light in the form of a laser beam to measure wind speed and direction from the movement of wind-borne aerosols. Mean life Time required for concentrations to diminish to 1/e of the original value. Microwave sounder unit A satellite-based remote sensor capable of measuring temperature in the lower stratosphere under certain conditions. Mode} physics In climate models, the representation of physical processes, especially atmospheric radiative balance and heat ex- change processes between, for example, atmosphere and ocean and atmosphere and ice. Montreal Protocol-An international agreement to limit and eventu- ally reduce the amount of chIorofluorocarbons injected into the atmosphere. Terms of the agreement reached in Montreal on September 16, 1987, are summarized in Chapter 3. Ozone self-healing-Refers to the hypothesis that a reduction of ozone in the higher stratosphere would allow more ultraviolet radiation to penetrate to the lower stratosphere and create more ozone there, thus limiting total column ozone depletion. Ozonesondes ---(a) Instruments that measure the vertical profile of ozone concentration in the atmosphere; (b) vertical profiles of atmospheric ozone concentration. Pa~ameterization In numerical models of the climate system, the representation of a physical process by statistical or empirical

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APPENDIX a 115 relationships rather than by equations that explicitly describe the physical process. Polar vortex In the stratosphere, a strong belt of winds that encir- cles the South Pole at mean latitudes of approximately 60S to 70S. A weaker and considerably more variable belt of strato- spheric winds also encircles the North Pole at high latitudes during the colder months of the year. Radiosondc- Instrument system carried aloft into the atmosphere by balloon; it measures atmospheric pressure, temperature, and humidity, and relays this information to a receiver at the launch site. Solar maximum The time of maximum sunspot activity during the solar cycle of approximately 11 years. The last solar maximum occurred in 197~1980. Solar minimum The time of minimum sunspot activity during the solar cycle. The last solar minimum occurred in 198~1986. Stratosphere Portion of the atmosphere between the tropopause (at 8- to lam elevation, depending on latitude and season) and the stratopause (approximately 50 km). Umkehr network-A network of ground-based Dobson instruments that measure ozone concentrations in atmospheric layers. Abbreviation AER CFC Atmospheric and Environmental Research, Inc. ChIorofluorocarbon. The primary CFCs affecting ozone concentrations are CFC-ll (trichIorofluoromethane) and CFC-12 (dichiorodifluoromethane). CFM ChIorofluoromethane-type compound. See CFC. CGC Committee on Global Change. DU Dobson unit (see special terms). ECMWF European Centre for Medium-Range Weather Forecasts EOS Earth observing system. GAGE Global Atmospheric Gas Experiment. GCM General circulation mode! (see climate model). GFDL Geophysical Fluid Dynamics Laboratory, NOAA. IGBP International Geosphere-Biosphere Program. IGY International Geophysical Year. JPL Jet Propulsion Laboratory. mb Millibar (of atmospheric pressure). One mb equals 1,000 dyne/cm2 or 100 Pa.

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l 116 NASA NCAR NMC NOAA NSF PSCs QBO SBUV TOMS TOYS UV WMO APPENDIX C National Aeronautics and Space Administration. National Center for Atmospheric Research. National Meteorological Center, NOAA. National Oceanic and Atmospheric Administration. National Science Foundation. Polar stratospheric clouds. These ic~crystalline clouds have been observed in polar regions in winter and spring. Quasi-biennial oscillation. An approximately Month periodic reversal of equatorial stratospheric winds between easterly and westerly direction. SAGE Stratospheric Aerosol and Gas Experiment (SAGE T and Il). Refers to experimental remote-sensing instruments aboard satellite platforms. Solar back~catter ultraviolet (satellite instrument). Total Ozone Mapping Spectrometer. A remote sensor mounted on the NIMBUS-7 satellite that measures total column ozone. TIROS operational vertical sounder. Ultraviolet (wavelength of electromagnetic radiation). World Meteorological Organization.

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l Index A Administrative issues, 5-6 Aerosols, 28, 32, 46, 87 Airborne Antarctic Ozone Experiment, results, 64 Aircraft atmospheric measurements, 26-27, 83 chlorine monoxide, 58, 6~61 rocketsondes, 86 Albedo, 98, 100 Albritton, Daniel L., 10-18, 57 Altitudinal effects, 15, 16, 63, 70 Anderson, James G., 27, 30, 56-65 Angell, J. K., 89, 90 Antarctica, temperature trends, 90-96, 100 Antarctic ozone depletion, 19-32 Antarctic ozone hole, 10, 16, 72 analysis of, 19-32 causes, 25-32, 49-51, 59-64 Northern Hemisphere counterpart, 76-77 temperature changes due to, 91 Atmospheric and climatic models, 13, 16, 19 accuracy, 77 of circulation, 17, 101-102 117 ozone depletion, 41-43, 58-59, 68-70 stratospheric climate change, 66-78 em also Numerical analyses and models; Prediction and predictive models Atmospheric and Environmental Research, Inc., 68-69, 71 Atmospheric chemistry, 2 antarctic ozone hole, 25-30 chlorinated compounds and 11, 26, 27, 30, 34, 48-55 free radicals, 56-65; Cc also epecipc free radicals heterogeneous chemistry of ozone depletion, 48-55 hydroxyl levels, predictive models, 83 stratosphere, homogeneous gas-phase catalysis in, 56-59 64-65 ultraviolet radiation and ozone creation, 39-40 Atmospheric circulation antarctic ozone hole, 25, 28, 29, 30 gravity waves, 77, 78 models of, 17, 101-102 Northern Hemisphere, 76

