Global trends and annual releases of CCl{sub 3}F and CCl{sub 2}F{sub 2} estimated from ALE/GAGE and other measurements from July 1978 to June 1991

Journal Article · Thu Jan 20 00:00:00 EST 1994 · Journal of Geophysical Research

DOI:https://doi.org/10.1029/93JD02715· OSTI ID:81534

Cunnold, D M; Alyea, F N ^[1]; Fraser, P J ^[2]; Weiss, R F; Miller, B R ^[3]; Prinn, R G ^[4]; Simmonds, P G ^[5]; Crawford, A J ^[6]

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1. Georgia Institute of Technology, Atlanta, GA (United States)
2. CSIRO, Victoria (Australia)
3. Univ. of California, La Jolla, CA (United States)
4. Massachussetts Institute of Technology, Cambridge, MA (United States)
5. Univ. of Bristol (United Kingdom)
6. Oregon Graduate Institute, Beaverton, OR (United States)

Thirteen years of Atmospheric Lifetime Experiment/Global Atmospheric Gases Experiment CCl{sub 3}F and CCl{sub 2}F{sub 2} measurements at five remote, surface, globally distributed sites are analyzed. Comparisons are made against shipboard measurements by the Scripps Institution of Oceanography group and archived air samples collected at Cape Grim, Tasmania, since 1978. CCl{sub 3}F in the lower troposphere was increasing at an average rate of 9.2 ppt/yr over the period July 1978 to June 1988. CCl{sub 2}F{sub 2} was increasing at an average 17.3 ppt/yr in the lower troposphere over the same period. However, between July 1988 and June 1991 the increases of CCl{sub 3}F and CCl{sub 2}F{sub 2} in this region have averaged just 7.0 ppt/yr and 15.7 ppt/yr, respectively. The rate of increase has been decreasing 2.4 ppt/yr{sup 2} and 2.9 ppt/yr{sup 2} over this 3-year period. Based on a recent scenario of the global releases of these compounds and using the new calibration scale SIO 1993, the equilibrium lifetimes are estimated to be 44{sub -10}{sup +17} and 180{sub -81}{sup +820} years for CCl{sub 3}F and CCl{sub 2}F{sub 2}, respectively. Using these lifetime estimates and a two-dimensional model, it is estimated that global releases of these two chlorofluorocarbons in 1990 were 249 {+-} 28 x 10{sup 6} kg for CCl{sub 3}F and 366 {+-} 30 x 10{sup 6} kg for CCl{sub 2}F{sub 2}. It is also estimated that combined releases of these chlorofluorocarbons in 1990 were 21 {+-} 5% less than those in 1986. 34 refs., 12 figs., 9 tabs.

• OSTI ID: 81534
• Journal Information: Journal of Geophysical Research, Vol. 99, Issue D1; Other Information: PBD: 20 Jan 1994
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
29 ENERGY PLANNING AND POLICY
CHLOROFLUOROCARBONS
GLOBAL ASPECTS
MONITORING
BUILDUP
OZONE LAYER
ENVIRONMENTAL EFFECTS
MEASURING INSTRUMENTS
GREENHOUSE GASES
STRATOSPHERE