Atmospheric SO₂ measurements on Project Gametag

Abstract

On the 1978 Global Atmospheric Measurements Experiment of Tropospheric Aerosols and Gases (Gametag) flights, 201 measurements of the tropospheric concentration of SO 2 were made over a latitude range 57°S to 70°N. The area sampled included the central and the southern Pacific Ocean and the western section of the United States and Canada. Sulfur dioxide levels averaged 89±69 pptv in the boundary layer and 122±85 pptv in the free troposphere in the northern hemisphere. In the southern hemisphere, SO 2 concentrations averaged 57±18 pptv in the boundary layer and 90 ± 21 pptv in the free troposphere. The mean concentration of the continental data was 112±79 pptv in the boundary layer and 160±100 pptv in the free troposphere. The SO 2 marine values were 54±19 pptv in the boundary layer and 85±28 pptv in the free troposphere. From a simple chemical model we conclude that a significant amount of background SO 2 may originate from the oxidation of OCS.