Eugene S. Takle
© 2003
Biomass burning contributes about 10-20% of the sulfur that leads to carbonyl sulfide (COS), a long-lived form of sulfur in the troposphere. Because it is not easily removed from the troposphere, its distribution is relatively uniform with height and therefore allows COS to migrate to the stratosphere where it is converted by photolysis to SO2 and eventually sulfate particles. Notholt et al (2003) find that biomass burning contributes more COS and hence sulfate aerosols than previously thought. Increase in biomass burning in tropical and subtropical Southeast Asia may have offset some of the decrease in atmospheric sulfur due to emissions controls in North America and Europe.
Reference
Notholt, J., Z. Kuang, C P. Rinsland, G. C. Toon, M. Rex, N. Jones, T. Albrecht, H. Deckelmann, J. Krieg, C. Weinzierl, H. Bingemer, R. Weller, and O. Schrems, 2003: Enhanced upper tropical tropospheric COS: Impact on the stratospheric aerosol layer Science, 300, 307-310.