Data assimilation of himawari-8 aerosol observations: Asian dust forecast in June 2015

Abstract

Himawari-8 is a Japanese geostationary weather satellite that was launched in October 2014 and has been in operation since July 2015. Himawari-8 is equipped with an outstanding highperformance imager that has 16 spectral channels (3 for visible, 3 for near-infrared and 10 for infrared wavelengths) with a 10- minute observation interval. We retrieved aerosol optical thickness (AOT) from visible and near-infrared multispectral observations of Himawari-8 and assimilated the AOT data into a global aerosol forecast model with an ensemble Kalman filter system. The data assimilation result was validated by comparison with conventional products derived from polar-orbiting satellite aerosol observations (i.e., Moderate Resolution Imaging Spectroradiometer (MODIS) AOT) of an Asian dust storm in June 2015. The Himawari-8 AOT data assimilation successfully produced an analysis and forecast of the Asian dust that was comparable or superior to those of the MODIS AOT data assimilation. The Himawari-8 aerosol product has a much higher temporal coverage than that of polar-orbiting satellites, which is promising for aerosol data assimilation. This study is a first step in the application of geostationary satellites for aerosol research.