Sulfate aerosols in the stratosphere affect both the chemistry and the absorption and scattering of radiation in this region. The capacity of stratospheric sulfate aerosols (SSAs) to scatter incoming solar radiation and thus cool climate has prompted proposals for intentional injection of sulfur into the stratosphere.

However, because of its stratospheric chemical role, increased SSA concentrations exacerbate ozone depletion. Recent research indicates that SSAs are more important than previously thought in facilitating polar ozone depletion. The processes governing the transport of sulfur to the stratosphere are poorly quantified.

In collaboration with international partners, Bodeker Scientific extended an existing trajectory model coupled to microphysical and chemical box models to investigate the transport of carbonyl sulfide (COS) and sulfur dioxide (SO₂) from the base of the tropical tropopause layer (TTL), through the TTL, and into the stratosphere. COS and SO₂ are the primary sources for stratospheric sulfate under volcanically quiescent conditions. SO₂ is an important anthropogenic source of sulfur. This research will improve understanding of the mechanisms sustaining the stratospheric aerosol layer and fits perfectly within the scope of the SPARC (Stratosphere-troposphere Processes and their Role in Climate) activity SSiRC (Stratospheric Sulfur and its Role in Climate).

Publication

Kremser, S.; Jones, N.B.; Palm, M.; Lejeune, B.; Wang, Y.; Smale, D. and Deutscher, N.M., Positive trends in Southern Hemisphere carbonyl sulfide, Geophysical Research Letters, doi:10.1002/2015GL065879, 2015.