2020年关中西部首场大范围暴雨诊断分析  

Diagnostic Analysis of the First Large-Scale Rainstorm in the Western Guanzhong Region in 2020

作　　者：卢晔[1] 贺瑶 任欢[1,2] 张震宇 边赟 李涵钰[1] Lu Ye;He Yao;Ren Huan;Zhang Zhenyu;Bian Yun;Li Hanyu(Baoji Meteorological Bureau,Baoji,Shannxi 721006,China;Key Laboratory of Eco-Environment and Meteorology for the Qinling Mountains and Loess Plateau,Xi'an,Shannxi 710016,China)

机构地区：[1]宝鸡市气象局,陕西宝鸡721006 [2]秦岭和黄土高原生态环境气象重点实验室,陕西西安710016

出　　处：《绿色科技》2023年第16期60-63,67,共5页Journal of Green Science and Technology

基　　金：宝鸡市气象局自立科研项目(编号:202003,202005);陕西省气象局秦岭和黄土高原生态环境气象重点实验室开放研究基金课题(编号:2021Y-13)。

摘　　要：利用常规气象观测资料及NCEP 2.5°×2.5°再分析资料,从环流形势、物理量场等方面对2020年关中西部首场大范围暴雨天气过程进行了诊断分析。结果表明:此次降雨过程持续时间较长,过程累积雨量大,降水时段集中且雨强大。500 hPa短波槽、低层切变线、地面冷锋是造成此次暴雨天气的主要影响系统;水汽通量辐合区和低层比湿大值区均与强降水时段对应,700 hPa和850 hPa的水汽输送和辐合为暴雨产生提供了强水汽辐合条件;“高层辐散、低层辐合”的结构使整层产生了有组织的上升运动,将低层水汽和能量输送至高层,为暴雨形成提供了动力条件;同时,宝鸡上空700 hPa以下为冷平流,700 hPa及以上为暖平流,导致宝鸡上空冷暖空气交汇,形成锋区,有利于暴雨产生。另外,强降水时段对应k指数大值区,不稳定能量条件较好,也是此时段出现最大雨强的重要原因之一。Based on the conventional meteorological observation data and NCEP 2.5°×2.5°reanalysis data,the first large-scale rainstorm weather process in western Guanzhong in 2020 was analyzed from the aspects of circulation situation and physical quantity field.The results show that the duration of the rainfall process is long;the cumulative rainfall is large;the precipitation period is concentrated and the rain is strong.The 500hPa short-wave trough,the low-level shear line and the surface cold front are the main influencing systems of the rainstorm.The convergence area of water vapor flux and the large specific humidity area of the lower layer correspond to the heavy precipitation period,and the water vapor transport and convergence of 700 hPa and 850 hPa provide the strong water vapor convergence conditions for the rainstorm.The structure of"divergence at the upper level and convergence at the lower level"makes the whole layer produce organized upward movement,transporting water vapor and energy at the lower level to the upper level and providing dynamic conditions for the formation of rainstorm.At the same time,the cold advection is below 700 hPa over Baoji,and the warm advection is above 700 hPa,resulting in the intersection of cold and warm air over Baoji,forming a front area,which is conducive to the generation of heavy rain.In addition,the heavy precipitation period corresponds to the K-index large value region,and the unstable energy conditions are better,which is also one of the important reasons for the heaviest rain and intensity in this period.

关 键 词：暴雨 环流形势 物理量 不稳定 

分 类 号：P458.1[天文地球—大气科学及气象学]