5 Years of Envisat Asar Soil Moisture Observations in Southern German

Soil moisture is a key variable for the water and energy exchanges at the land surface. The determination of soil moisture dynamics from space is one of the most prominent, but also most challenging applications for recent active microwave sensor systems. Since the launch of ENVISAT ASAR, more than 4 years of data is available for the retrieval of soil moisture information. The wide area coverage of ASAR allows for soil moisture retrievals for large areas. The present study investigates a long term time series of ASAR soil moisture products. The ENVISAT soil moisture data is compared against a soil moisture climatology, simulated by a land surface model within a mesoscale watershed in Southern Germany. The relationship between the simulated and observed soil moisture is quantified and the potential for the integration of ASAR information into the LSM is outlined.