ENSO对华东地区春季降水影响的不对称性  

Asymmetric effect of ENSO on the spring precipitation over East China

作　　者：巩婷 易笑园[2] GONG Ting;YI Xiaoyuan(Tianjin Air Traffic Management Bureau,Civil Aviation Administration of China,Tianjin 300399,China;Tianjin Meteorological Bureau,Tianjin 300074,China)

机构地区：[1]中国民用航空华北地区空中交通管理局天津分局,天津300399 [2]天津市气象局,天津300074

出　　处：《海洋气象学报》2023年第4期40-46,共7页Journal of Marine Meteorology

基　　金：国家自然科学基金项目(41575049)。

摘　　要：利用1958-2019年的观测和再分析数据集,对冷、暖两类厄尔尼诺-南方涛动(El Ni1o-Southern Oscillation, ENSO)事件与后期华东地区春季降水之间的关系进行了分析。结果表明:(1)在暖ENSO事件中,华东春季降水量与前冬季ENSO海面温度异常存在较强的正相关关系。在冷ENSO事件中,这种强正相关向内陆地区西移,主要集中在江西和湖南。(2)暖ENSO事件通常会导致浙江、江苏和福建等沿海省份春季降水量过剩,而冷ENSO事件往往导致江西和湖南降水偏少。这归因于ENSO对大气环流的非线性影响。(3)与暖ENSO事件相比,冷ENSO事件引起的海面温度异常中心明显西移,造成异常低层大气环流的西移,最终导致华东降水的西移效应。(4)通过分析和发现,强调了华东春季降水对ENSO的非线性响应,这对华东地区的季节性气候预测具有重要意义。Using the observations and reanalysis datasets from 1958 to 2019,this study reveals an asymmetric effect of El Ni1o-Southern Oscillation(ENSO)on the following spring precipitation over East China.The results are listed as below.(1)During the years with positive ENSO phases,a strong positive correlation exists between the spring precipitation over Zhejiang and Jiangsu provinces and the preceding winter ENSO sea surface temperature(SST)anomalies.During the years with negative ENSO phases,such a strong positive correlation shifts westwards to inland areas,mainly in Jiangxi and Hunan provinces.(2)To be specific,the El Ni o events usually result in a precipitation surplus in the decaying spring over Zhejiang,Jiangsu,and Fujian provinces,while the La Ni a events usually lead to a precipitation deficit in the decaying spring over Jiangxi and Hunan provinces.This is attributed to the nonlinear effects of ENSO on the atmospheric circulation.(3)Compared with El Ni o,the abnormal center of SST anomalies induced by La Ni a evidently extends westwards,inducing a westward movement of the anomalous low-level atmospheric circulation,which eventually results in a westward-shifted effect on the following spring precipitation over East China.(4)The findings emphasize the nonlinear responses of the spring precipitation over East China to ENSO,which has important implications for the seasonal climate predictions over East China.

关 键 词：春季降水 华东地区 厄尔尼诺 大气环流 

分 类 号：P461.2[天文地球—大气科学及气象学]