关键陆面参数的反演和优化及其对陆气相互作用过程的改进

项目名称： 关键陆面参数的反演和优化及其对陆气相互作用过程的改进

项目编号： No.41475063

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 天文学、地球科学

项目作者： 郭维栋

作者单位： 南京大学

项目金额： 98万元

中文摘要： 陆-气相互作用是气候系统的基本过程之一，对于不同时、空尺度上的天气和气候过程具有深刻的影响。在陆面过程模式本身结构不断改进和驱动场及边界条件逐步完善的情况下，陆面参数的不确定性更加成为制约陆气相互作用模拟能力的突出因素。为此，我们首先利用能考虑参数耦合效应的方法对陆面模式中的主要参数进行敏感性分析，甄别出关键陆面参数。进而利用多个野外试验的观测数据，结合大气边界层湍流交换理论，对关键陆面参数进行反演。同时，引入条件非线性最优扰动（CNOP）方法，对不能进行反演的敏感参数做优化，减小其不确定性。在此基础上，选取陆气相互作用强烈且陆面模式模拟能力有限的半干旱区作为典型区域，将改进了关键陆面参数的陆面过程模式与区域气候模式相耦合，并对耦合模式对该地区能量水分循环及区域气候特征的模拟能力的改进程度进行评估。在更多试验数据的支持下，本研究还有望为建立符合中国陆面特征的区域气候模拟系统做出持续的贡献。

中文关键词： 陆面参数；敏感性分析；反演；优化；陆气相互作用

英文摘要： As one of the fundamental processes of climate system, land-atmosphere interaction plays key role in affecting weather and climate changes at various spatial and temporal scales. The uncertainties of parameters restrict the performance of land surface model in much degree, especially under the background of better representation of model processes, and more accurate forcing field and boundary conditions. In this proposal, we are going to adopt a new approach to analyze the sensitivity of a group of model parameters, and identify the key land surface parameters accordingly. Aiming at the key parameters, the retrieval value will be calculated based on the data from a number of field experiments together with the turbulent fluxes exchange theory within boundary layer. At the same time, a new method, Conditional Nonlinear Optimal Perturbation (CNOP) will be introduced to carry out optimization for the rest of the key parameters which are empirical and cannot be retrieved. Furthermore, to evaluate the effects of the above mentioned studies, we choose semi-arid region as a target domain where the land-atmosphere interaction is strong while the performance of land surface models is relatively poor. The evaluation will focus on the simulation of land surface fluxes, energy and water cycle, and main regional climate characteristics as well by using a land-atmosphere coupled regional model. In addition, the achievements from the project are also expected to make continuous contributions to the establishment of a regional climate modeling system which suits the regional land surface characteristics in China given the availability of broader data resources.

英文关键词： land surface parameter;sensitivity analyses;retrieval;optimization;land-atmosphere interaction