Evaluation of a multi-satellite soil moisture product and the Community Land Model 4.5 simulation in China
B. Jia1, J. Liu1,2, and Z. Xie11State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China 2High Performance Computing Center, Department of Mathematics and Applied Mathematics, Huaihua University, Huaihua, Hunan, China
Received: 05 May 2015 – Accepted for review: 05 May 2015 – Discussion started: 29 May 2015
Abstract. Twenty years of in situ soil moisture data from more than 300 stations located in China are used to perform an evaluation of two surface soil moisture datasets: a microwave-based multi-satellite product (ECV-SM) and the land surface model simulation from the Community Land Model 4.5 (CLM4.5). Both soil moisture products generally show a good agreement with in situ observations. The ECV-SM product has a low bias, with a root mean square difference (RMSD) of 0.075 m3 m-3, but shows a weak correlation with in situ observations (R = 0.41). In contrast, the CLM4.5 simulation, forced by an observation-based atmospheric forcing data, produces better temporal variation of surface soil moisture (R = 0.52), but shows a clear overestimation (bias = 0.05 m3 m-3) and larger RMSD (0.09 m3 m-3), especially in eastern China, caused by inaccurate descriptions of soil characteristics. The ECV-SM product is more likely to be superior in semi-arid regions, mainly because of the accurate retrievals and high observation density, but inferior over areas covered by dense vegetation. Furthermore, it shows a stable to slightly increasing performance in China, except for a decrease during the 2007–2010 blending period. Results from this study can provide comprehensive insight into the performances of the two soil moisture datasets in China, which will be useful for their improvements in merging algorithms or model simulations and for applications in soil moisture data assimilation.
Jia, B., Liu, J., and Xie, Z.: Evaluation of a multi-satellite soil moisture product and the Community Land Model 4.5 simulation in China, Hydrol. Earth Syst. Sci. Discuss., 12, 5151-5186, doi:10.5194/hessd-12-5151-2015, 2015.