摘要
由陆面信息系统(Land Information System,简称LIS)通过NOAH陆面过程模型使用集合卡尔曼滤波开展AMSR-E(Advanced Microwave Scanning Radiometer-Earth Observing System)土壤湿度同化试验,得到2003年中国区域垂直深度为4层、水平空间分辨率为0.25°×0.25°的土壤湿度试验数据。使用农业气象观测站土壤相对湿度和国家生态系统野外科学观测研究站土壤体积含水量对试验结果进行检验,结果表明:同化过程整体上提高了陆面模型的模拟精度,草地生态系统模拟精度高于作物和森林生态系统;有效的同化过程依赖于AMSR-E土壤湿度的准确性;模拟出的土壤湿度空间分布特征与实际相符。同化试验得到的时空相对连续且精度相对准确的土壤湿度数据是气候变化和干旱监测的重要数据基础。
Soil moisture is an important part of the soil, playing an important role in energy and mass exchange between land and atmosphere. It is an important environment factor and the process parameter of hydrolo- gy, meteorology and other researches. In order to accurately depict and understand the interaction between land and atmosphere, precise and high resolution soil moisture contour information is needed. But whether using the objective measurement or numerical prediction of land surface process simulation, soil moisture contour line with spatial-temporal continuum and good precision can＇t be obtained. In order to eliminate the error, data assimilation method （EnKF） is used to process passive microwave inversion products （AM- SR-E） and land surface model （NOAH） outputs, and then shallow soil moisture information is transmitted to deeper soil layers by .land assimilation system （LIS）. These methods are used to calculate soil moisture with high precise, high resolution and low error. Through these methods, 4-1ayer （10 cm, 30 em, 60 cm, 100 cm） soil moisture data with spatial resolution of 0.25° by 0.25° for the year of 2003 are obtained. Agro-meteorological-station soil moisture data and ecological-station data are used to verify the 4-layer soil moisture results. The simulation accuracy of the land surface model is improved when data assimilation method is used, the simulation accuracy in different layers is different, and the accuracy in tl^e grassland e- cosystem is higher than that in crop and forest ecosystems. The spatial characteristics Of assimilation re- sults match with real values, which is high in the southeast and low in the northwest. Assimilation soil moisture data has more detailed information in horizontal scales compared to station data and has more detailed information in vertical scales compared to the passive microwave inversion products. The accuracy of the assimilation process depends on the passive microwave inversion products （AM- SR-E）. However, AMSR-E has stop
出处
《应用气象学报》
CSCD
北大核心
2013年第4期435-445,共11页
Journal of Applied Meteorological Science
基金
公益性行业(气象)科研专项(GYHY201106014)
国家科技支撑计划项目(2008BAC40B03)
国家自然科学基金项目(40705037)
