Calibration of the span of Himawari-8 AOD products in eastern China

Abstract

ABSTRACT At present, atmospheric aerosol pollution is a major issue in China. Himawari-8 (H8) aerosol products with high temporal resolutions are helpful for achieving real-time monitoring of subtle aerosol variation. However, the H8 aerosol optical depth (AOD) product has been updated three times since its launch, and evaluations of this dataset are scarce at present. To validate its accuracy, this study compared the H8 Level-2 (L2) minute AOD products of all versions with measurements obtained from eight typical sites in eastern China, a high aerosol region, in 2016. The AOD of H8 version 010 underestimated observed AOD by 37%-46% in this region. The overall underestimation of AOD in version 021 still exists (7%-15%). The absolute error of H8 AOD in version 010 symmetrically increased by 0.05 while increasing the observed AOD by 0.1, which was a span error for H8 AOD in version 010. Based on the absolute error linear regression equation, a span error correction was performed in the region. Compared with the AOD of version 021, the span error corrected AOD of version 010 has lower uncertainty (Root Mean Squared Error (RMSE): 0.13-0.39) and higher consistency (s: 0.80-1.2). The underestimation was also further improved (2%-4%).