Recent advances in downscaling soil moisture from satellite to field scale

Abstract:

In the past few years there have been numerous methods that have been used to downscale the coarse spatial resolution soil moisture data obtained from passive microwave satellite sensors. Typical spatial resolutions from these sensors (as they are limited by antenna size) are 10s of kilometers. Field scale data at kilometer or sub-kilometer scale are obtained by couple of methods (a) Use of the thermal inertia relation between soil moisture and surface temperature modulated by vegetation (b) Relationship between soil moisture and evaporation (c) Change detection using high spatial resolution active radar data. Field experiments in support of satellite and aircraft experiments have resulted in better validation methodology. These experiments also include various in-situ networks such as the USDA-ARS SCAN. In this presentation we will present examples from all these methods and discuss validation plans for the Soil Moisture Active Passive (SMAP) mission using data from SMEX02 and SMAPVEX12.