The study of aerosol optical properties retrieval using Advanced Himawari Imager onboard a HIMAWARI-8 satellite

Japan Meteorological Agency (JMA) successfully launched the next-generation geostationary satellite called Himawari-8 in 7 October 2014 and started a formal operation in 7 .July 2015. The Advanced Himawari Imager (AHI) sensor has 16 channels (from *** to *** nm), is the next-generation geostationary satellite that observes the entire Earth every 10 minutes. This study attempts to retrieve the aerosol optical properties based on the spectral matching method, with using four visible and near infrared channels (470, 510, 640, 860nm) of the AHI sensor. This method requires the preparation of look-up table (LUT) approach, to retrieve aerosol optical properties through inversion process using the Radiative Transfer Model. The retrieved aerosol optical depth (AOD) from the AHI sensor shows a rather high correlation (R=0.896) with AODs from other geostationary satellite measurements such as Geostationary Ocean Color Imager (GOCI). But the slope and offset of inter-comparison results show that AHI AOD tends to be underestimated. This underestimation seems associated with the uncertainty of the surface reflectance. We also perform an inter-comparison of the top of atmospheric (TOA) reflectances using several satellite AOD measurements such as the AHI, GOCI, and MODerate resolution Imaging Spectro-radiometer (MODIS) AODs. Since AHI tends to show lower AODs than GOCI and MODIS, we first carry out the cross-calibration process and then retrieve the TOA reflectance again. After cross-calibration, correlation coefficient of AHI AOD becomes about 0.91 with the slope of 1.023 and offset of 0.025, indicating the improved auality of AHI AOD.