华西南区秋雨异常及其对青藏高原冬季大气冷源的响应  

Anomaly of Autumn Rain in the South Area of West China and Its Response to Atmospheric Cold Sources over the Tibetan Plateau in Winter

作　　者：郑然[1,2] 刘嘉慧敏 王春学[1,2] 李栋梁 唐红玉[5] 刘博[6] ZHENG Ran;LIU Jiahuimin;WANG Chunxue;LI Dongliang;TANG Hongyu;LIU Bo(Sichuan Provincial Climate Center,Chengdu 610072,China;Institute of Plateau Meteorology,China Meteorological Administration,Heavy Rain and Drought-Flood Disasters in Plateau and Basin Key Laboratory of Sichuan Province,Chengdu 610072,China;Shaanxi Provincial Meteorological Observatory,Xi’an 710014,China;Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Science&Technology,Nanjing 210044,China;Chongqing Climate Center,Chongqing 401147,China;Unit 78092 of the PLA,Chengdu 610036,China)

机构地区：[1]四川省气候中心,四川成都610072 [2]中国气象局成都高原气象研究所,高原与盆地暴雨旱涝灾害四川省重点实验室,四川成都610072 [3]陕西省气象台,陕西西安710014 [4]南京信息工程大学气象灾害预报预警与评估协同创新中心,江苏南京210044 [5]重庆市气候中心,重庆401147 [6]中国人民解放军78092部队,四川成都610036

出　　处：《干旱气象》2021年第2期225-234,共10页Journal of Arid Meteorology

基　　金：四川省重点实验室科技发展基金项目(2018-青年-05);中国气象局预报员专项(CMAYBY2020-130);中国气象局核心业务发展专项[YBGJXM(2019)0606];国家自然科学基金项目(41275097)共同资助。

摘　　要：利用1971—2017年华西秋雨南区269个气象站逐日降水资料和NCEP/NCAR再分析资料等,分析华西南区秋雨强度变化及其大气环流异常特征,寻找影响华西南区秋雨强度的大气冷源关键区,并就关键区大气冷源对南区秋雨强度的影响进行诊断。结果表明:华西南区秋雨强度整体变化趋势不显著,其年际变化可能受前期冬季(1月)青藏高原大气冷源异常变化的滞后影响。当前期冬季高原冷源偏强(弱)时,可激发南海到西太平洋一带气旋(反气旋)性异常环流并持续到夏季,其南侧持续偏西(东)气流使得赤道西(中)太平洋地区表层暖水东(西)传,造成赤道中太平洋地区海温暖(冷)异常,继而在其西北侧西太平洋地区激发气旋(反气旋)性环流,华西地区处于该环流西侧的偏北(南)风控制下,水汽条件较差(好),降水偏少(多),华西南区秋雨偏弱(强)。Based on the daily precipitation data of 269 meteorological observation stations in the south area of West China from 1971 to 2017 and the NCEP/NCAR reanalysis data,etc.,the change of autumn rain intensity and the characteristics of corresponding atmospheric circulation anomalies in the south area of West China were analyzed,the key area of atmospheric cold source over the Tibetan Plateau affecting autumn rain was sought,and the influences of atmospheric cold source in the key area on autumn rain intensity in the south area of West China were diagnosed.The results show that the intensity of autumn rain in the south area of West China hadn’t a significant change trend as a whole,and its interannual change might be affected by the hysteresis of anomalous changes of atmospheric cold source over the Tibetan Plateau in previous winter(January).When the atmospheric cold source over the Tibetan Plateau was abnormally strong(weak)in previous winter,it could stimulate the cyclonic(anti-cyclonic)anomalous circulation from the South China Sea to the western Pacific and maintain until summer.The continuous westward(eastward)airflow on the south side of the cyclone(anti-cyclone)caused surface warm water over the western(central)Pacific to travel eastward(westward),which caused anomalous warm(cold)of sea temperature in the equatorial central Pacific,then stimulate a cyclonic(anti-cyclonic)circulation in the western Pacific region.The water vapor conditions were poor(good)in the south area of West China under the control of northerly(southerly)winds in the west side of the cyclone(anti-cyclone),the precipitation was less(more),and autumn rain was weak(strong).

关 键 词：华西南区 秋雨 青藏高原 大气冷源 

分 类 号：P434[天文地球—大气科学及气象学]