川西高原和攀西地区不同级别短时强降水环境参量特征对比分析  

Characteristics of Environmental Parameters of Short-duration Heavy Rain in Western Sichuan Plateau and Panxi Region

作　　者：张武龙[1,2] 杨康权 康岚[1,2] 银航 ZHANG Wulong;YANG Kangquan;KANG Lan;YIN Hang(Sichuan Provincial Meteorological Observatory,Chengdu 610072,China;Heavy Rain and Drought-Flood Disasters in Plateau and Basin Key Laboratory of Sichuan Province,Chengdu 610072,China)

机构地区：[1]四川省气象台,成都610072 [2]高原与盆地暴雨旱涝灾害四川省重点实验室,成都610072

出　　处：《高原山地气象研究》2024年第2期75-82,共8页Plateau and Mountain Meteorology Research

基　　金：国家重点研发计划项目(2021YFC3000900);中国气象局气象能力提升联合研究专项重点项目(22NLTSZ006);四川省重点研发项目(2022YFS0542,2022YFS0540);四川省重点实验室项目(SCQXKJZD202101,SCQXKJYJXZD202101,SCQXKJYJXMS202112);西南区域创新团队项目(XNQYCXTD-202202);中国气象局创新发展专项(CXFZ2023J016,CXFZ2024J013);四川智能网格预报创新团队项目(SCQXCXTD-202201)。

摘　　要：利用2010—2021年5—9月川西高原和攀西地区62个国家级自动站逐小时观测资料及时间分辨率为1 h的ERA5再分析资料,对比分析了两区域不同级别短时强降水发生发展过程中水汽、热力和垂直风切变等环境参量特征。结果表明:川西高原和攀西地区短时强降水主要集中在6—8月,午后至前半夜是川西高原短时强降水的高发时段,攀西地区则表现出明显的夜雨特征。就川西高原而言,较好的水汽、热力条件和较强的垂直风切变、上升运动均有利于高级别短时强降水的产生;不同级别短时强降水的CAPE值差异显著,1100 J·kg^(−1)可作为判断是否出现20 mm·h^(−1)以上短时强降水的参考阈值。就攀西地区而言,不同级别短时强降水在暖云层厚度、700 hPa比湿、700 hPa假相当位温、CAPE、0~3 km垂直风切变等环境参量的值域分布上均存在明显差异;当700 hPa比湿大于13 g·kg^(−1)、CPAE值超过1100 J·kg^(−1)、0~3 km垂直风切变达到10 m·s^(−1)时,极易出现50 mm·h^(−1)以上的短时强降水。Based on the hourly observational datasets reported by 62 meteorological stations and hourly ERA5 reanalysis in Western Sichuan Plateau and Panxi region from May to September during 2010—2021,the characteristics of environmental parameters such as water vapor,thermodynamic variables and vertical wind shear were investigated and contrasted in the occurrence and development of shortduration heavy rain under different intensities.Results showed that the short-duration heavy rain mainly occurred from June to August.The high occurrence period was from afternoon to the first half of night in Western Sichuan Plateau,and the feature of night rain was obvious in Panxi region.The better water vapor and thermal conditions,stronger vertical wind shear and ascending motion were benefit for the higher intensity of short-duration heavy rain in Western Sichuan Plateau.The Convective Available Potential Energy(CAPE)of different levels of short-term heavy precipitation were significantly different,and 1100 J·kg^(−1) could be the value to judge whether or not the rainfall reached 20 mm·h^(−1).There were distinct differences in the distribute ranges of warm cloud level thickness,700 hPa specific humidity and potential pseudo-equivalent temperature,CAPE and 0~3 km vertical wind shear in the short-duration heavy rain under different intensities in Panxi region.The rainfall exceeding 50 mm·h^(−1) was caused easily when certain conditions were met,including the specific humidity at 700 hPa greater than 13 g·kg^(−1),CAPE over 1100 J·kg^(−1) and 0~3 km vertical wind shear attaining 10 m·s^(−1).

关 键 词：川西高原 攀西地区 短时强降水 环境参量 ERA5再分析资料 

分 类 号：P458.121.1[天文地球—大气科学及气象学]