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118 quasi-biennial oscillation, 4041, 46, 87 stratosphere, 12, 13, 15, 57, 70, 72, 73 troposphere, 70, 73 Atmospheric free radicals, 5~65 Atmospheric methane, 79-84 Atmospheric moisture, 54-55 heterogeneous chemistry, 48-55 ice crystals, 30, 32, 49-52, 53-55 stratospheric, 31, 4050, 67, 75, 76, 98, 101 stratospheric water vapor, 67, 73 Atmo~pAcmc Ozom 1985, 38, 67-68 Atmospheric pressure, related to temperature, 92 Atmospheric temperature, 2, 28, 57, 63, 64~5 ice crystallization and, 31, 32 measurement issues, 86-87 methane and global warming, 81 Northern Hemisphere, 89 pressure, atmospheric, and, 92 seasonal variations, 87, 90-91, 99, 100 Southern Hemisphere, 89 stratospheric cooling, 1, 12, 15, 25, 67, 68, 6071, 76, 78, 85-96, 98, 99 tropospheric warming, 1, 13, 15, 55, 68, 72-75, 76, 89, 98, 99 volcanic eruptions and dust, effects, 32, 54-55, 87, 89, 90 Cc alto Greenhouse gas effect B Balloon atmospheric measurements, 58-59 osonesondes, 22-23 radiosondes, 86, 90 Board on Atmospheric Sciences and Climate, 8 Boreal regions, methane outgassing, 83 Bromine oxides, atmospheric concentrations, 27, 29, 30, 59, 63 INDEX C Carbon dioxide, 70 and chlorine compounds, 12-13, 15, 55 measurement of, 5 stratospheric, 68, 99 tropospheric, 99, 100 Carbon monoxide, 83 Catalytic cycle, 11 , 56-59, 63 CFCs, sec Chlorine compounds Chemical Manufacturers Association, 26 Chlorine compounds, in atmosphere, 33-38 and greenhouse gas effect, 17, 66 heterogeneous chemistry of ozone depletion, 32, 48-55 mean life in atmosphere, 34, 36 Mordrcal Protocol, 1017, 19, 31, 36-37 Northern versus Southern Hemisphere levels, 33-34, 36 in ozone layer, 1, 11-17, 24, 25-26, 27-30, 36-38, 48-55 in stratosphere, 36, 48-55, 56-59, 61~4, 67, 68 Chlorine monoxide, 56-58, 59, 60-65 Chlorine nitrate, 48-54, 57, 67 Clark, William C., 4-9 Climatic models, ace Atmospheric and climatic models; Numerical analyses and models; Prediction and predictive models Climatic trends, sec Greenhouse gas effects; Paleoclimatology Clouds ice clouds in stratosphere, 67 stratospheric, 31, 49-50, 67, 75, 76, 98, 101 Committee on Global Change, 8, 9 Condensed-phase chemistry, ace Heterogeneous chemistry Convection, 101 D Dichlorodi~uoromethane, 33-35 Dickinson, Robert E., 98-102 Dobson spectrometry and spectrophotometry, 14, 38, 41, 43, 46

