2022年长江上游流域夏季干旱气候特征及成因分析  

Climatic characteristics and cause analysis on the summer drought in the upper reaches of the Yangtze River

作　　者：高雅琦 肖莺[1] 秦鹏程[1] 熊开国 刘敏[1] GAO Yaqi;XIAO Ying;QIN Pengcheng;XIONG Kaiguo;LIU Min(Wuhan Regional Climate Center,Wuhan 430074)

机构地区：[1]武汉区域气候中心,武汉430074

出　　处：《中国防汛抗旱》2023年第3期12-17,共6页China Flood & Drought Management

基　　金：湖北省自然科学基金(2022CFD014);长江流域气象开放基金(CJLY2022Y07);国家重点研发计划(2018YFC1508002);中国长江电力股份有限公司(242102001)。

摘　　要：基于1981—2022年夏季逐日气象干旱综合指数资料,分析了长江上游夏季干旱的气候特征,利用全球再分析资料和环流指数监测资料,从Rossby波传播、西太平洋副热带高压(以下简称西太副高)和水汽输送3个方面分析了干旱期间的环流特征。结果表明:长江上游夏季干旱事件发生频率为3~4次/10 a,环流特征表现为干旱期间欧亚地区对流层中高层呈“正—负—正”的波列,异常中心分别位于欧洲北部地区,巴尔喀斯湖附近及我国大部地区。中高纬度扰动在沿西风带向东传播时,没有出现在东亚向东南方向传播的特征,造成冷空气活动位置偏北,很难影响到长江上游。副热带的西太副高偏强偏西和偏小偏东,长江上游都可能出现干旱。孟加拉湾水汽输送弱,南海水汽输送经过长江流域进入更北地区,导致长江上游处在水汽辐散区,不利于流域降水的产生。Based on the daily meteorological drought comprehensive index data in the summer of from 1981 to 2022,the study analyzed in detail the climate characteristics of summer drought in the upper reaches of the Yangtze River.Based on global reanalysis data and the circulation characteristic index, the circulation characteristics during drought are analyzed from Rossby wave propagation, West Pacific subtropical high(WPSH) and water vapor transport. The results showed that the frequency of summer drought events in the upper reaches of the Yangtze River was 3-4 times every 10years. The “ +-+ ” circulation pattern was located in the middle and upper troposphere of Eurasia during the drought period. The anomaly centers are located in northern Europe, near the Balkhas Lake and most of China. The mid-high latitude disturbance propagates eastward along the westerlies, without the characteristic of propagating southeastward in East Asia, resulting in the northward location of cold air activity, which hardly affected the upper reaches of the Yangtze River. Drought may occur when WPSH in the subtropical zone was strong to the west and small to the east, and drought may occur in the upper reaches of the Yangtze River. The water vapor transport from the Bay of Bengal was weak, and that from the South China Sea passed through the Yangtze River and influenced the northern region, resulting that the upper reaches of the Yangtze River was in divergence, which was not conducive to precipitation in the basin.

关 键 词：长江上游 气象干旱 大气环流 2022年 

分 类 号：S423[农业科学—植物保护]