The hourly volcanic SO2 column density and physical characteristics using Geostationary Environment Monitoring Spectrometer (GEMS) measurements

The Geostationary Environment Monitoring Spectrometer (GEMS) onboard the Geostationary Korea Multi-Purpose Satellite-2B (GEO-KOMPSAT-2B) satellite observes the hourly volcanic SO2 over Asia. In this study, the various physical characteristics of volcanic plumes have been investigated based on hourly volcanic SO2 measurements. The transport direction, path and speed, and altitude of volcanic SO2 plume emitted from Nishinoshima in Japan, Etna in Italy, and Dukono located in Halmahera, Indonesia were calculated. The SO2 plume from Nishinoshima, Japan, moved westward at a maximum speed of 57 km/h on August 4, 2020. The SO2 plume generated from Etna was observed to move over China using both GEMS and TROPOMI, and moved at an altitude of 11–14 km and a speed of 162–190 km/h. In the case of the SO2 plume from the Dukono volcano flowed into an average of 3.6 Mg of SO2 per hour to the cities of nearby islands. GEMS can be utilized for an improvement in the prediction accuracy of SO2 plume transport using a chemical transport model due to the availability of hourly volcanic SO2 height information. In addition, hourly observations of SO2 concentrations are expected to protect SO2 exposure through rapid forecasting for people in cities around the volcano.