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INDE}f E Barth System Scicnec, A Flour View, 7 El Chichon, 89, 90 El Nina, 90 Environmental Protection Agency, 17 Equatorial zone, 90 tropopause, 73 winds, quasi-biennial oscillation, 40-41,46, 87 F Free radicals, 56-65 8CC ~80 epecipc Cc radices G Gas-phase catalysis, in stratosphere, 56-59,64-65 Geophysical Fluid Dynamics Laboratory, 70,76 Glacial processes, 80, 81 Global atmospheric change, 4-9 Global Atmospheric Gas Experiment (GAGE), 33,35 Global Ozone Research and Monitoring Project, 16 Global trends atmospheric, 4-9 ozone depletion, 10-17,33-46, 66-78 temperature, 85-96 Gravity waves, 77, 78 Greenhouse gas effect, 1-2 chlorofluorocarbons, role in, 17,66 methane and, 81-82 numerical models, predictive, 98-102 stratospheric change projections due to, 66-78 Greenland, 79 Ground-based atmospheric measurements, 14,26,64 Global Atmospheric Gas Experiment, 33,35 of ozone levels, 38-41 of temperature, 89 Umkehr network, 14,46,67 119 H Halocarbons, 1, 28-29,33-46 Halocarbons and ozone depletion, 33-47 Hansen, J., 89, Too Harriss, Robert C., 79-84 Heterogeneous chemical processes, 48-55 Heterogeneous chemistry, and ozone depletion, 32,48-55,56, 76 History, of atmospheric research efforts, 4-7 Hydrogen chloride, 48-54 Hydroxyl, 57-59,81,83 Hypochlorous acid, 53 I Ice albedo and, 100 land and sea, and greenhouse effect, 99, 100, 101 Ice core data Antarctica, 79 Greenland, 79 methane sampling, 79, 80,83 Ice crystals, atmospheric, 30,32, 49-52,53-55,61 International agreements and programs, 4-5,6 Monarch Protocol, 1 0- 17,1 g ,31, 36-37 temperature and pressure measurement calibration, 86 International Council of Scientific Unions, 6 International Geophysical Year, 4-5, 14 International Geosphere-Biosphere Program, 6-7 K Karoly, D. J., 89 L Labitzke, K., 89, 90 Land ice, 99 Latitudinal effects, 13-14, 15, 16, 63, 70,71

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120 Lebedeff, S., 89 Lidar, 27 Lower atmosphere, 8CC Troposphere M Mahlman, Jerry, D., 66-78 Manabe, S., 99, 100 Mathematical models, Cc Numerical analyses and models Measurements and measuring devices antarctic ozone hole processes, 26-30 balloon atmospheric measurements. 58-59, 86, 90 calibration problems and measurement error, 14, 41, 43, 45, 86-87 carbon dioxide, 5 chlorine compounds, 33-38, 58 free radicals, 56-65 methane, 83 ozone, 11-12,13,14-16, 2~25, - 38-46 ozonesondes, 22-23 remote sensing, 26, 79 satellites, 14, 22, 25, 43, 46, 67, 83, 86, 88 temperature instruments and data. 86-96 Cc also Aircraft atmospheric measurements; Ground-based atmospheric measurements Meehl, G. A., 100 Methane, 29, 30, 73 chlorine compounds and, 12-13, 15, 55, 56-57 dichlorodilluoromethane and trichlorolluoromethane levels, 33-35 as greenhouse gas, 66 outgassing, historical trends and temperature sensitivity, 79-83 Microwave sounding, 90 Models, sec Atmospheric and climatic models; Numerical analyses and models; Prediction and predictive models Molina, Mario J., 48-55, 56 INDEX Montreal Protocol on Substances that Deplete the Ozone Layer, 1~17 antarctic ozone hole, 1Q effectiveness, 31, 36-37 scheduling of enforcement and review, 15-16 N National Aeronautics and Space Administration, 7, 25-26, 38, 67-68 National Center for Atmospheric Research, 76 National Climate Program Office, 8 National Oceanic and Atmospheric Administration, 25-26 National Research Council, 8 National Science Foundation, 26 Nitrogen compounds, 26, 27-28 in polar vortex, 29, 30 stratospheric, 48-49, 52-54, 57, 59, 64-65, 67 tropospheric, 66-67 Northern Hemisphere chlorine compound levels in atmosphere, 33-34, 36, 63, dynamics of atmosphere, 75-76 nitrogen system stability, 65 ozone levels, 25, 38-39, 43 polar ozone hole, 7~77 temperature trends, 90, 96, 101 Numerical analyses and models, 34, 41-45, 70 general circulation models, 101-102 of greenhouse gas effect, 98-102 Numerical models, 98-102 o Ocean currents, El Nina, 90 Oceans, ecc Sea ice Organizational issues, 7-8 Ozone depletion, 1-2, 67, 68-69 chlorine compounds and, 56, 62-63, 66 halocarbons and, 33-46 heterogeneous chemical processes, 32, 48-5S, 56, 76 measurement of, 38-46, 58-59, 64 and Montreal Protocol, 1~17, 19, 31, 36-37

