基于HYSPLIT模式的凉山“8.21”致洪暴雨水汽特征分析  

Analysis of Water Vapor Characteristics of"8.21"Flood-causing Rainstorm in Liangshan Based on HYSPLIT Model

作　　者：边茜 李春忱 唐毓羚 刘小欧 BIAN Qian;LI Chunchen;TANG Yuling;LIU Xiaoou(Liangshan Meteorological Service,Xichang 615000,China;Yanyuan County Meteorological Service,Yanyuan 615701,China)

机构地区：[1]四川省凉山州气象局,西昌615000 [2]四川省盐源县气象局,盐源615701

出　　处：《高原山地气象研究》2024年第S01期52-58,共7页Plateau and Mountain Meteorology Research

基　　金：凉山州气象局科研项目(202307)。

摘　　要：利用常规地面、高空气象观测资料、NCEP再分析资料和GDAS资料,结合HYSPLIT模式对凉山州2023年8月21日致洪暴雨天气过程的环流形势和水汽特征进行分析。结果表明:短波槽、切变线、地面冷空气及强烈的不稳定能量是此次暴雨产生的有利条件。运用HYSPLIT模式追踪发现,700 hPa水汽主要来源于东南气流,600 hPa水汽主要来源于西南或偏南气流,500 hPa水汽主要来源于北方,从而形成“上冷下暖”的不稳定层结,有利于触发对流天气。进一步对追踪结果做聚类分析发现,影响此次暴雨天气的中低层(700~600 hPa)水汽主要来源于凉山州及周边地区,其次是孟加拉湾及周边地区,两者的水汽贡献率之和高达90%以上。500 hPa水汽主要来源于孟加拉湾及周边地区和青藏高原东侧,两者的水汽贡献率占79%。凉山及周边地区水汽在暴雨过程中的贡献越往低层越高。暴雨发生过程中,低层均存在MPV1<0、MPV2>0的配置,且MPV1<0、MPV2>0的区域与暴雨区有很好的对应关系。Using the conventional surface and upper-air meteorological observation data,NCEP reanalysis data and GDAS data,combined with HYSPLIT model,the circulation situation and water vapor characteristics of the flood-causing rainstorm weather process on August 21,2023 in Liangshan Prefecture were analyzed.The results show that short-wave trough,shear line,surface cold air and strong unstable energy were the favorable conditions for the rainstorm.The water vapor at 700 hPa mainly came from the southeast airflow,the water vapor at 600 hPa mainly came from the southwest or southerly airflow,and the water vapor at 500 hPa mainly came from the north,thus forming an unstable stratification of“upper cold and lower warm”,which was conducive to triggering convective weather.With HYSPLIT model,the further cluster analysis of the tracking results showed the water vapor in the middle and lower levels(700~600 hPa)mainly came from the local area of Liangshan Prefecture and its surrounding areas,followed by Bay of Bengal and its surrounding countries,the water vapor contribution rate of the two was more than 90%.The water vapor at 500 hPa mainly came from Bay of Bengal and its surrounding countries and the eastern side of the Tibetan Plateau,the contribution rate of water vapor was 79%.The contribution of water vapor to the rainstorm process in Liangshan and its surrounding areas was higher at the lower level.The MPV showed that there were configurations of MPV1<0 and MPV2>0 in the lower layer during the process of heavy rain,and the regions of MPV1<0 and MPV2>0 were in good correspondence with the heavy rain area.

关 键 词：暴雨 水汽特征 HYSPLIT模式 水汽贡献 

分 类 号：P458.3[天文地球—大气科学及气象学] P426