A quantitative model of soil moisture and instantaneous variation of land surface temperature

Surface soil moisture is a key variable in many hydrological, climatological and ecological processes. Different types of remote sensing systems are currently used to infer soil moisture at different spatial and temporal scales, each with its specific characteristics and limitations. Using AMSR-E soil moisture and MODIS surface temperature (Ts) product, the authors discuss the relationship between the variation rate of land surface temperature and surface soil moisture. Selecting the plains region of Central United States as the study area, the authors propose the distribution triangle of the variation rate of land surface temperature and soil moisture, which is learned from the Ts-NDVI feature space theory. The range of soil moisture is lessening as the increase of instantaneous variation rate of land surface temperature, and the soil moisture value is going down as well. In this paper, Temperature Variation and Vegetation Index (TVVI), a new index containing the information of temperature variation and vegetation, is introduced. The authors also prove that TVVI and soil moisture show a steady relationship of exponential function, and build a quantitative model of soil moisture(SM) and instantaneous surface temperature variation(V_Ts).