Soil Moisture and Ocean Salinity Mapping (SMOS)
The Soil Moisture and Ocean Salinity mission provides global maps of soil moisture and ocean salinity. Soil moisture data are urgently required for hydrological studies and data on ocean salinity are vital for improving our undertanding of ocean circulation patterns which will contribute to furthering our knowledge of the Earth's water cycle, and will improve climate, weather and extreme-event forecasting.
Soil Moisture and Ocean Salinity Satellite (SMOS)
(Copyright © ESA)
SMOS demonstrates a new measuring technique by adopting a completely different approach in the field of observing the Earth from space. A novel instrument has been developed that is capable of deriving both soil moisture and ocean salinity by capturing images of emitted microwave radiation around the frequency of 1.4 GHz (L-band). SMOS will carry the first-ever, polar-orbiting, space-borne, 2-D interferometric radiometer.
Although soil only holds a small percentage of the total global water budget, soil moisture plays an important role in the global water cycle as it controls vegetation growth to a large extent. Because in-situ measurements of soil moisture are sparse, more data are urgently required if we are to better our understanding of the water cycle.
The same is true for data on ocean salinity. There are few historical measurement data, and only a small fraction of the ocean is currently sampled on a regular basis. Salinity and temperature determine the density of seawater, and in turn, density is an important factor driving the currents in our oceans. Ocean circulation plays a crucial role in moderating the climate by, for example, transporting heat from the Equator to the poles. Ocean salinity is therefore one of the key variables for monitoring and modeling ocean circulation.