东亚夏季风爆发和北进的年际变化特征及其与热带西太平洋热状态的关系  

Characteristics of the Interannual Variations of Onset and Advance of the East Asian Summer Monsoon and Their Associations with Thermal States of the Tropical Western Pacific

作　　者：黄荣辉[1] 顾雷[1] 徐予红[1] 张启龙[2] 吴尚森[3] 曹杰[4] 

机构地区：[1]中国科学院大气物理研究所,北京100080 [2]中国科学院海洋研究所,青岛266071 [3]中国气象局广州热带海洋气象研究所,广州510080 [4]云南大学大气科学系,昆明650091

出　　处：《大气科学》2005年第1期20-36,共17页Chinese Journal of Atmospheric Sciences

基　　金：国家自然科学基金重点项目 40 2 31 0 0 5;中国科学院知识创新工程重要方向项目KZCX3 SW 2 1 8

摘　　要：利用我国测站的降水资料、卫星测得的OLR和高云量资料、SST和 137°E次表层海温资料以及NCEP NCAR再分析资料 ,分析了东亚夏季风的爆发和北进的年际变化特征及其与热带西太平洋热状态的关系。分析结果表明 :当春季热带西太平洋处于暖状态 ,菲律宾周围对流活动强 ,在这种情况下 ,南海上空对流层下层有气旋性距平环流 ,西太平洋副热带高压偏东 ,从而使得南海夏季风爆发早 ;并且 ,当夏季热带西太平洋也处于暖状态 ,菲律宾周围对流活动也很强 ,在这种情况下 ,西太平洋副热带高压北进时 ,在 6月中旬和 7月初存在明显的突跳 ,从而使得东亚季风雨带在 6月中旬明显由华南北跳到江淮流域 ,并于 7月初由江淮流域北跳到黄河流域、华北和东北地区。这将引起江淮流域和长江中、下游夏季风降水偏少 ,并往往发生干旱 ,而黄河流域、华北和东北地区的夏季降水正常或偏多。相反 ,当春季热带西太平洋处于冷状态 ,菲律宾周围对流活动弱 ,在这种情况下 ,南海上空对流层下层有反气旋性距平环流 ,西太平洋副热带高压偏西 ,从而使得南海夏季风爆发晚 ;并且 ,当夏季热带西太平洋也处于冷状态 ,菲律宾周围对流活动也很弱 ,在这种情况下 ,西太平洋副热带高压北进时 ,在 6月中旬或 7月初向北突跳并不明显 ,而是以渐进式向北移动 ,从?Characteristics of the interannual variations of onset and advance of the East Asian summer monsoon and their associations with thermal states of the tropical western Pacific are analyzed by using the precipitation data at observational stations of China, data of OLR and high cloud amount observed by satellite, data set of SST and ST in subsurface of the western Pacific along 137°E and the NCEP/NCAR reanalysis data. The results show that when the tropical western Pacific is in a warming state in spring, convective activities are intensified around the Philippines. In this case, there is a cyclonic anomaly circulation in the lower troposphere over the South China Sea, and the western Pacific subtropical high shifts eastward, thus, the early onset of the South China Sea summer monsoon (SCSM) can be caused. Moreover, when the tropical western Pacific is also in a warming state, convective activities around the Philippines are also strong in summer, since the western Pacific subtropical high abruptly shifts northward in mid-June and early July during its northward advance in this case, the abrupt northward-shift of the East Asian summer monsoon rainband from South China to the Yangtze River and the Huaihe River valleys is obvious in mid-June and this monsoon rainband again jumps northward from the Yangtze River and the Huaihe River valleys to the Yellow River valley, North China and Northeast China in early July. This can cause that summer monsoon rainfall is below normal and drought may occur in the Yangtze River and the Huaihe River valleys and the middle and lower reaches of the Yangtze River, but summer rainfall is normal or above normal in the Yellow River valley, North China and Northeast China. On the other hand, when the tropical western Pacific is in a cooling state in spring, convective activities are weakened around the Philippines. In this case, there is an anticyclonic anomaly circulation in the lower troposphere over the South China Sea, and the western Pacific subtropical high shifts westward, thus, t

关 键 词：热带西太平洋 西太平洋副热带高压 对流活动 东亚夏季风 年际变化 江淮流域 南海夏季风 春季 干旱 黄河流域 

分 类 号：P732[天文地球—海洋科学] P425.42