Soil Moisture and Ocean Salinity
Soil Moisture and Ocean Salinity is a satellite which forms part of ESA's Living Planet Programme. It is intended to provide new insights into Earth's water cycle and climate. In addition, it is intended to provide improved weather forecasting and monitoring of snow and ice accumulation.
History
The project was proposed in November 1998; in 2004 the project passed ESA-phase "C/D" and, after several delays, it was launched on 2 November 2009 from Plesetsk Cosmodrome on a Rockot rocket. The first data from the MIRAS instrument was received on 20 November 2009. The SMOS programme cost is about €315 million. It is led by ESA but with significant input from French and Spanish interests.The satellite is part of ESA's Earth Explorer programme – satellite missions that are performing innovative science in obtaining data on issues of pressing environmental concern. The first is already complete – a mission called GOCE, which mapped variations in the pull of gravity across the Earth's surface. SMOS was the second Explorer to launch; and was followed by CryoSat-2, Swarm (spacecraft), and ADM-Aeolus.
Launcher
The satellite was launched on 2 November 2009 to a nearly circular orbit of 763 km aboard a Rokot, a modified Russian Intercontinental Ballistic Missile SS-19 launched from a decommissioned SS-19 launcher from Northern Russia's Plesetsk Cosmodrome. The SMOS satellite was launched together with the Proba-2, a technology demonstration satellite.Science
The goal of the SMOS mission is to monitor surface soil moisture with an accuracy of 4%. This aspect is managed by the HYDROS project. Project Aquarius will attempt to monitor sea surface salinity with an accuracy of 0.1 psu.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 has an effect on 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.
SMOS has been used to improve hurricane forecasting by collecting hurricane surface-level wind speed data using its novel microwave imaging radiometer, which can penetrate the thick clouds surrounding a cyclone. Hurricanes that have been studied by SMOS include Hurricane Florence, Typhoon Mangkhut, and Typhoon Jebi.