Tracking aerosols and SO 2 clouds from the Raikoke eruption: 3D view from satellite observations

Abstract. The June 21, 2019 eruption of the Raikoke volcano (Kuril Islands, Russia, 48°N, 153°E) produced significant amounts of volcanic aerosols (sulfate and ash) and sulfur dioxide (SO2) gas that penetrated into the lower stratosphere. The dispersed SO2 and sulfate aerosols in the stratosphere were still detectable by multiple satellite sensors for three months after the eruption. For this study of SO2 and aerosol clouds we use data obtained from two of the Ozone Mapping Profiler Suite (OMPS) sensors on the Suomi National Polar-orbiting Partnership (SNPP) satellite: total column SO2 from the Nadir Mapper (NM) and aerosol extinction profiles from the Limb Profiler (LP) as well as other satellite data sets. The LP standard aerosol extinction product at 674 nm has been re-processed with an adjustment correcting for limb viewing geometry effects. It was shown that the amount of SO2 decreases with a characteristic period of 8–18 days and the peak of sulfate aerosol recorded at a wavelength of 674 nm lags the initial peak of SO2 by 1.5 months. Using satellite observations and a trajectory model, we examined the dynamics of unusual atmospheric feature that was observed, a stratospheric coherent circular cloud (CCC) of SO2 and aerosol from July 18 to September 22, 2019.