Evaluation of a Microwave Emissivity Module for Desert Regions With CMEM

Abstract

To overcome deficiencies of current state-of-the-art L-band microwave emission models a microwave emissivity parameterization for desert regions, as derived by Grody and Weng (2008) using dense media theory, has been implemented in European Centre for Medium-Range Weather Forecasts' Community Microwave Emission Modeling platform (CMEM). Simulations of L-Band brightness temperatures were conducted over Africa for 2013 using the default CMEM parameterization of the soil dielectric constant from Wang and Schmugge, and using the desert emissivity parameterization from Grody and Weng. Results are evaluated against Soil Moisture and Ocean Salinity mission data. The Grody and Weng parameterization shows clear improvements over dry soil in arid areas with reduced bias and root-mean-square deviations at both polarizations. However deficiencies for semi-arid areas, where the bare soil model of Wang and Schmugge shows best results in rainy conditions, suggest that hybrid implementation combining soil dielectric and desert emissivity models should be investigated for global scale applications.