Global daily viirs lst product quality evaluation and applications

In this study, we introduce the gridded VIIRS LST product focusing on its quality assessment and applications. The quality assessment is performed using ground observations over various land surface types (e. g., cropland, desert, grassland, shrubland, water, and snow/ice) from five ground observation networks, including Surface Radiation budget network (SURFRAD), Atmospheric Radiation Measurement (ARM), Baseline Surface Radiation Network (BSRN), Programme for Monitoring of the Greenland Ice Sheet (PROMICE), and National Data Buoy Center (NDBC) covering a wide latitude range across the globe. Four years of satellite LST data from 2019 to 2022 were used for validation and the results indicate good agreement with ground observations, with an accuracy ranging from -0.86 K to 0.78 K and RMSE ranging between 1.03 K to 2.36 K. We present statistical and time series analysis including a seasonal variation analysis. Additionally, cross-satellite comparisons were conducted with MYD11A1 LST and VNP21A1 LST product. One day in each month was selected for comparison at a global scale. The results suggest that MYD11A1 has the lowest LST estimates for both daytime and nighttime, while the L3 VIIRS LST is intermediate between MYD11A1 and VNP21A1 during daytime and close to VNP21A1 at nighttime. The gridded LST data has been utilized in many applications, such as a critical input for developing the soil moisture product and global evapotranspiration product with high spatial resolution, and monitoring extreme weather events, etc.