Development of a Chinese land data assimilation system: its progress and prospects

The Objective of land data assimilation is to merge multi-source observations into the dynamics of land surface model for improving the estimation of land surface states. We have developed a land data assimilation system for China's land territory. In this system, the Common Land Model and Simple Biosphere Model 2 are used to simulate land surface processes. The radiative transfer models of thawed and frozen soil, snow, lake, and vegetations are used as observation operators to transfer model predictions into estimated brightness temperatures. A Monte-Carlo sequential filter, the ensemble Kalman filter, is implemented as data assimilation method to integrate modeling and observation. The system is capable of assimilating passive microwave remotely sensed data such as special sensor microwave imager (SSM I), TRMM microwave imager (TMI), and advanced microwave scanning radiometer enhanced for EOS (AMSRE) and the conventional in situ measurements of soil and snow. A spatiotemporally consistent assim...