2021年山东秋季降水异常偏多成因分析  

Analysis on the causes of positive precipitation anomaly in Shandong in the autumn of 2021

作　　者：徐玮平 邢雅敏 孟祥新 杨成芳[1,4] 伯忠凯 刘诗梦[5] XU Weiping;XING Yamin;MENG Xiangxin;YANG Chengfang;BO Zhongkai;LIU Shimeng(Key Laboratory for Meteorological Disaster Prevention and Mitigation of Shandong,Jinan 250031;Shandong Climate Center,Jinan 250031;Zhoucun Meteorological Bureau of Zibo in Shandong,Zibo 255400;Shandong Meteorological Observatory,Jinan 250031;Inner Mongolia Climate Center,Hohhot 010051)

机构地区：[1]山东省气象防灾减灾重点实验室,济南250031 [2]山东省气候中心,济南250031 [3]山东省淄博市周村区气象局,淄博255400 [4]山东省气象台,济南250031 [5]内蒙古自治区气候中心,呼和浩特010051

出　　处：《暴雨灾害》2023年第2期179-187,共9页Torrential Rain and Disasters

基　　金：山东省气象局科研项目(SDYBY2021-08,SDYBY2019-02,2021SDQXZ10)。

摘　　要：利用1961—2021年山东123个国家级气象观测站逐日降水资料、ERA5逐月再分析资料和NOAA海温数据,对2021年山东秋季降水异常偏多成因进行分析。结果表明,500 hPa位势高度场上中高纬地区上空存在着“两脊一槽”双阻型的环流形势,贝加尔湖以西地区长波槽加深加强,有助于西路冷空气南下东传影响山东。西太平洋副热带高压(以下简称副高)较常年面积偏大,强度偏强,脊点偏西,脊线偏北,将外围充足的暖湿气流向北输送至黄淮地区,为山东地区提供了充足的水汽。冷空气与暖湿气流交汇于黄淮地区,导致降水异常偏多。进一步分析表明,在赤道中东太平洋冷水状态和印度洋海温持续暖位相的协同影响下,导致副高偏强偏西偏北,从而为暖湿气流输送提供有利的水汽条件。副高异常偏强偏北、南美东海岸和北太平洋海温异常偏暖、赤道中太平洋海温异常偏冷是造成山东9月降水异常偏多的主要原因。Based on daily precipitation data of 123 national stations in Shandong province from 1961 to 2021,ERA5 monthly reanalysis data and NOAA sea surface temperature data,the causes of the positive precipitation anomaly in Shandong in autumn 2021 were analyzed.The results showed that there was a"two ridges and one trough"double-resistance circulation pattern over mid-high latitudes at the geopotential height of 500 hPa.The long-wave trough in the west of Lake Baikal was deepened and strengthened,which was conducive to the southward and eastward transmission of cold air from the west road to affect Shandong.The Western Pacific Subtropical High had larger area and stronger intensity than usual,with the ridge point to the west and the ridge line to the north,which transported sufficient warm and wet air from the periphery northward to the Huanghuai area and provided sufficient water vapor for Shandong.The intersection of cold air and warm and wet air flow in the Huanghuai area leaded to abnormally more precipitation.Further analysis showed that under the synergistic influence of the cold water state in the equatorial Middle Eastern Pacific and the warm sea surface temperature phase in the Indian Ocean,the Western Pacific Subtropical High was stronger,more westerly and northerly,thus providing favorable water vapor conditions for the transport of warm and wet air.The stronger and northerly Western Pacific Subtropical High anomaly,the warm SST anomaly over the east coast of South America and the north Pacific Ocean,and the cold SST anomaly over the central equatorial Pacific Ocean were the main reasons for the positive precipitation anomaly in Shandong in September of 2021.

关 键 词：山东秋雨 副高 大气环流 海温异常 

分 类 号：P467[天文地球—大气科学及气象学]