南疆西部2016年8月4次暴雨过程特征分析  

Characteristics of Four Rainstorm Processes in the West of Southern Xinjiang in August 2016

作　　者：努尔比亚.吐尼牙孜 张超 李泽巍 孙成云 黄艳[3] Nurbiye Tunyaz;ZHANG Chao;LI Zewei;SUN Chengyun;HUANG Yan(Kashi Meteorological Observatory of Xinjiang, Kashi 844000,Xinjiang, China;Xinjiang Meteorological Observatory, Urumqi 830002, China;Hetian Meteorological Bureau of Xinjiang, Hetian 848000, Xinjiang, China)

机构地区：[1]新疆维吾尔自治区喀什地区气象台,新疆喀什844000 [2]新疆维吾尔自治区气象台,新疆乌鲁木齐830002 [3]新疆维吾尔自治区和田地区气象局,新疆和田848000

出　　处：《干旱气象》2019年第2期301-311,共11页Journal of Arid Meteorology

基　　金：新疆维吾尔自治区自然科学基金(2016D01A011)资助

摘　　要：利用常规观测资料、多普勒天气雷达产品、FY-2D卫星云图及NCEP/NCAR再分析资料,对比分析异常环流背景下南疆西部2016年8月4次暴雨过程的形成机理和中尺度系统。结果表明:500 hPa偏强的乌拉尔山高压脊、极地低压和700 hPa青藏高原异常的水汽辐合带及100 hPa南亚高压的东西振荡是南疆西部2016年8月暴雨偏多的环流背景。500 hPa乌拉尔山高压脊的建立、发展、衰退与暴雨有密切联系。850 hPa暖高压脊、500 hPa与850 hPa中低层28℃以上温差与降水强度密切相关,500 hPa以下湿层厚度、700 hPa以下东风气流、地面切变线和干线的差异是暴雨强度、落区、持续时间不同的原因之一。南边界水汽输送是南疆西部暴雨的重要水汽来源,东边界水汽输送是该区域短时强降水的重要补给。卫星云图的湿度梯度利于对流天气的发生,而雷达的强回波、低质心、高云顶结构特征利于短时强降水的发生。Based on the conventional observation data, Doppler radar products at Kashi station, FY-2D satellite cloud images and NCEP/NCAR reanalysis data, the formation mechanism and mesoscale weather system of four rainstorm processes under the anomalous circulation background in the west of Southern Xinjiang in August 2016 were analyzed comparatively. The results show that the more rainstorms in the western part of Southern Xinjiang in August 2016 occurred under the circulation background of the strong Ural Mountains high ridge on 500 hPa and Polar lows, anomalous water vapor convergence zone on 700 hPa over Tibetan Plateau and longitudinal oscillation of South Asia high. And the establishment, development and decline of the Ural Mountain high ridge on 500 hPa were closely related with rainstorms in the western part of Southern Xinjiang in August 2016. The intensity of rainstorm was closely related with 850 hPa warm ridge and temperature difference above 28 ℃ between 500 hPa and 850 hPa, while the differences of humidity layer thickness below 500 hPa, easterly airflow below 700 hPa, surface shear line and dry line resulted in different intensity, falling area and duration of rainstorm. The water vapor transport at the southern boundary was important source of rainstorm in the western part of Southern Xinjiang, while at the eastern boundary it was important supply of short-term heavy rainfall in the area. The humidity gradient on satellite images was conductive to the occurrence of convective weather, while the structures of the strong echo, low centroid and high cloud top of radar were beneficial to the occurrence of shortterm heavy rainfall.

关 键 词：暴雨 中尺度分析 水汽输送 环流背景 南疆西部 

分 类 号：P458.1[天文地球—大气科学及气象学]