Open AccessTropospheric concentrations of methylchloroform, CH 3 CCl 3 , in January 1978 and estimates of the atmospheric residence times for hydrohalocarbons
Author(s) -
Yoshihiro Makide,
F. S. Rowland
Publication year - 1981
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.78.10.5933
Subject(s) - troposphere , atmospheric sciences , residence time (fluid dynamics) , temperate climate , volume (thermodynamics) , radical , atmospheric chemistry , chemistry , environmental chemistry , environmental science , climatology , ozone , geology , biology , physics , ecology , organic chemistry , thermodynamics , geotechnical engineering
The ground level tropospheric concentrations of CH3 CCl3 were measured from 55°N to 53°S during the time period around Jan. 1, 1978. The northern temperate zone concentration of CH3 CCl3 averaged 94.6 ± 4.0 × 10-12 by volume. The southern temperate zone concentration averaged 65.2 ± 1.3 × 10-12 , for a worldwide average of 80 × 10-12 by volume. The ratio of concentrations between the two zones is 1.45 ± 0.07. The observed CH3 CCl3 concentrations correspond to 0.52 ± 0.05 times the atmospheric release to that date, corresponding to an atmospheric residence time of 6.9 ± 1.2 yr. The atmospheric residence times for 22 other hydrohalocarbon molecules were estimated in comparison to that of CH3 CCl3 through the relative rates of reaction with OH radicals.