Publications

Jin, JQ; Li, J; Wong, MS; Lee, KH; Nichol, JE; Chan, PW (2025). Development of an aerosol optical depth retrieval algorithm based on an improved scattering angle scheme for Advanced Himawari Imager observations. ATMOSPHERIC RESEARCH, 316, 107944.

Abstract
The Advanced Himawari Imager carried by the Himawari-8/9 geostationary satellite provides an effective tool for high-temporal-resolution aerosol monitoring with 10-min temporal resolution. Aerosol optical depth (AOD), as a crucial parameter for characterizing aerosols, is typically retrieved using physical-based algorithms that rely on prior assumptions about surface reflectance and aerosol models. However, these assumptions may not satisfy the complex land and atmospheric circumstances. This study develops a new AOD retrieval algorithm that improves the accuracy of surface reflectance and aerosol model by leveraging the time-series geostationary observations and aerosol properties clustered from precise ground-based measurements. AOD retrievals for 2022 to 2023 were conducted for southern China (mainly in Guangdong province), and validated against ground measurements from AErosol RObotic NETwork (AERONET) and Sun-sky radiometer Observation NETwork (SONET). The results are also compared with aerosol products from the MODerate resolution Imaging Spectroradiometer (MODIS). The retrieval results showed high consistency with AERONET/SONET, achieving a correlation coefficient of 0.74, RMSE of 0.18, and over 52 % of retrievals within the expected error envelopes (EE) of +/-(0.05 + 15 %). In comparison, the Japan Aerospace Exploration Agency (JAXA) AOD products have a lower correlation coefficient of 0.232, RMSE of 0.330, and only about 30 % of retrievals within the EE of +/-(0.05 + 15 %). Furthermore, the proposed algorithm outperforms MODIS in terms of accuracy over their common retrievals. The algorithm based on a newly developed scattering scheme improves the retrieval accuracy at different times and can show aerosol diurnal variations in south China.

DOI:
10.1016/j.atmosres.2025.107944

ISSN:
1873-2895