【作者】 邹兰军；

【导师】 高炜； 许小峰； 吴统文；

【作者基本信息】 南京信息工程大学 ， 大气遥感科学与技术， 2007， 博士

【摘要】 开展气候研究需要长时间序列的高质量的资料。我国已经具有众多台站和遥感观测数据，但是目前为止还没有建立我国自己的陆面资料同化系统，缺乏高质量的陆面同化分析数据集。另外，陆面模式作为科学地评估陆地表面变化及陆气相互作用的重要工具，它的发展及性能检验也有赖于可靠的资料，因此建立陆面资料同化系统并利用其为陆面模式提供满足模式要求的相对准确的大气强迫场已经成为亟待解决的问题。本论文的重点围绕充分利用观测资料为陆面模式建立相对准确的大气驱动场，并以此建立陆面资料同化系统展开研究，主要结论有：1．发展了一个三维变分(3DVar)同化系统，通过调整同化系统中背景误差协方差使之适用于陆面模式大气驱动场各个变量的同化，同时该同化系统也能适用于陆面模式中土壤温度、土壤湿度等预报量的同化；2．使用沙漠站观测资料和AMSR-E遥感土壤湿度数据，检验了陆面模式CLM在中国区域土壤温度和土壤湿度等地表变量的模拟能力，研究发现，CLM大体能够把握住中国地区复杂下垫面的水热特征的分布和变化趋势，取得较好的模拟效果；3．为了满足陆面模式需求，基于NCEP再分析资料，提出了一种计算任意时段平均太阳辐射的方案，整理生成了一套可用于模式检验和分析的反映日变化的全球太阳辐射资料集，并验证了资料的可用性。这套资料集补充了太阳辐射观测资料的不足，应用这套资料作为陆面模式CLM的大气驱动场，能够有效改进模式土壤温度的模拟；4．建立了一套同化多源观测信息的日变化降水率资料集。利用NCEP资料的日变化特征，将台站日降水量资料生成日变化的降水率数据，然后，利用3DVar同化系统同化中国区域的多源降水数据(包括国际交换站、Micaps台站和TRMM卫星观测日降水量)，降水率同化后的数据序列作为大气驱动资料能够有效改进土壤湿度的模拟；5．以日变化的太阳辐射资料和同化观测信息的日变化降水率资料集为基础，比较分析了不同大气驱动场对于地表变量模拟的影响，同时产生一套土壤温度、土壤湿度数据集，分析土壤温度和土壤湿度等地表变量的分布及变化规律。通过本文工作，开发了陆面模式大气驱动场各变量的同化系统，建立了一套相对准确的日变化的陆面模式大气驱动场资料集，并应用CLM模式生成了一套土壤温度和土壤湿度数据集，为模式验证和模拟分析提供了基础，为气候变化研究提供了数据支持。更多还原

【Abstract】 Climate studies need long serial of historic data sets of high quality. There aremany station and remote sensing observation data in China, but there are no perfectland data assimilation systems and no assimilated land ananlysis data of high qualityat present. Meanwhile, as an important tool to evaluate land surface change and theatmosphere-land interactions, the development and performances of land surfacemodel rely upon the quality of data, so it is urgent to develop land data assimilationsystem and use it to provide more accurate atmospheric forcing data for land surfacemodels.This study is carried out focusing on providing more accurate atmospheric forcingfor land surface models and developing a land data assimilation system. The mainconclusions can be summarized as follows: 1) A 3DVar assimilation system is developed for assimilating the atmosphericforcing variables respectively by setting background error covariance inassimilation system. This assimilation system can also be used to assimilatepredication variables in land surface models, such as soil temperature and soilmoisture etc.2) Common Land Model (CLM) is validated for land surface variables (includingsoil temperature and soil moisture) over China by using desert observation dataand AMSR-E remote sensed soil moisture data, the results show that CLM cangrasp the distribution and change trends about hydrothermal characteristics overthe complex underlying surface of China region, thus good simulationperformances are achieved.3) A method to compute mean solar radiation at surface in any time interval based onNCEP reanalysis is presented to meet the requirements of land surface model,then a set of diurnal variation of solar radiation data is established, which can beused as data basis for model validation and analysis. The usability of this data setis verified. This data set can compensate the shortage of solar radiationobservations. With this data set applicated as one of the CLM atmosphericforcings, the performance of CLM is markedly enhanced with respect to soiltemperature.4) A precipitation rate data set of diurnal variation with multi-source precipitationdata assimilated is developed. The station observed daily precipitation data areused to generate precipitation rate of diurnal variation based on the diurnal variation of NCEP precipitation rate data, then, the 3DVar data assimilationsystem is used to assimilate precipitation data from different sources (includingInternational exchange station, Micaps and TRMM satellite-observed precipitation)and the newly-build assimilated precipitation rate data can effectively enhance theperformance of CLM with respect to soil moisture as one of the CLM atmosphericforcings.5) The atmospheric forcing data are established for CLM based on newly built solarradiation and assimilated precipitation rate data respectively. The influences withdifferent atmospheric forcing to the simulated land variables of land surfacemodel are disscused and analysized. Meanwhile, a set of soil temperature and soilmoisture data is established and the distribution and evolvement of land surfacevariables (including soil temperature and soil moisture) is analysized.In brief, this thesis develops a 3DVar assimilation system for atmospheric forcingvariables of land surface model and establishes a set of relative accurate atmosphericforcing data with diurnal variation that meets the requirements of land surface model.By applying these data into CLM, a set of soil temperature and soil moisture data isgenerated, providing the basis for model validation, simulation analysis and climatechange studies.更多还原