Global distributions of carbonyl sulfide in the stratosphere

July 26, 2008 - Carbonyl sulfide (OCS), the most abundant sulfur-containing gas in the atmosphere, is important to biological nutrient cycles. Emitted by volcanoes and deep-sea vents, OCS is transported to the stratosphere where it can react with atomic oxygen or hydroxyl ions to ultimately form sulfate aerosol particles, which in the stratosphere scatter incoming solar radiation away from Earth and thus are important to regulating the Earth's energy budget. Recent research also suggests that knowledge of OCS concentrations can help constrain calculations of gross primary production, which is important to calculating carbon budgets. However, despite a wealth of global tropospheric measurements of OCS, stratospheric observations are sparse, restricting scientists' understanding of the full role of OCS in Earth systems. Using OCS vertical profiles retrieved by Canada's Atmospheric Chemistry Experiment (ACE) satellite, Barkley et al. (2008) examine the seasonality of global OCS distributions in the upper troposphere and stratosphere. Because tracer gases in the stratosphere are linearly correlated, the authors used concurrent ACE measurements of certain chlorofluorocarbons zto derive a robust estimate of the stratospheric lifetime of OCS.

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Barkley, Michael P., Paul I. Palmer, Chris D. Boone, Peter F. Bernath, and Parvadha Suntharalingam (2008), Global distributions of carbonyl sulfide in the upper troposphere and stratosphere, Geophysical Research Letters, Vol. 35, L14810, doi:10.1029/2008GL034270 (PDF).