Soil Moisture and Ocean Salinity Satellite - Science

Science

The goal of the SMOS mission is to monitor surface soil moisture with an accuracy of 4% (at 35–50 km spatial resolution). This aspect is managed by the HYDROS project. Project Aquarius will attempt to monitor sea surface salinity with an accuracy of 0.1 psu (10–30 day average and a spatial resolution of 200 km x 200 km).

Soil moisture is an important aspect of climate, and therefore forecasting. Plants transpire water from depths lower than 1 meter in many places and satellites like SMOS can only provide moisture content down to a few centimeters, but using repeated measurements in a day, the satellite can extrapolate soil moisture. The SMOS team of ESA hope to work with farmers around the world, including the United States Department of Agriculture to use as ground-based calibration for models determining soil moisture, as it may help to better understand crop yields over wide regions.

Ocean salinity is crucial to the understanding of the role of the ocean in climate through the global water cycle. Salinity in combination with temperature determine ocean circulation by defining its density and hence thermohaline circulation. Additionally, ocean salinity is one of the variables that regulate CO₂ uptake and release and therefore control the oceanic carbon cycle.

Information from SMOS is expected to help improve short and medium-term weather forecasts, and also have practical applications in areas such as agriculture and water resource management. In addition, climate models should benefit from having a more precise picture of the scale and speed of movement of water in the different components of the hydrological cycle.