四维EOF分析检验数值模式模拟气候及其变化能力研究  

TESTING THE ABILITY OF NUMERICAL MODEL TO SIMULATE CLIMATE AND ITS CHANGE WITH 4D EOF ANALYSIS

作　　者：赵得明[1] 苏炳凯[1] 汤剑平[1] 

机构地区：[1]南京大学大气科学系,南京210093

出　　处：《气象学报》2006年第4期420-431,共12页Acta Meteorologica Sinica

基　　金："973"国家重点基础研究发展规划项目(2001CB309400;G1999043400)

摘　　要：文章提出了一个四维经验正交函数(4D-EOF)方法,原理是三维经验正交函数(3D-EOF)与扩展经验正交函数(EEOF)简单的组合,此方法不仅提供空间水平分布特征场及其对应的月际变化特征和年际变化特征,而且还提供空间垂直结构特征。利用这个新方法分析东亚季风国际区域模式比较计划(RMIP)MM5V3模拟的1989—1998年10a积分结果———包括中国大部分区域(4941个格点,格距60km)月平均100,500,700,1000hPa4个位势高度场(模拟场)及其距平场;同时分析对应的NCAR/NCEP再分析资料(观测场),进而对比两者检验模式模拟东亚季风气候及其变化能力。对比分析结果表明:对于月平均高度场的第一特征向量场,模式能比较准确地模拟出平均气候场的分布及其垂直相当正压性的结构特征;对于月平均高度距平场第一、二特征向量场,模式对于距平场的模拟也较成功,垂直方向有明显的相当正压性特征;月平均高度场及其距平场相应的月际变化和年际变化特征也在模拟中得到较好的反映。本研究表明:4D-EOF具有综合检验数值模式模拟气候及其变化的能力,而MM5V3模拟20世纪90年代东亚气候及其变化能力是令人满意的。The four-dimensional empirical orthogonal function （4D-EOF） which in reality is a simple combination of three-dimensional EOF （3D EOF） and extended EOF（EEOF）, is put forward in this paper to test the ability of numerical model to simulate climate and its change. The 4D-EOF analysis is able to reveal not only the horizontal characteristic pattern of analysis variable, and its corresponding annual and inter-annual variations, but also the vertical structural characteristics. The method suggested is then used to analyze the monthly mean 100, 500, 700, and 1000 hPa geopotential height fields （4941 grids, grid spacing 60 km） and their anomaly fields in 1989 - 1998 simulated by the MM5V3 from the RMIP （Regional Climate Model Inter-comparison Project for East Asia） Ⅱ, as well as their counterparts （used as the observed fields） from the NCEP/NCAR re-analysis dataset in the same period. The ability of MM5V3 in simulating East Asian climate and its change is tested by comparing the 4D-EOF analysis results of the simulated and observed datasets. The comparative analyses results show that the horizontal pattern of the first eigenvector of the observed monthly mean geopotential height fields and its vertical equivalent barotropic feature were well simulated; the simulations of the first two eigenvectors of the observed monthly mean geopotential height anomaly fields were also successful for their horizontal abnormal distributions and significant equivalent barotropic features in the vertical were well reproduced; and furthermore, the observed characteristics, such as the variation with height, and annual and inter - annual variations of the monthly mean geopotential height/anomaly fields also were well reflected in the simulation. Therefore, the 4D- EOF is able to comprehensively test numerical model＇s ability of simulating the climate and its change, and the simulation ability of MM5V3 for the climate and its change in East Asia in the 1990s was satisfactory.

关 键 词：4D-EOF 数值模式 模拟能力 气候变化 

分 类 号：P532[天文地球—古生物学与地层学]