On the Inter-relationship Between Land Surface Air Temperature and Skin Temperature

Both near-surface air temperature measured at 2 m height and land surface (skin) temperature (LST) are complementary in their contribution to the study of climate change. Near surface daily minimum and maximum air temperatures over land are conventionally obtained by in situ observations at meteorological stations worldwide. Global Historical Climatology Network (GHCN) represents an integrated data base of such daily climate summaries. While the station network is extensive, many land masses are poorly observed. Satellites on the other hand can measure land surface temperatures across the globe at sub-daily timescales albeit under clear sky conditions. In this study we develop an empirical relationship between the near surface air temperature and LST over the Contiguous US by analyzing data on infrared temperature and air temperature over hundreds of US Climate Reference Network (USCRN) sites. Such an inter-relationship will not only help in expanding the coverage of near surface air temperature over data sparse regions of the globe, but also extend satellite remote sensing-based measurements of LST to cover all-sky conditions at sub-daily timescales.