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Detailed Reference Information |
Miller, B.R., Huang, J., Weiss, R.F., Prinn, R.G. and Fraser, P.J. (1998). Atmospheric trend and lifetime of chlorodifluoromethane (HCFC-22) and the global tropospheric OH concentration. Journal of Geophysical Research 103: doi: 10.1029/98JD00771. issn: 0148-0227. |
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Concentrations of CHClF2 (HCFC-22) in clean background air collected at Cape Grim, Tasmania, over the period 1978--1996, and at La Jolla, California, over the period 1992--1997, have been measured by oxygen-doped electron capture detection gas chromatography. The mid-1996 dry-air mole fractions and trends were 116.7 parts per trillion (ppt) and 6.0 ppt yr-1 in Cape Grim and 132.4 ppt and 5.5 ppt yr-1 in California, respectively. These observations, together with estimates of industrial emissions, have been fitted to a two-dimensional global atmospheric model by an optimal estimation inversion technique to yield estimated tropospheric and total atmospheric lifetimes for chemical destruction of CHClF2 of 9.1-2.8+4.4 years and 10.0-3.0+4.4 years, respectively. These lifetimes correspond to a temperature- and density-weighed global tropospheric OH abundance of 11.0-3.6+5.0¿105 radical cm-3, which is in statistical agreement with our recent more accurate estimate of OH abundance based on measurements of CH3CCl3. Our analysis suggests that, compared to current industrial estimates, southern hemisphere emissions are higher, global emissions are larger in earlier years and smaller in later years, and, finally, production by nonreporting companies is less. ¿ 1998 American Geophysical Union |
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Abstract |
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Keywords
Atmospheric Composition and Structure, Constituent sources and sinks, Atmospheric Composition and Structure, Troposphere—composition and chemistry, Global Change, Biogeochemical processes, Atmospheric Composition and Structure, Middle atmosphere—composition and chemistry, Atmospheric Composition and Structure, Middle atmosphere—constituent transport and chemistry, Mathematical Geophysics, Modeling |
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Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
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