North Atlantic forcing of autumn drought in Southwest China  

作　　者：Chaoxia Yuan Wei Zhang Yahan Zhong Xinyu Lu Jingchan Liu Md Wahiduzzaman 

机构地区：[1]Key Laboratory of Meteorological Disaster of Ministry of Education,Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Institute for Climate and Application Research(ICAR),Nanjing University of Information Science and Technology,Nanjing,China [2]Yunnan Institute of Meteorological Sciences,Kunming,China

出　　处：《Atmospheric and Oceanic Science Letters》2022年第1期76-80,共5页大气和海洋科学快报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (NSFC) [grant numbers 42088101 and 41875099]。

摘　　要：Drought often lasts long and is thus closely related to slowly varying external forcing such as sea surface temperature(SST).Here,based on observed precipitation and SST data along with NCEP-DOE reanalysis data,the possible impacts of North Atlantic SST on drought formation in Southwest China are investigated.Results show that northeast-southwest-orientated dipole SST anomalies in the mid-high latitudes of the North Atlantic are closely related to autumn drought in Southwest China;the linear correlation coefficient between them reaches 0.48 during 1979-2020,significant at the 0.001 level.The dipole SST anomalies trigger southeastward-propagating Rossby waves and induce barotropic cyclonic circulation anomalies over India and the western Tibetan Plateau.This enhances the upward motion in northern India and the western Tibetan Plateau and causes a compensating downdraft,reduced precipitation,and consequent drought formation in Southwest China.干旱持续时间长,因此往往和缓慢变化的海温异常相关.本文利用观测降水和NCEP-DOE再分析资料,探讨了北大西洋中高纬地区东北-西南走向的偶极子海温异常对我国西南地区秋季干旱的影响.结果显示该偶极子海温异常可激发向东南方向传播的Rossby波,在印度北部和青藏高原西部引起正压气旋性环流和上升运动异常,并在我国西南地区引起补偿性下沉运动,导致降水减少,引发干旱.

关 键 词：Autumn drought Southwest China North Atlantic SST TELECONNECTION 

分 类 号：P426.616[天文地球—大气科学及气象学] P731.11