Validation of SMOS measurements over ocean and improvement of sea surface emissivity modelat L band

Abstract

SMOS (Soil Moisture and Ocean Salinity) satellite, launched in November 2009, carries the first interferometric radiometer at L band (1.4GHz) in orbit. Over the open ocean and for moderate wind speeds, SMOS brightness temperatures (TB) are at first order consistent with simulated TB of theoretical pre-launch models implemented in the ESA Level 2 Ocean Salinity processor. However, we found large discrepancies between measurements and model simulations when wind speed is above 12 ms−1. A new set of parameters for a sea wave spectrum and a foam coverage model that can be used for simulating L-band radiometer data over a large range of wind speed is proposed based on the deduced wind induced component from SMOS data. The quality of SMOS retrieved SSS with the new emissivity model is estimated by comparing it with WOA05 climatological SSS.