WRF-Chem modeling of sulfur dioxide emissions from the 2008 Kasatochi Volcano

We use the Weather Research Forecasting with Chemistry (WRF-Chem) model to simulate the evolution, dispersion and conversion of the sulfur dioxide (SO2) plume generated by the 2008 eruption of Kasatochi Volcano in Alaska, USA. About 1.7 Tg of SO2 were dispersed into the atmosphere during three distinct explosive events. Stratospheric sulfur dioxide conversion chemistry is detailed and model output is compared to remote sensing retrievals from the Ozone Monitoring Instrument (OMI). WRF-Chem generated SO2 column densities and plume locations similar to those from OMI retrievals as the plume traveled from the North Pacific through the continental United States and Canada. Analysis of SO2 conversion established an eight day lifetime of SO2 for the Kastaochi plume, which is a slightly shorter lifetime than derived by other modeling methods.