Evaluation of the Community Microwave Emission Model Coupled with the Community Land Model over East Asia

The Community Microwave Emission Model (CMEM) developed by the European Centre for Medium- Range Weather Forecasts (ECMWF) can provide a link between surface states and satellite observations and simulate the passive microwave brightness temperature of the surface at low frequencies (from 1 GHz to 20 GHz). This study evaluated the performance of the CMEM coupled with the Community Land Model (CLM) (CMEMCLM) using C-band (6.9 GHz) microwave brightness temperatures from the Advanced Microwave Scanning Radiometer on Earth Observing System (AMSR-E) over East Asia. Preliminary results support the argument that the simulated brightness temperatures of CMEM-CLM from July 2005 to June 2010 are comparable to AMSR-E observational data. CMEM-CLM performed better for vertical polarization, for which the root mean square error was approximately 15 K, compared to over 30 K for horizontal polarization. An evaluation performed over seven sub-regions in China indicated that CMEM-CLM was able to capture the temporal evolution of C-band brightness temperatures well, and the best correlation with AMSR-E appeared over western Northwest China (over 0.9 for vertical polarization). However, larger biases were found over southern North China and the middle and lower reaches of the Yangtze River.