1991—2020年暖季河套灌区强对流天气主要流型及环境参量特征分析  

Characteristics of Major Flow Patterns and Environmental Parameters of Strong Convective Weather in the Hetao Irrigation Area from 1991 to 2020

作　　者：张玉荣[1] 姚晓娟 白舜耀 赵明明 ZHANG Yurong;YAO Xiaojuan;BAI Shunyao;ZHAO Mingming(Bayannur Meteorological Bureau,Linhe 015000,China;Inner Mongolia Autonomous Region Meteorological Bureau,Huhhot 010000,China)

机构地区：[1]巴彦淖尔市气象局,内蒙古临河015000 [2]内蒙古自治区气象局,内蒙古呼和浩特010000

出　　处：《沙漠与绿洲气象》2024年第2期76-82,共7页Desert and Oasis Meteorology

基　　金：内蒙古自治区气象局科技创新项目(nmqxkjcx202313)。

摘　　要：利用常规气象观测资料、区域自动站观测资料及ERA5再分析资料,对河套灌区1991—2020年542个冰雹个例和281个短时强降水个例主要流型及环境参量特征进行分析。结果显示:(1)短时强降水天气主要有新疆低槽(涡)、东北冷涡、蒙古冷涡、西南气流4类影响系统,冰雹天气主要有蒙古冷涡、西北气流、东北冷涡、巴尔喀什湖冷涡4类影响系统;(2)河套灌区短时强降水和冰雹各关键参数预报阈值均有差异,最低阈值的建议值采用箱线图25%百分位值,其中△T_(850-500)分别为26和33℃,K指数均值分别为27和35℃,CAPE均值分别为515和405 J·kg^(-1),0~6 km垂直风切变均为7×10^(-3)s^(-1),0℃层高度均值分别为4656和4069 m,-20℃层高度均值分别为8070和7054 m;(3)冰雹需要更大的K指数、△T_(850-500)以及更强的低层暖空气,同时冰雹有更低的0℃层和-20℃层高度,较低的0℃层高度可以防止冰雹下落过程融化。此外,下垫面因子对不同强对流天气的影响程度也不同,海拔高度是影响河套灌区冰雹分布的主要因素。This paper analyzed the primary flow patterns and environmental parameter characteristics of 542 hail cases and 281 short-term heavy precipitation cases in the Hetao Irrigation Area from 1991 to 2020,using conventional meteorological observation data,regional automatic station observation data,and ERA5 reanalysis data.The results showed that:(1)The weather associated with short-term heavy precipitation is primarily characterized by four types of influencing systems,Xinjiang low trough(vortex),northeast cold vortex,Mongolia cold vortex,and southwest airflow.In contrast,hail weather is primarily associated with four types:Mongolia cold vortex,northwest airflow,northeast cold vortex,and Balkhash Lake cold vortex.(2)Variations exist in the forecasting thresholds for key parameters of short-term heavy precipitation and hailstorms in the Hetao Irrigation Area.The suggested lowest thresholds are determined based on the 25th percentile values from box-and-line diagrams.The mean values of △T_(850-500) are 26 and 33℃,the mean values of the K-index are 27 and 35℃,the mean values of CAPE are 515 and 405 J·kg^(-1),the vertical wind shear from 0 to 6 km is 7×10^(-3) s^(-1),the mean values of the 0℃layer heights are 4656 and 4069 m,and the mean values of the-20℃layer heights are 8070 and 7054 m,respectively.(3)Hailstorms require larger K-index values,greater △T_(850-500),and stronger low-level warm air for development.Furthermore,hailstorms are associated with lower 0℃and-20℃layer heights,as the lower 0℃layer heights can prevent hailstones from melting during the descent.Moreover,the impact of subsurface factors on different severe convective weather events varies,with altitude being the primary factor influencing the distribution of hailstorms in the Hetao Irrigation Area.

关 键 词：强对流天气 短时强降水 冰雹 物理量 

分 类 号：P458.2[天文地球—大气科学及气象学]