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In stratosphere

The key gas-phase reactions occurring in the stratosphere are generally known. Comprehensive reviews of kinetic data have led to general consensus on the rate parameters that should be used in stratospheric models (91). Nevertheless, discrepancies are stiU apparent when the chemical components of... [Pg.386]

W. B. DeMore and co-workers. Chemical Kinetics and Photochemical Data for Use in Stratospheric Ocyone Modeling Evaluation No. 8, JPL Publ. 87—41, Jet Propulsion Laboratory, Pasadena, Calif., 1987. [Pg.388]

The other global environmental problem, stratospheric ozone depletion, was less controversial and more imminent. The U.S. Senate Committee Report supporting the Clean Air Act Amendments of 1990 states, Destruction of the ozone layer is caused primarily by the release into the atmosphere of chlorofluorocarbons (CFCs) and similar manufactured substances—persistent chemicals that rise into the stratosphere where they catalyze the destruction of stratospheric ozone. A decrease in stratospheric ozone will allow more ultraviolet (UV) radiation to reach Earth, resulting in increased rates of disease in humans, including increased incidence of skin cancer, cataracts, and, potentially, suppression of the immune system. Increased UV radiation has also been shown to damage crops and marine resources."... [Pg.16]

It is only recently that a decrease in stratospheric ozone levels attributable to the CFCs has been observed. In spite of the relatively large natural... [Pg.27]

The Antarctic ozone hole is the result of anthropogenic release of trace gases into the atmosphere (CFCs in particular), causing a decrease in stratospheric ozone and a subsequent increase in solar ultraviolet radiation reaching the earth s surface. [Pg.204]

In summary, biomass burning is a major source of many trace gasses, especially the emissions of CO2, CH4, NMHC, NO,, HCN, CH3 CN, and CH3 Cl (73). In the tropics, these emissions lead to local increases in the production of O3. Biomass burning may also be responsible for as much as one-third of the total ozone produced in the troposphere (74). However, CH3 Cl from biomass burning is a significant source for active Cl in the stratosphere and plays a significant role in stratospheric ozone depletion (73). [Pg.449]

The role of carbon dioxide in the Earth s radiation budget merits this interest in atmospheric CO2. There are, however, other changes of importance. The atmospheric methane concentration is increasing, probably as a result of increasing cattle populations, rice production, and biomass burning (Crutzen, 1983). Increasing methane concentrations are important because of the role it plays in stratospheric and... [Pg.308]

As mentioned previously, N2O plays an important role in stratospheric chemistry by providing the dominant source of NO in the stratosphere (see Section 12.5). What is more difficult to predict is how stratospheric chemistry will change as a result of continued increases in the concentration of atmospheric N2O. Early research suggested that increased N2O would lead to significant reductions in stratospheric O3. However, more current reports suggest that stratospheric NO plays a key role in "protecting" stratospheric O3 from more significant... [Pg.336]

NASA Panel for Data Evaluation, "Chemical Kinetic and Hydrochemical Data for Use in Stratospheric Modeling," Evaluation Number 2, JPL Publication 79-27, April 1979. [Pg.132]

WB DeMore, SP Sander, DM Golden, RF Hampson, MJ Kurylo, CJ Howard, AR Ravishankara, CE Kolb, MJ Molina. Chemical Kinetics and Photochemical Data for Use in Stratospheric Modeling, JPL Publication 97-4. Pasadena NASA JPL, 1997. [Pg.387]

The chlorofluorocarbon compounds of methane and ethane are collectively known as freons. They are extremely stable, unreactlve, non-toxic, non-corrosive and easily liquefiable gases. Freon 12 (CCI2F2) Is one of the most common freons In Industrial use. It Is manufactured from tetrachloromethane by Swarts reaction. These are usually produced for aerosol propellants, refrigeration and air conditioning purposes. By 1974, total freon production In the world was about 2 billion pounds annually. Most freon, even that used In refrigeration, eventually makes Its way Into the atmosphere where It diffuses unchanged Into the stratosphere. In stratosphere, freon Is able to Initiate radical chain reactions that can upset the natural ozone balance (Unit 14, Class XI). [Pg.40]

Similar effects have also been observed in stratospheric nitrous oxide. and 5 0 measurements by Cliff and Thiemens (1997) reveal that stratospheric... [Pg.175]

Baroni M, Thiemens MH, Delmas RJ, Savarino J (2007) Mass-independent sulfur isotopic composition in stratospheric volcanic eruptions. Science 315 84-87 Barth S (1993) Boron isotope variations in nature a synthesis. Geologische Rundschau 82 640-651... [Pg.231]

Clayton RN, Goldsmith JR, Karel KJ, Mayeda TK, Newton RP (1975) Limits on the effect of pressure in isotopic fractionation. Geochim Cosmochim Acta 39 1197-1201 Clayton RN, Onuma N, Grossman C, Mayeda TK (1977) Distribution of the presolar component in Allende and other carbonaceous chondrites. Earth Planet Sd Lett 34 209-224 Clayton RN, Goldsmith JR, Mayeda TK (1989) Oxygen isotope fractionation in quartz, albite, anorthite and caldte. Geochim Cosmochim Acta 53 725-733 Cliff SS, Thiemens MH (1997) The 0/ 0 and 0/ 0 ratios in atmospheric nitrous oxide a mass independent anomaly. Science 278 1774-1776 Cliff SS, Brenninkmeijer CAM, Thiemens MH (1999) First measurement of the 0/ 0 and ratios in stratospheric nitrous oxide a mass-independent anomaly. J Geophys Res 104 16171-16175... [Pg.237]

Rafter TA (1957) Sulphur isotopic variations in nature, P 1 the preparation of sulphur dioxide for mass spectrometer examination, N Z J Sci Tech B38 849 Rahn T, Wahlen M (1997) Stable isotope enrichment in stratospheric nitrous oxide. Science 278 1776-1778... [Pg.264]

Whisnant et al. has developed an online project in computation chemistry that can be used to investigate the role of Cl20 in stratospheric ozone depletion. [Pg.618]

NAS. 1984. Causes and effects of changes in stratospheric ozone update 1983. Washington DC National Academy of Sciences. [Pg.176]


See other pages where In stratosphere is mentioned: [Pg.243]    [Pg.204]    [Pg.204]    [Pg.324]    [Pg.226]    [Pg.277]    [Pg.132]    [Pg.178]    [Pg.448]    [Pg.449]    [Pg.452]    [Pg.623]    [Pg.626]    [Pg.627]    [Pg.248]    [Pg.180]    [Pg.192]    [Pg.174]    [Pg.177]    [Pg.264]    [Pg.296]    [Pg.29]    [Pg.79]    [Pg.1478]    [Pg.202]    [Pg.10]    [Pg.69]    [Pg.84]    [Pg.127]    [Pg.176]    [Pg.289]   


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Stratosphere

Stratospheric

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