The European SMOS for large-scale water balance and climate modelling studie

The European Soil Moisture and Ocean Salinity (SMOS) mission, after some delay now planned for launch late 2008, will carry a two-dimensional L-band (1.4 GHz) microwave interferometric radiometer with a revisit time smaller than 3 days to retrieve soil moisture (and ocean salinity) at global scale with a spatial resolution of similar to 30km. Soil moisture plays a crucial role in the terrestrial hydrological cycle and its timely and repetitive retrieval is essential for medium term meteorological modelling, hydrological modelling and modelling of several other climate related processes such as vegetation biomass production and CO2 assimilation. Repetitive monitoring of soil moisture fields at regional scales, also are important for understanding changes in the hydrological processes at different time scales. This paper gives some insight into the potential capabilities of SMOS and addresses some issues concerning surface heterogeneity and its consequences for the precision of soil moisture retrieval