Geoscience Reference
In-Depth Information
Fig. 3 Accumulated soil water increments (in mm) in the first metre of soil for August 2009, with the OI
(top) and EKF (bottom) analyses
EKF errors, showing that the EKF soil moisture analysis has a slight positive impact on the
2-m temperature forecast.
3.3 Use of Satellite Data to Analyse Soil Moisture
In the past few years, several new space-borne microwave sensors have been developed to
estimate soil moisture from space. They provide spatially integrated information on surface
soil moisture at a scale relevant to NWP models. The active sensor ASCAT on MetOp was
launched in 2006 (Bartalis et al.
2007
). The EUMETSAT (European Organisation for the
Exploitation of Meteorological Satellites) ASCAT surface soil moisture product is the first
operational soil moisture product. It is available in near-real time, and it has been moni-
tored operationally at ECMWF since September 2009 (de Rosnay et al.
2012
). Scipal et al.
(
2008
) evaluated the impact of scatterometer soil moisture products (from the European
Remote-Sensing ERS) data assimilation in a simple nudging scheme. They showed that,
compared to the model “open-loop” (without data assimilation), ASCAT soil moisture data
