云南雨季开始期时空变化特征及其与ENSO的关系  

Spatial and Temporal Characteristics of the Onset Date of Rainy Season in Yunnan and Its Relationship with ENSO

作　　者：陈艳[1] 郭世昌[2] 刘瑜[3] 琚建华[1] 任菊章[1] 张惠珠[2] 

机构地区：[1]云南省气象科学研究所,云南昆明650034 [2]云南大学资源环境与地球科学学院大气科学系,云南昆明650091 [3]云南省气候中心,云南昆明650034

出　　处：《干旱气象》2017年第4期545-551,共7页Journal of Arid Meteorology

基　　金：国家自然科学基金(41365007;41565002;41665005)资助

摘　　要：利用1971—2015年云南省124个气象台站雨季开始日期、美国NCEP/NCAR再分析资料和CPC热带太平洋海温指数等数据,运用数理统计方法分析了云南雨季开始期的时空变化特征及其与前期热带太平洋海温的关系。结果表明:(1)云南雨季主要从东、南、西3个方向呈半包围态势向西北腹地推进,具有明显的季风交汇区特征;(2)前期热带太平洋海温对云南雨季开始期的第一空间分布模态(全区一致型)影响显著,即除了雨季开始最早的滇西北、滇西、滇东北和滇东南等少数边缘地区,云南大部分区域的雨季开始期与热带太平洋海温存在显著的正相关关系,其中与前期3—4月Ni1o3.4指数相关性最好;(3)云南雨季开始期对前期3—4月Ni1o3.4指数的响应具有非对称性,对暖事件的响应大于对冷事件的响应;(4)前期热带太平洋海温主要通过影响低纬Walker环流和季风系统进而影响云南雨季的开始。Based on the onset date of rainy season at 124 weather stations of Yunnan Province,NCEP/NCAR reanalysis data,the tropical Pacific sea surface temperature（SST） index from CPC and OLR from NOAA during 1971-2015,the spatial and temporal characteristics of the onset date of Yunnan＇s rainy season（ODYRS） and its relationship with tropical Pacific SST were investigated by using statistical methods such as correlation analysis,EOF analysis and composite analysis,etc. The results are as follows：（1） ODYRS marched from the south,east and west to the inner of northwestern Yunnan Province,and the intersection characteristic of Asian summer monsoon systems for ODYRS was obvious. The marching from the south to the north was closely related to the advancement of Asian tropical summer monsoon,while that of other two directions were probably influenced by subtropical systems.（2） The influence of preceding tropical Pacific SST on the first spatial mode of ODYRS was significant. In other words,ODYRS in most regions of Yunnan were significantly positive correlation with tropical Pacific SST,especially the Ni1o3. 4 index in preceding March and April,except for a few edge areas in the northwest,west,northeast and southeast of Yunnan.（3） The response of ODYRS to the preceding Ni1o3. 4 index was asymmetric,and the response to the warm events was stronger than the cold events.（4） The preceding tropical Pacific SST could influence Walker circulation and monsoon systems in low latitude,and then affect ODTRS.

关 键 词：季风交汇区 云南雨季开始期 热带太平洋海温 

分 类 号：P461.2[天文地球—大气科学及气象学]