集合最优插值中的样本选取  

Choice of Ensemble Members for Ensemble Optimal Interpolation

作　　者：闫长香[1] 朱江[1] 

机构地区：[1]中国科学院大气物理研究所,北京100029

出　　处：《气候与环境研究》2011年第4期452-458,共7页Climatic and Environmental Research

基　　金：中国科学院方向性项目KZCX2-YW-143;国家重点基础研究发展计划2010CB950401;国家自然科学基金资助项目40606008;40437017;40221503;40776011

摘　　要：背景误差协方差控制了分析向观测调整的幅度以及调整的结构,所以其对同化分析的质量起着至关重要的作用。对于集合同化方法而言,样本决定了背景误差协方差的分布。基于HYCOM海洋数值模式结果,针对集合最优插值方法,探讨了静态样本的选取和更新对背景误差协方差结构分布的影响,研究结果表明:由变量的原始状态数据估计的静态样本会夸大样本相关性,由扣除季节变化得到的距平数据统计出的静态样本能比较合理地反映背景误差协方差的结构;在季风控制区,具有季节变化的样本比静态样本更能适应背景误差协方差随流形分布的特征。同时一系列的同化试验也被实施来进一步调查不同样本对同化分析的影响。The back error covariance controls the magnitude and structure of adjustment to the observations.Therefore,it plays a very important role in the quality of the assimilation.For the ensemble-based data assimilation methods,the ensemble determines the distribution of the background error covariance.This study investigates the impacts of choice and update of static ensemble for Ensemble Optimal Interpolation（EnOI） on the structure of the back-error covariance based on the long-time HYCOM model integration.The result shows that the static ensemble consisting of original model states amplify the ensemble correlation.The ensemble estimated from the model anomalies obtained by subduction of seasonal signals may reflect a reasonable distribution of the back errors.In the region dominated by the monsoon,the ensemble with season changes describes the flow-dependence of back-error cova-riance better than the static ensemble.A series of experiments are carried out to validate the effects of different ensembles on the assimilation.

关 键 词：样本 集合最优插值 背景误差协方差 流依赖 

分 类 号：P73[天文地球—海洋科学] O224[理学—运筹学与控制论]