New generation geostationary satellite nighttime total column ozone retrieval

Ozone is an important trace gas in the atmosphere. Due to the uneven distribution of ground monitoring stations and the lack of spatial continuity, as well as the low time resolution caused by the orbital characteristics of polar-orbiting satellites and the inability of some monitoring instruments to obtain valid data at night, this study utilizes the advantages of the Himawari-8/AHI infrared band at night, which has high temporal and spatial resolution and features a strong ozone absorption band at 9.6μm. Using ERA5 TCO (Total Column Ozone) as label data and choosing the time range of 2019-2021 with the Himawari-8 full-disk as the research area, a nighttime TCO retrieval method based on the FCNN model was developed. This method can provide TCO with a spatial resolution of 2km×2km and a temporal resolution of 10 minutes. The validation accuracy shows Pearson’s r of 0.98, R² of 0.95, RMSE of 10.7DU, and MAE of 7.29DU. The model's retrieval accuracy in different regions was verified, revealing higher retrieval accuracy in low-latitude areas.