新标准下梅雨特征量的时间演变及异常梅年环流特征的分析

The Analysis of Temporal Evolution and Anomalous Circulation Characteristics of Meiyu under the New Standard

摘要: 根据中国气象局预报与网络司2014年印发的《梅雨监测业务规定》涉及的梅雨监测区梅雨划分标准、1961~2010年梅雨监测区85个站点逐日降水资料以及美国NCEP/NCAR提供的逐日再分析资料，得出了我国梅雨监测区1961~2010年50年的梅雨期入、出梅日期，以及梅雨期长度、梅雨量、梅雨强度等梅雨特征量。并分析了异常梅年的环流特征，结果如下：1) 总体来看，出梅日和梅雨量、梅雨期长度以及梅雨强度的相关性比入梅日和它们的相关性要好。2) M-K突变检验显示，梅雨监测区入、出梅日、梅雨期长度以及梅雨强度均没有发生突变。3) 在平均早入梅日前后，早入梅年，西太平洋副高较为强大，位置偏西北，副高脊线超过20˚N；晚入梅年，西太平洋副高面积明显减小，位置明显偏东。在平均晚出梅日前后，早出梅年，西太平洋副高位置偏北，西太副高脊线超过30˚N；晚出梅年，西太平洋副高依旧强大，西段副高脊线在30˚N附近。

Abstract: According to the new criterion for Rules of Meiyu Monitor, which published by The Prediction and Network Ministry of China Meteorological Administration in 2014, the daily precipitation data of Meiyu Monitor at 85 stations and daily reanalysis data of NCEP/NCAR during 1961-2010, the onsets, withdrawals, length, rainfall, and intensity of Meiyu were calculated. The results indicate that 1) the relationship between withdrawals and other features of Meiyu is closer than the relationship between onsets of Meiyu and them. 2) The M-K mutation test shows that there was no mutation in onsets, withdrawals, the length and the intensity of Meiyu. 3) Before and after mean earlier onsets, on earlier onsets year of Meiyu, Western Pacific subtropical high is strong, northwest, Western Pacific subtropical high ridge is beyond 20˚N, on late onsets year of Meiyu, Western Pacific subtropical high is weak. Before and after mean late withdrawals, on earlier withdrawals year of Meiyu, Western Pacific subtropical high ridge is beyond 30˚N, on late withdrawals year of Meiyu, Western Pacific subtropical high is strong, the west part of Western Pacific subtropical high ridge is near 30˚N.