Synergistic Cloud-Clearing for GIIRS Radiation Combined With Ground-Based Infrared Sounder Using Transformer

In recent years, the Geostationary Interferometric Infrared Sounder (GIIRS) has provided important data support for space-based and ground-based synergistic observation. However, the cloudy environment can easily affect the data of GIIRS, whose spatial resolution is nearly 16 km. As far as we know, no previous research has specifically investigated a cloud-clearing method for GIIRS in the synergistic observation of space-based and ground-based infrared sounders. Based on specially designed alternate attention blocks (AABs), we propose the Synergistic Cloud-Clearing Transformer (SCCT), which utilizes ground-based Atmospheric Emitted Radiance Interferometer (AERI) clear-sky observations and a single cloudy field of view (FOV) from the GIIRS to perform cloud-clearing for the GIIRS in synergistic observation. This approach eliminates the requirement of imager data and identical cloud properties assumption for adjacent GIIRS FOVs. The model training and verification were conducted based on the FY-4 A/GIIRS and AERI-measured data collected from 2020 to 2021. Results show that in the experiment using simulated clear-sky observation as a baseline, the average RMSE and MRAE of SCCT are reduced by 2.75 and 0.037, respectively, compared to the traditional
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cloud-clearing method. In the experiment using adjacent clear-sky FOV observation as a baseline, the reduction of SCCT on average RMSE and MRAE is 5.876 and 0.058 compared to the traditional method.