Daily multi-time monitoring of SLST jointly using FY-3 dawn-dusk and afternoon orbit satellite data with 250 m resolution

Snow/land surface temperature (SLST) has a significant impact on snow melting, metamorphism, and land-atmosphere energy exchange. It is also an important factor that affects outdoor skiing during the Olympic Winter Games (OWG). Currently, there is no daily SLST product at the hundred-meter level to effectively provide OWG services. In this study, Land Surface Emissivity (LSE) was calculated for natural snow, artificial snow cover, and other surface types. Subsequently, a unified algorithm was developed to retrieve the SLST from the 250 m data of the Fengyun-3E (FY-3E) dawn-dusk orbit and Fengyun-3D (FY-3D) afternoon orbit satellite, based on the thermal infrared radiation transfer model. Daily multi-time monitoring (at dawn, noon, and dusk) of SLST was conducted based on the refined SLST products by jointly using FY-3E and FY-3D satellites in the outdoor competition field of the OWG and its surrounding areas. Validation using field-measured data showed that the correlation coefficient was > 91%. The average bias of each site ranges from -1.18K to 1.15K, while the root-mean-square error (RMSE) ranges from 0.78K to 2.19 K.