Soil Moisture and Remote Sensing

Soil moisture—the water held in the upper layers of the ground—shapes how rainfall becomes runoff, how crops grow, and how heat moves between the land surface and atmosphere, making it one of the more consequential variables in the Earth system. Satellites now allow researchers to estimate soil moisture across the globe by measuring the microwave radiation emitted or reflected by the ground, since wet and dry soils behave differently at those wavelengths. These raw satellite retrievals are then combined with hydrological models through data assimilation, a process that blends observations with physics-based simulations to produce more accurate and continuous estimates than either source could provide alone. Active research questions include how to account for the striking spatial variability of soil moisture—which can change dramatically over just a few meters—and how to validate global satellite products in regions where ground-based sensors are sparse or absent.

Works

358,936

Total citations

702,745

Keywords

Remote SensingSoil MoistureSatellite ObservationsData AssimilationHydrological ModelingGlobal Monitoring