四川凉山州西南低涡型暖区暴雨的统计特征  

Statistical Characteristics of Torrential Rain in the Low Vortex Warm Region of Southwest Liangshan Prefecture in Sichuan

作　　者：边茜 李春忱 BIAN Qian;LI Chun-cheng(Liangshan Meteorological office,Liangshan Sichuan 615000,China)

机构地区：[1]四川省凉山州气象局,四川凉山615000

出　　处：《西华师范大学学报（自然科学版）》2025年第1期58-64,共7页Journal of China West Normal University(Natural Sciences)

基　　金：中国气象局创新发展专项资助项目(CXFZ2021Z014)。

摘　　要：利用凉山州近10年4—10月的降水资料、常规地面观测、高空观测、ERA5再分析资料和FY-2G卫星TBB资料,对四川省凉山州西南低涡型区域性暖区暴雨进行统计分析和天气学分析。结果表明:(1)凉山州西南低涡型暖区暴雨的发生频率在年际变化上呈波动趋势,2016年和2022年发生频率最高,2017年最低;暴雨主要发生在夏季(6—8月),其中7月发生的频率最高;暴雨具有短时强降水特征,强降水常出现在傍晚到夜间,白天降水强度减弱。(2)暴雨发生在高能高湿的不稳定层结中,其水汽主要来源于孟加拉湾。(3)影响凉山州的西南低涡主要生成于川西高原南部到凉山州西北部,少数生成于四川盆地西南部到凉山州西北部,极少数生成于攀西地区西南部,故川西高原南部是凉山州西南低涡型暖区暴雨对流云团的主要发源地。(4)西南低涡暴雨对流云团常由块状和带状混合影响,影响范围广;暴雨区常出现在低涡中心或外围东南侧,降水成片集中。Based on the precipitation data,conventional ground observation,high altitude observation,ERA5 reanalysis data and FY-2G satellite TBB data in Liangshan prefecture from April to October in the past 10 years,a statistical and a synoptic analysis of the torrential rain in the low vortex warm region of southwest Liangshan prefecture in Sichuan province were carried out.The results are as follows:(1)The occurrence frequency of torrential rain in the low vortex warm region of southwest Liangshan prefecture has fluctuated with interannual variation,with the highest frequency in 2016 and 2022 but the lowest frequency in 2017;the torrential rain mainly occurs in summer(June-August),with the highest frequency in July;the torrential rain is characterized by short-term strong precipitation,which often occurs from evening to night,and decreases during the day.(2)The torrential rain occurs in the high-energy and high-humidity unstable stratification,and its moisture mainly comes from Bay of Benga.(3)The southwest low vortexes affecting Liangshan prefecture are mainly generated in the south of Western Sichuan Plateau and the northwest of Liangshan prefecture,and only a few are generated in the southwest of Sichuan Basin and the northwest of Liangshan prefecture,and a tiny minority are generated in the southwest of Panxi region;therefore,the south of West Sichuan Plateau is the main origin of convective cloud clusters in the low vortex warm region of southwest Liangshan prefecture.(4)The convective cloud clusters of torrential rain in southwest low vortexes are often influenced by the mixture of blocky and banded pressure zones,and the influence range is wide;the heavy rain area often appears in the center of low vortex or the southeast of the periphery,and the precipitation is concentrated.

关 键 词：凉山州 西南低涡 暖区暴雨 高能高湿 对流云团 

分 类 号：P458.3[天文地球—大气科学及气象学]