中文摘要：

利用中国区域地面气象要素驱动数据集（China Meteorological Forcing Dataset,CMFD）,驱动中国科学院大气物理研究所陆面数据同化系统（LDAS-IAP/CAS-1.0）,得到了2003—2010年中国区域土壤湿度数据集,同时不考虑同化卫星遥感亮温数据,直接驱动CLM3.0模拟了2003—2010年中国区域土壤湿度时空变化。将二者土壤湿度模拟结果、地面土壤湿度观测值、美国国家环境预报中心（NCEP）气候再分析数据（CFSR）、基于主动和被动微波传感器的全球土壤湿度数据（SM-MW）进行对比分析发现,考虑同化卫星遥感亮温后与不考虑同化模拟的土壤湿度空间分布有明显差异。将模拟、同化土壤湿度值与观测值对比发现,同化后的青海、甘肃、宁夏和陕西地区土壤湿度较模拟结果有一定的改善。相对于CFSR再分析数据和SM-MW遥感反演数据,模拟和同化土壤湿度值在35°N以南对土壤湿度空间分布的细节刻画更为细致。同化卫星遥感亮温数据后,从2003—2010年土壤湿度四季和年平均空间分布看出,土壤湿度空间分布从西北向东南增加。东北、江淮地区及青藏高原为土壤湿度高值区,新疆和内蒙古为土壤湿度低值区。从变化趋势来看,内蒙古、青藏高原和新疆南部年平均土壤湿度呈增加趋势,其他地区以减小趋势为主。

英文摘要：

In order to validate the ability of The Land Data Assimilation System, and provide references for de- velopment and application of the system. The Land Data Assimilation System of Institute of Atmospheric Phys- ics, Chinese Academy of Sciences （LDAS-IAP/CAS-1. 0）driven by the china meteorological forcing dataset （CMFD） was used to obtain soil moisture （SM） data from 2003 to 2010 over China. Without considering the as- similation of bright temperature of satellite remote sensing, the community land model version 3. 0 （ CLM3. 0） driven by the same forcing data was used to simulate SM from 2003 to 2010 over China. The two simulated SM, observations, climate forecast system reanalysis （CFSR） of national centers for environmental prediction （NCEP） and global soil moisture data record based on active and passive micro wave sensors（SM-MW） were compared with each other. The results showed that the spatial distribution of simulated SM without considering the assimilation of bright temperature of satellite remote sensing and simulated SM considering the assimilation demonstrated obvious difference. Compared with observations, assimilated SM showed some improvement to simulated SM in Qinghai, Gansu, Ningxia and Shaanxi. The simulated and assimilated SM have more detail de- piction in southern regions of 35~N compared to the other two products. After assimilation of bright temperature of satellite remote sensing, on the basis of the four seasons and annual SM from 2003 to 2010, the spatial distri- butions were characterized by a gradually increasing pattern from the northwest to southeast. From the spatial dis- tribufions, the most humid regions were located in the Northeast China Plain, the Jianghuai region, and the Qinghai-Tibetan Plateau, whereas dry regions were located in Xinjiang and Inner Mongolia. From the variation trend, the annual SM mainly increased in Inner Mongolia, the Tibetan Plateau and southern Xinjiang, and de- creased mainly in other regions.