摘要
利用基于拉格朗日方法的HYSPLIT_4轨迹模式,结合地基GPS-MET观测资料,对2019年6月24~26日中昆仑山北坡一次持续性暴雨天气大尺度水汽输送特征及水汽源地进行分析,阐明了干旱区强降水期间大尺度环流异常与水汽持续接力输送过程的关系。结果表明:(1)降水前副热带高压(简称副高)位置异常偏西,副高外围偏南气流造成高原增湿明显。强降水期间,副高继续向西北伸展,低纬度水汽沿印度夏季风环流向北输送,经青藏高原接力输送至暴雨区,与塔什干低涡前偏南气流共同构成了中昆仑山北坡持续性强降水的水汽输送通道,水汽持续接力输送造成暴雨区可降水量(PWV)出现两次急剧增湿过程,测站PWV峰值达到气候平均值近2倍。(2)300 hPa温度异常对于本次中昆仑山北坡持续性大暴雨天气水汽输送具有重要的作用。降水前和降水期间,300 hPa暖异常中心激发200 hPa反气旋式环流异常和经向风正异常中心,同时,在暖异常中心南侧(印度半岛北部)和西侧,激发500 hPa反气旋式环流异常中心和气旋式环流异常中心,反气旋式环流后部经向风正异常中心将低纬度地区暖湿气流向北输送,与气旋式环流东部偏南气流在暴雨区汇合,为持续性暴雨的发生提供充沛的水汽供应。
Combining ground-based GPS-MET observation data with the HYSPLIT_4 trajectory model based on the Lagrange method,this study analyzed the large-scale water vapor transport characteristics and sources during a persistent heavy rainstorm event on the northern slope of the middle Kunlun Mountains.The relation between the large-scale circulation anomaly and water vapor continuous relay transport during heavy rainfall in arid areas was clarified.The results showed that:(1)Before precipitation,the subtropical high was abnormally westward,and the southward airflow on the periphery of the subtropical high caused obvious humidification over the Tibet Plateau.During the heavy rainfall,the subtropical high extended northwest,and water vapor from low latitude was conveyed to heavy rainfall areas along the Indian summer monsoon circulation and Tibet Plateau.This water vapor converged with the southern airflow in front of the Tashkent low vortex,which constituted the water vapor transport channel for this heavy rainstorm.This mechanism resulted in two rapid humidification events over the heavy rainstorm station.The peak precipitable water vapor levels of the station were nearly two times the climatic average.(2)Temperature anomalies at 300 hPa played an important role in the water vapor transport during the heavy rainstorm.Before and during the event,the 300-hPa warm anomaly center excited the 200-hPa anticyclonic circulation anomaly center and meridional wind positive anomaly center.Meanwhile,the 500-hPa anticyclonic circulation anomaly center and cyclonic circulation anomaly center were excited in the south and west of the warm anomaly center(north of the Indian Peninsula).At the back of anticyclonic circulation at 500 hPa,warm and wet air was transported northward along the positive windward anomaly center at low altitudes.This air then converged with southern airflows from the east of cyclonic circulation in the rainstorm area,providing an abundant water vapor supply for persistent rainstorms.
作者
刘晶
周雅蔓
李建刚
曾勇
仝泽鹏
江雨霏
杨莲梅
周玉淑
LIU Jing;ZHOU Yaman;LI Jiangang;ZENG Yong;TONG Zepeng;JIANG Yufei;YANG Lianmei;ZHOU Yushu(Institute of Desert Meteorology,China Meteorological Administration,Ürümqi 830002;Xinjiang Cloud Precipitation Physics and Cloud Water Resources Development Laboratory,Ürümqi 830002;Field Scientific Observation Base of Cloud Precipitation Physics in West Tianshan Mountains,Ürümqi 830002;Xinjiang Meteorological Bureau,Ürümqi 830002;Laboratory of Cloud–Precipitation Physics and Severe Storms,Institute of Atmospheric Physics,Chinese Academy of Science,Beijing 100029;School of Earth Sciences,University of Chinese Academy of Sciences,Beijing 100049)
出处
《大气科学》
CSCD
北大核心
2024年第5期1711-1727,共17页
Chinese Journal of Atmospheric Sciences
基金
新疆维吾尔自治区自然科学基金项目2023D01B06、2022D01D86
新疆气象局引导性项目YD2023001
天山英才培养计划项目2022TSYCLJ0003
新疆维吾尔自治区重点研发任务专项项目2023B03019-1。
关键词
中昆仑山北坡
持续性暴雨
水汽输送
大气环流异常
Northern slope of the middle Kunlun Mountains
Persistent precipitation
Water vapor transport
Atmospheric circulation anomaly
