Atmospheric Concentrations and Distributions of CF2Cl2, CFCl3 and N2O over Japan between 1979 and 1986

[摘要] Tropospheric and stratospheric air samples have been collected over Japan (33-38°N) since 1978, and analyzed for CF2Cl2, CFCl3 and N2O by a GC-ECD method.Mean volume mixing ratios in the troposphere were 390ppt for CF2Cl2, 238ppt for CFCl3, and 308ppb for N2O in November 1986. Those of CF2Cl2 and CFC13 were increasing at almost constant rates, i.e., 13.5ppt/year for CF2Cl2 and 9.5ppt/year for CFCl3 between January 1979 and November 1986. Those of N2O appear to be increasing at a rate of 2.0ppb/year between December 1982 and November 1986.Volume mixing ratios of CF2Cl2, CFCl3 and N2O in the lower stratosphere (15-28km) decreased with increasing altitude in agreement with the vertical profiles calculated from a one-dimensional photochemical-diffusive model.

[学科分类] 大气科学