Three-dimensional transport and concentration of SF6 - A model intercomparison study (TransCom 2)

Abstract

Sulfur hexafluoride (SF6) is an excellent tracer of large-scale atmospheric transport, because it has slowly increasing sources mostly confined to northern midlatitudes, and has a lifetime of thousands of years. We have simulated the emissions, transport, and concentration of SF6 for a 5-year period, and compared the results with atmospheric observations. In addition, we have performed an intercomparison of interhemispheric transport among 11 models to investigate the reasons for the differences among the simulations. Most of the models are reasonably successful at simulating the observed meridional gradient of SF6 in the remote marine boundary layer, though there is less agreement at contin..