Interhemispheric gradients of CF₂Cl₂, CFCl₃, CCl₄, and N₂O

Direct, real‐time gas chromatographic measurements of CF 2 Cl 2 , CFCl 3 , CCl 4 , and N 2 O were made at latitudes from 74°N to 62°S aboard a NASA Convair 990 as part of the 1976 NASA CV‐990 Latitude Survey Mission between Alaska and New Zealand. A difference was found in the average mixing ratios of CF 2 Cl 2 and CFCl 3 between the northern and southern hemispheres, but no differences were noted for CCl 4 and N 2 O. The results support some of the previous studies of interhemispheric tropospheric gradients and suggest the lack of any significant tropospheric sinks.