江淮流域旱涝与大气遥相关经向波列路径特征的相关关系

THE RELATIONSHIP BETWEEN THE DROUGHT AND EXCESSIVE RAIN IN JIANG-HUAI VALLEY AND THE FEATURES OF THE MERIDIONAL WAVE TRAIN PATH

本文研究了江淮流域旱涝的影响系统及其演变特征,揭示了江淮流域旱涝前期的环流异常及遥相关现象。本文提出了江淮流域旱涝与北半球遥相关经向波列路径、位相有内在联系,即江淮降水前期遥相关波主要表现为EU(欧亚型)、PNA(太平洋北美型)两种类型的交替增强现象。另外,江淮梅期各阶段(6～8月)关键影响系统相关程度的变化亦反映出EU与PNA型遥相关波列各自增强与衰弱的过程,且江淮流域降水与同期北半球500hPa高度场各阶段相关特征可较清晰地描述出梅雨期不同阶段关键环流系统相互配置的变化关系及其中高纬冷、暖空气的活动规律的图象。

In this paper, the influence system and its evolution features of the draught and excessive rain in Jiang-Huai vally is studied, the circulation anomaly and teleconnection phenomenon of the early days of the drought and excessive rain in Jiang-Huai valley is revealed. It is put forward in this paper that there are the internal relations between the drought and excessive rain in Jiang-Huai valley and the meridional wave path and phase of the northern hemisphere teleconnection that is, the te leconnec't'ion waves of the early days of Jiang-Huai precipitation display mainly the alternately enhanced phenomenon between Eurasian(EU) pattorn and Pacific and Norfh American(PNA) pattern. In addition, the coherenced varia-tions of the key effect system during various stages (6-8) of Mei-Yu period in Jiang-Huai reflect also the respectively enhanced and collapsed process of the teleconnection wave train of EU and PNA pattern, and the various stages' corre-la'tion characteristics between the precipitation in Jiang-Huai valley and the corresponding period 500hPa geopotential height field of the northern hemisphere can describe much clearly the mutual disposition's varied relation of the key circulation system of different stages during Mei-Yu and the behaviours of the cold and warm air at middle and high latitudes.