Improved hourly estimate of aerosol optical thickness over Asian land by fusing geostationary satellites Fengyun-4B and Himawari-9

Yueming Cheng; Tie Dai; Daisuke Goto; Lin Chen; Yidan Si; Hiroshi Murakami; Mayumi Yoshida; Peng Zhang; Junji Cao; Teruyuki Nakajima; Guangyu Shi

doi:10.1016/j.scitotenv.2024.171541

Improved hourly estimate of aerosol optical thickness over Asian land by fusing geostationary satellites Fengyun-4B and Himawari-9

Sci Total Environ. 2024 May 1:923:171541. doi: 10.1016/j.scitotenv.2024.171541. Epub 2024 Mar 5.

Authors

Yueming Cheng¹, Tie Dai², Daisuke Goto³, Lin Chen⁴, Yidan Si⁴, Hiroshi Murakami⁵, Mayumi Yoshida⁶, Peng Zhang⁴, Junji Cao⁷, Teruyuki Nakajima⁸, Guangyu Shi⁷

Affiliations

¹ State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China; Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing, China.
² State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China; Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing, China. Electronic address: daitie@mail.iap.ac.cn.
³ National Institute for Environmental Studies, Tsukuba, Japan.
⁴ National Satellite Meteorological Center (National Centre for Space Weather), Innovation Center for FengYun Meteorological Satellite (FYSIC), Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites/Key Laboratory of Space Weather, China Meteorological Administration, Beijing, China.
⁵ Earth Observation Research Center, Japan Aerospace Exploration Agency, Tsukuba, Japan.
⁶ Remote Sensing Technology Center of Japan, Tsukuba, Japan.
⁷ State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China.
⁸ Tokyo University of Marine Science and Technology, Tokyo, Japan.

PMID: 38453084
DOI: 10.1016/j.scitotenv.2024.171541

Abstract

Asian over-land aerosols are complexities due to a mixture of anthropogenic air pollutants and natural dust. The accuracy of the aerosol optical thickness (AOT) retrieved from the satellite is crucial to their application in the aerosol data assimilation system. Fusion of AOTs with high spatiotemporal resolution from next-generation geostationary satellites such as Fengyun-4B (FY-4B) and Himawari-9, provides a new high-quality dataset capturing the aerosol spatiotemporal variability for data assimilation. This study develops a complete fusion algorithm to estimate the optimal AOT over-land in Asia from September 2022 to August 2023 at 10 km × 10 km resolution with high efficiency. The data fusion involves four steps: (1) investigating the spatiotemporal variability of FY-4B AOT within the past 1 h and 12 km radius calculation domain; (2) utilizing the aerosol spatiotemporal variability characteristics to estimate FY-4B pure and hourly merged AOTs; (3) performing bias corrections for FY-4B and Himwari-9 hourly merged AOT for different observation times and seasons considering pixel-level errors for each satellite; (4) fusing the bias-corrected FY-4B and Himawari-9 hourly merged AOT based on maximum-likelihood estimation (MLE) method. Compared to the original FY-4B AOT, validation with AERONET observation confirms that the root mean square error (RMSE) of hourly merged FY-4B AOT decreases by around 40.6 % and the correlation coefficient (CORR) increases by about 27.8 %. Compared to FY-4B and Himawari-9 merged AOT, the fused AOT significantly decreases (increases) RMSE (CORR) by around 24.7 % (7.3 %) and 20.2 % (5.6 %). In addition, fused AOT is double the number of single-sensor merged AOT. Fusion aerosol map accurately describes the spatial and temporal variations in Asian regions controlled by air pollution and dust storms. Further studies are required for other landscapes with different satellite combinations to promote the application in the data assimilation system.

Keywords: Aerosol optical thickness; Asian aerosol spatiotemporal variability; Data fusion; Fengyun-4B; Geostationary satellite; Himawari-9.