Can Subdaily LST Be Constructed in High-Latitude Regions Using Polar Orbiting Satellites?

This study introduces a new method for constructing subdaily land surface temperatures (LSTs) in northern high-latitude areas. The method is based on 1) an integration of observations from multiple satellites-sensors, including Moderate Resolution Imaging Spectroradiometer (MODIS) and Visible Infrared Imaging Radiometer Suite (VIIRS); and 2) the use of swath data to more comprehensively utilize the information content available from overlapping events from each platform within a day. The initial validation phase demonstrated a comparably high performance for LSTs among different products with a root mean square error (RMSE) at approximately $3~^{\circ }$ C. Subsequently, the results confirmed that more than 23 observations per day at 70°N could be achieved, almost quadrupling the observation frequency achieved with twice-daily LST products combining MODIS and VIIRS. At one of the sample sites, the subdaily LST was clearly identified as a near-hourly temporal variation, and the gaps in the early morning and late afternoon were effectively filled.