SMOS - Applications and Mission Performance Evaluation
Drusch, Matthias1; Mecklenburg, Susanne2
1ESA, NETHERLANDS; 2ESA, ITALY
SMOS is ESA's water mission observing key-elements of the Earth's water cycle. It features a novel instrument - MIRAS - that is the first synthetic aperture L-band radiometer ever operated on an EO space mission. High quality measurements have been made since 2009 and operationally delivered to a large user community. SMOS is also the first Earth Explorer mission with a dedicated Near-Real-Time processing chain for its Level 1 observations in the operational ground segment. So far, SMOS is performing very well according to the underlying mission requirements for the satellite and the ground segment.
Over land, polarized L-band brightness temperatures have been routinely monitored by ECMWF as part of the operational quality control. In parallel, the new Kalman filter based surface data assimilation system has been integrated and optimized to accommodate - for the first time - satellite observations in the soil moisture analysis. Selected results on the impact of SMOS in the forecasting system will be presented together with a brief summary on the technical changes in the task scheduling.
Due to the substantial changes in the dielectric properties the freezing and thawing of soils can also be monitored and a frost depth indicator can be derived from the Level 1 brightness temperatures. A first thaw / frost product has been extensively validated over Finland. It has been found that three frost depth classes (0-5, 5 - 10, > 10 cm) can be distinguished. Imagery for the 2010 - 2011 period also showed the late onset of winter in 2011 as indicated through a delayed soil freezing in Northern Europe.
Over ocean, SMOS observations have been used to infer surface wind speeds under hurricane conditions. Data over hurricane Igor from September 2010 revealed that surface wind speeds estimated from SMOS correlate very well with the major surface wind features; in particular the radii of 34, 50, 64 knots and of maximum winds were found very consistent with model outputs. It was concluded, that SMOS brings added value information with respect to METOP/ASCAT.
In Polar Regions, sea ice thickness has been successfully derived up to a depth of 0.5 cm. The data are in good agreement with fractional ice coverage derived from passive microwave sensors operating at higher frequencies and ice thickness estimates obtained through MODIS for the Kara Sea. Based on SMOS, a daily ice product is being produced operationally from 2013 onwards with a 24-hour latency.