Carbon tetrachloride lifetimes and emissions determined from daily global measurements during 1978–1985

Publication Type:

Journal Article

Source:

Journal of Atmospheric Chemistry, Volume 7, Issue 1, p.35 - 58 (1988)

ISBN:

0167-7764, 1573-0662

URL:

http://link.springer.com/article/10.1007/BF00048253

Keywords:

Atmospheric Protection/Air Quality Control/Air Pollution, atmospheric releases, Carbon tetrachloride, fluorocarbons, Meteorology/Climatology

Abstract:

Seven years of daily gas chromatographic measurements of CCl4 at the five globally distributed ALE/GAGE surface sites are reported. It is determined that CCl4 has been accumulating in the atmosphere at a rate of 1.3±0.1%/yr over the period 1978–1985 and that the releases of CCl4 into the atmosphere have remained fairly constant, with the smallest releases in 1981–1982. Using an inversion scheme based on a nine box model of the atmosphere, we infer a CCl4 lifetime of approximately 40 yr, an inventory on 1 July 1978 of (2.08±0.07)×109 kg and an average rate of release over the period 1978–1985 of (0.9±0.9)×107 kg/yr. These results produce excellent agreement with a release scenario derived from global production estimates for CCl4 and the major CCl4 byproduct, the chlorofluorocarbons. However, to obtain this consistency, it is necessary that our current ALE/GAGE absolute calibration standard be reduced approximately 25% thus bringing it into agreement with measurements by Yokohata et al. (1985) and Hanst et al. (1975).