亚洲夏季风对江淮梅雨入梅早晚的影响  

The influence of Asian summer monsoon synergy on the Meiyu onset date in the region of Yangtze-Huaihe basin in China

作　　者：陈笑笑 黄治勇[1,2] 姚瑶 汤兴芝[1] 鞠英芹[1] 顾永刚 李留毅 CHEN Xiaoxiao;HUANG Zhiyong;YAO Yao;TANG Xingzhi;JU Yingqin;GU Yonggang;LI Liuyi(Hubei Branch of China Meteorological Administration Training Center,Wuhan 430074;Hubei Key Laboratory for Heavy Rain Monitoring and Warning Research,Wuhan 430205)

机构地区：[1]中国气象局气象干部培训学院湖北分院,武汉430074 [2]中国气象局武汉暴雨研究所暴雨监测预警湖北省重点实验室,武汉430205

出　　处：《暴雨灾害》2023年第5期563-571,共9页Torrential Rain and Disasters

基　　金：国家自然科学基金项目(41971026);湖北省气象局青年科技发展基金项目(2022Q14);干部学院科技发展基金项目(2023CMATCQN13)。

摘　　要：入梅时间早晚直接影响梅雨期雨量的多寡,其准确预测对农业、交通和旅游业等气象服务具有重要意义。利用中国气象局2017年发布的《梅雨监测业务规定》中的入梅日期资料和NCEP/NCAR再分析资料,研究1981—2020年江淮梅雨入梅早晚的气候特征,分析亚洲夏季风对入梅日早晚的影响。结果表明:(1)江淮梅雨入梅日具有显著的年际变化特征,平均入梅日为6月21日,标准差为11 d,最早和最晚入梅日相差39 d。(2)入梅日与南亚夏季风SASM(South Asian Summer Monsoon)呈显著负相关,与东亚夏季风EASM(East Asian Summer Monsoon)呈正相关。强SASM年,南亚高压偏东,中高纬度高空急流偏南,江淮地区为水汽辐合区,有利于江淮区入梅偏早;强EASM年,西太副高偏北偏强,南风气流旺盛,水汽在华南和东北地区辐合,在江淮地区辐散,不利于梅雨的发生。(3)由于亚洲夏季风具有协同爆发的特点,强SASM-弱EASM协同年,平均入梅日较常年平均偏早4 d,与之相反的协同年入梅日偏晚11.6 d。强SASM-弱EASM年,江淮地区位于高空急流出口右侧,伊朗高压位置偏东,高空受小槽东移影响,低层南亚夏季风发展旺盛,水汽在江淮地区辐合,有利于入梅偏早。弱SASM-强EASM年,中高纬度高空急流轴偏北,江淮地区受脊前偏北气流控制,低层亚洲夏季风辐合区偏东,江淮地区仅为过路水汽通道,不利于江淮区入梅。故亚洲夏季风的强弱与协同发展对江淮梅雨入梅早晚具有一定的指示意义。The time of Meiyu onset directly affects the amount of rainfall during Meiyu period,and its accurate prediction is of great signifi⁃cance to meteorological services such as agriculture,transportation and tourism.In this paper,the date of Meiyu onset by China Meteorologi⁃cal Administration in 2017 and NCEP/NCAR reanalysis data are used,the climatic characteristics of the beginning of the rainy season and the influence of Asian summer monsoon on the Meiyu onset are analyzed in the region of Yangtze-Huaihe basin from 1981—2020.The re⁃sults show that:(1)The Meiyu onset date in the region of Yangtze-Huaihe basin has obvious interannual variation characteristics.The aver⁃age time of Meiyu onset in the region of Yangtze-Huaihe basin is June 21,the standard deviation is 11 days,with a difference of 39 days be⁃tween the earliest and latest Meiyu onset.(2)The Meiyu onset date is significantly negatively correlated with the South Asian summer mon⁃soon(SASM)and positively correlated with the East Asian summer monsoon(EASM).In strong SASM years,the South Asian high is east⁃ward,mid-high latitude upper jet stream is southward,and the region of Yangtze-Huaihe basin is water vapor convergence areas,which is conducive to the early start of Meiyu.In strong EASM years,the subtropical high in the Western Pacific is stronger northward,the southerly airflow is strong,the water vapor converged in South China and Northeast China,and divergent in the region of Yangtze-Huaihe basin,which is not conducive to the generation of Meiyu.(3)Since the Asian summer monsoon has the characteristics of co-occurrence,in the strong SASM-weak EASM year,the average Meiyu onset date is 4 days earlier,and in the opposite co-occurrence year,the Meiyu onset date is 11.6 days later.In strong SASM-weak EASM years,the Meiyu area is located on the right side of the upper jet exit,the Iran high is located to the east,and the upper air is affected by the eastward movement of the small trough.The low-level South Asian summer monsoon is develop⁃ing

关 键 词：南亚夏季风 东亚夏季风 协同作用 江淮梅雨 

分 类 号：P466[天文地球—大气科学及气象学]