主办单位:中国气象局沈阳大气环境研究所
国际刊号:ISSN 1673-503X
国内刊号:CN 21-1531/P

气象与环境学报 ›› 2017, Vol. 33 ›› Issue (6): 16-24.doi: 10.3969/j.issn.1673-503X.2017.06.003

• 论文 • 上一篇    下一篇

巴州地区一次罕见短时强降水过程诊断分析

刘国强1, 佟欣怡2, 杨莲梅3, 周雪英1, 霍达1   

  1. 1. 新疆巴州气象局, 新疆 库尔勒 841000;
    2. 新疆气候中心, 新疆 乌鲁木齐 830002;
    3. 中国气象局乌鲁木齐沙漠研究所, 新疆 乌鲁木齐 830002
  • 收稿日期:2017-01-08 修回日期:2017-03-29 出版日期:2017-12-30 发布日期:2017-12-30
  • 作者简介:刘国强,男,1992年生,助理工程师,主要从事短期、短时临近天气预报及相关研究,E-mail:18251912890@163.com。
  • 基金资助:
    中央级公益性科研所基本科研业务费专项(IDM2016001)和新疆气象局科学技术研究项目(MS201605)共同资助。

Diagnostic analysis of an unusual flash heavy rain in Bayingolin Mongol Autonomous prefecture

LIU Guo-qiang1, TONG Xin-yi2, YANG Lian-mei3, ZHOU Xue-ying1, HUO Da1   

  1. 1. Meteorological Service of Bayingolin Mongol Autonomous Prefecture, Korla 841000, China;
    2. Xinjiang Climate Center, Urumqi 830002, China;
    3. Institute of Desert Meteorology, China Meteorological Administration, Urumqi 830002, China
  • Received:2017-01-08 Revised:2017-03-29 Online:2017-12-30 Published:2017-12-30

摘要: 利用自动气象站逐小时观测资料、实时探空观测资料及NCEP/NCAR (National Centers for Environmental Prediction/National Center for Atmospheric Research)的1°×1°再分析资料,对2016年8月23—24日新疆维吾尔自治区巴州库尔勒地区一次罕见的短时强降水过程主要的环流系统、水汽输送、动力及湿位涡与垂直螺旋度的变化特征进行了诊断分析。结果表明:此次短时强降水天气过程发生在东部型南亚高压显著增强和西西伯利亚至巴尔喀什湖的长波槽缓慢东移的环流背景下,低层风向风速迅速辐合为此次短时强降水过程的发生提供了水汽和动力条件。此次强降水过程的水汽来源主要包括3个部分:乌拉尔山脊前偏北风引导冷空气南下与西风气流汇合于南疆西部地区的西路水汽输送、青藏高原西南侧低涡前部西南气流引导的西南路水汽输送及西太平洋副热带高压引导的偏南水汽输送,其中94.26%的水汽来源于偏西与偏南气流。短时强降水过程发生前期,暴雨区上空左右两侧形成的中尺度环流圈是此次短时强降水过程发生的主要动力机制;垂直螺旋度的发展演变与强降水密切联系,当高层负的垂直螺旋度与低层正的垂直螺旋度配置耦合时,有利于短时强降水的发生。短时强降水过程发生在θse线密集且陡立的区域内,高层高值MPV1的下传触发了位势不稳定能量的释放,促进了强降水的产生。

关键词: 水汽输送, 动力机制, 湿位涡, 倾斜涡度, 垂直螺旋度

Abstract: Based on the hourly precipitation,real-time radiosonde data and the NCEP/NCAR(National Centers for Environmental Prediction/National Center for Atmospheric Research)reanalysis data with resolutions of 1°×1°,we analyzed the characteristics of critical circulation systems,vapor transportation,dynamics,moist potential vorticity and vertical helicity of a flash heavy rain event happening in Bayingolin Mongol Autonomous Prefecture on August 23 to 24,2016.The results indicate that the flash heavy rain occurs under the following circulation conditions:South Asia high with an eastern pattern increases dramatically and the long wave trough from Western Siberia to the Balkhash Lake moves eastward slowly.The rapid convergence of the wind direction and wind speed at the lower tropospheric level provides the power and vapor conditions for the flash heavy rain.There are three components for the water vapor sources at three rainstorm stages.One is the western water vapor transport produced by the convergence between the southward cold air guided by the northerly wind in front of the Ural ridge and the westerly flow;the second is the west-southern water vapor transport carried by the low vortex at the southwest side of Tibetan Plateau;the third is the southerly water vapor transport brought by the pacific subtropical high,in which 94.26% of water vapor transportation comes from the west and south airflow.At the early stage before the flash heavy rain occurred,a mesoscale vertical circulation cell forming over the east and west sides of the heavy rainfall area is the main dynamic mechanism for its occurrence.The vertical helicity evolution is closely related to the flash heavy rain.The appearance of heavy precipitation usually accompanies with the coupling between the negative vertical helicity value at the upper level and positive one at the lower level.Heavy rain often appears in the area with steep and dense θse lines.The downward spread of high moist potential vorticity at the upper tropospheric level triggers the release of potential instability energy,resulting in the occurrence of heavy rain.

Key words: Water vapor transport, Dynamical mechanism, Moist potential vorticity, Slantwise vorticity development, Vertical helicity

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