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INDEX Southern Hemisphere levels, 20-21, 22-25, 43, 74-75 temperature changes and, 85, 91, 96 Cc also Antarctic ozone hole Ozone self-healing, 39-40, 68 Ozone Trends Panel, findings, 41, 46, 90 Ozonesondes, 22-23 p Paleoclimatology, sec Ice core data Permafrost, 81, 99, 101 Pickering, S., 49 Planetary waves, 76 Plankton, 31 Polar regions, 64, 89-90 Greenhouse gas effect, numerical models, 98-102 methane in polar ice cores, 79-81 Northern Hemisphere ozone hole, 76-77 stratospheric clouds, 31, 4050, 75-76 ace also Antarctica; Antarctic ozone hole Polar vortex, 29, 30 definition, 25, 31-32 stratospheric clouds, 75 trace gases, 29, 30, 60~2, 63-65 Policy development, 6, 8 ace also International agreements and programs Prediction and predictive models of chlorine compounds in atmosphere, 34, 3038, 58 Greenhouse gas effects and ozone changes in stratosphere, 66-78, Greenhouse gas ejects, numerical, 98-102 of hydroxyl levels in troposphere, 83 of ozone depletion, 13-15, 17, 58, 68-70 Q Quasi-biennial oscillation, 40-41, 46, 87, 89 121 R Radiosondes, 86, 90 Remote sensing, 26, 79 Research history of, 4-7 methane, requirements, 82-83 requirements, 8-g arc also Atmospheric and climatic models; Measurements and measuring devices; Numerical analyses and models; Prediction and predictive models Rocketsondes, 86 Rowland, F. Sherwood, 33-47, 56 S Salinger, M. J., 89 Satellite measurements, 14, 22, 25, 43, 46, 67, 83, 86, 88 Sea ice, 99, 100, 101 Seasonal variations, 33, 38-39, 41-43 Northern Hemisphere, 63-64, 75 temperature and, 87, 9~91, 99, 100 Cc also Antarctic ozone hole Solar back~catter ultraviolet satellite instrument, 14 Solar-terre~trial interactions, 14, 25, 38-40, 41, 46, 67, 87, 96, 100 Cc also Ultraviolet radiation Solomon, Susan, 26, 27 Southern Hemisphere chlorine compound levels in atmosphere, 33-34 dynamics of atmosphere, 75-76 nitrogen system stability, 65 ozone levels, 20-21, 22-25, 43, 74-75 temperature trends, 89, 90, 96 ace also Antarctica; Antarctic ozone hole Spectrometry, 14, 22, 25, 38, 41, 83 Statistical analyses, 41-45 least squares regression and linear trends, 87-88 Stouffer, R. J., 99, 100 Stoppani, Antonio, 4 Stratosphere chlorine compound levels, 36, 37-38, 48-51, 66-58, 59, 61-64

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122 chlorine nitrate stability, 48-49 circulation within, 12, 13 clouds in, 31,49-50,67,75, 76,98, 101 cooling of, 1, 12, 15, 25, 67,68, 69-71,76,78, 85-96,98,99 greenhouse gas effects and ozone depletion, models, 66-78, 98-102 homogeneous gas-phase catalysis in, 56-59 ice crystals and clouds, 32,43, 49-50,61 moisture in, 67, 73 nitrogen in, 48-49,52-54,57,59, 64-65,67 ozone levels, 39-41,46,67-68 ace also Antarctic ozone hole; Ozone depletion; Ozone self-healing; Polar vortex Stratospheric Aerosol and Gas Experiment, 46 Statospheric greenhouse projections, 66-78 Stratospheric ozone depletion, 10-18 Sulfur compounds, 32, 49,54-55 Sun, Cc Solar-terrestrial interactions Surface temperature, 12,15,55,87, 88-89, 96 Greenhouse gas effect, 85, 99-100 T Temperature, global trends, 85-96 arc also Atmospheric temperature; Surface temperature Time series analyses, 89, 90 Total Ozone Mapping Spectrometer, 22, 25 Trace gases, 25, 29 in polar vortex, 29, 30, 6~62, 63-65 and temperature change, 85 INDEX 8CC ~80 Free radicals; and apecipc trace gases Trenberth, Kenvin E., 85-96 Trichlorolluoromethane, 33-35 Troposphere, 70 dichlorodifluoromethane (CFC-12) and trichlorofluoromethane (CFC-11) levels, 33-35 greenhouse gases in, 66, 98, 99 nitrogen in, 66-67 ozone levels, 46 trace gases, 29 warming, 1, 13, 15, 55, 68, 72-75, 76, 89, 98, 99 Tang, K. K., 29, 30 U Ultraviolet radiation, 11-12, 15, 87 and antarctic ozone hole, 22, 24, 31 and heterogeneous chemistry of atmosphere, 53 and ozone levels, 39-40, 68 solar backscatter ultraviolet satellite instrument, 14 Umkehr network, 14, 46, 67 Upper atmosphere, arc Stratosphere V Vernadaky, Vladimir, 4, 5 Volcanic eruptions and dust, 32, 54-55, 87, 89, 90 W Washington, W. M., 100 Watson, Robert T., 19-32 Wetlands, 79, 81, 83 Wind, 76 quasi-biennial oscillation, 40-41, 46, 87 World Meteorological Organization, 16