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Detailed Reference Information |
Simmonds, P.G., O'Doherty, S., Huang, J., Prinn, R., Derwent, R.G., Ryall, D., Nickless, G. and Cunnold, D. (1998). Calculated trends and the atmospheric abundance of 1,1,1,2-tetrafluoroethane, 1,1-dichloro-1-fluoroethane, and 1-chloro-1,1-difluoroethane using automated in-situ gas chromatography-mass spectrometry measurements recorded at Mace Head, Ireland, from October 1994 to March 1997. Journal of Geophysical Research 103: doi: 10.1029/98JD00774. issn: 0148-0227. |
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The first in-situ measurements by automated gas chromatograph-mass spectrometer are reported for 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1-dichloro-1-fluoroethane, (HCFC-141b), and 1-chloro-1,1-difluoroethane, (HCFC-142b). These compounds are steadily replacing the chlorofluorocarbons (CFCs) as refrigerants, foam-blowing agents, and solvents. The concentrations of all three compounds are shown to be rapidly increasing in the atmosphere, with 134a increasing at a rate of 2.05¿0.02 ppt yr-1 over the 30 months of observations. Similarly, 141b and 142b increased at rates of 2.49¿0.03 and 1.24¿0.02 ppt yr-1, respectively, over the same period. The concentrations recorded at the atmospheric research station at Mace Head, Ireland, on January 1, 1996, the midpoint of the time series, were 3.67 ppt (134a), 7.38 ppt (141b), and 8.78 ppt (142b). From these observations we optimally estimate the HCFC and HFC emissions using a 12-box global model and OH concentrations derived from global 1,1,1-trichloroethane (CCl3CH3) measurements. Comparing two methods of estimating emissions with independent industry estimates shows satisfactory agreement for 134a and 141b, while for 142b, industry estimates are less than half those required to explain our observations. ¿ 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, Atmospheric Composition and Structure, Troposphere—constituent transport and chemistry, Global Change, Atmosphere (0315, 0325) |
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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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