Sulfur dioxide flux estimation from volcanoes using Advanced Spaceborne Thermal Emission and Reflection Radiometer—a case study of Miyakejima volcano, Japan

Abstract

A method is described for estimating the two-dimensional spatial distribution of volcanic SO 2 using thermal infrared image data acquired by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). The author proposes a new method to estimate wind velocity and plume height using an along-track stereoscopic pair image. Volcanic SO 2 flux can be estimated from the spatial distribution of SO 2 and wind velocity. Since ASTER has both the Thermal Infrared Radiometer (TIR) and stereoscopic viewing function in the along-track direction, the volcanic SO 2 flux can be estimated from the ASTER data alone. These methods are applied to the Miyakejima volcano, Japan. The SO 2 flux derived from ASTER is around 5×10 4 ton/day (580 kg s −1), which is slightly larger than the value derived from COSPEC. The plume height estimation error may cause this disagreement because the SO 2 estimation procedure is very sensitive to the plume height.