基于经验正交函数和奇异值分解对东亚季风区跨季度夏季降水距平的订正方法

基于经验正交函数(EOF)和奇异值分解(SVD)方法,作者对IAP9L-AGCM后报的东亚季风区1984～2003年共20年的跨季度夏季降水距平场进行回归订正,并对订正前后降水距平场与实测场间的空间相似性、强度、以及年际变化相关性进行分析.结果表明这两种订正方案均能明显提高夏季降水距平预报场与实测场间的空间相似性和年际变化相关性;而基于EOF的订正方案对强度的订正效果要优于基于SVD的订正方案.此外,在此基础上,我们进一步提出多种订正方法集合的思想.

The Methods for Correcting the Summer Precipitation Anomaly Predicted Extraseasonally over East Asian Monsoon Region Based on EOF and SVD

Two correction methods based on Empirical Orthogonal Function(EOF) and Singular Value Decomposition(SVD) are used to verify the summer-mean precipitation anomaly over East Asian monsoon region.The extraseasonal predictions,which are forced by the observed sea surface temperature anomalies,are 20 years from 1984 to 2003 by using IAP 9L-AGCM.The pattern correlation,intensity,and the correlation of interannual variability between the corrected precipitation anomalies and the observed are compared,and the results show the pattern correlation in most years and correlation of interannual variability are significantly enhanced for both SVD-based and EOF-based methods,the intensity corrected by the EOF-based method is better than that by SVD-based method.Moreover,some ideas about the ensemble correction methods are proposed.