Observations of land surface temperature and its relationship to soil moisture during SGP99

Surface temperature is a key factor in determining the land surface heat and water balance. Both surface temperature and soil moisture vary spatially according to soil type, land cover, and land use and temporally with the time of day and season of the year making their observation and estimation extremely difficult. The use of satellite data has become important in making temperature and soil moisture observations due to its large spatial and repeat temporal coverage. Global estimates of soil moisture require the availability of a space-based sensor. In order to achieve higher spatial and temporal resolution with spaced based sensors (passive microwave radiometers), connections must be made between the more frequently observed surface temperature and the soil moisture observations. The correlation of surface and subsurface temperature with soil moisture as well as with other meteorological data is vital for future experiments involving these parameters at regional scales using remote sensing techniques. The main focus of this paper is to analyze the change in surface temperature and soil moisture during a dry-down period, and to examine vegetation affects on surface and subsurface temperature and soil moisture. The data analyzed in this paper were collected during the Southern Great Plains 1999 Hydrology Experiment (SGP99) in Oklahoma.