摘要
2017年8月27-31日中国东北地区出现了一次大范围降温过程,部分地区出现降水,其中漠河县、阿尔山市在28日均出现了初雪.为研究此次雨雪降温天气的形成原因,采用常规气象观测资料、ERA-Interim再分析资料、卫星云图资料,对大尺度环流背景、冷涡的发生发展机制和物理量场的配置进行诊断分析.结果表明:东北冷涡是这次雨雪降温过程的主要影响系统.干冷空气的入侵是冷涡形成和维持冷心结构的重要因素.在高纬冷空气随冷涡南下的过程中,有高空冷锋区逐渐向南移动,低层温度急剧下降是形成降雪的重要原因.水汽沿冷涡环流逆时针输送,大值区主要位于冷涡东侧,并随冷涡东移.冷涡降水取决于冷涡风场的结构变化特征,上升气流较强时,降水也较强.
A process of large scale cooling occurred in Northeast China in August 27-31,2017 while precipitation occurred in some areas,and the first snowfall both happened in Mohe County and Aershan Cityin the 28th.In order to study the cause of such as rain and snow these cooling weather,based on the routine meteorological observational data,ERA-Interim reanalysis data and the satellite images,the background of largescale circulation,the occurence mechanism and development of the cold vortex and the configuration of physical quantity fields were diagnosed and analyzed.The results show that:the northeast cold vortex was the main influncial system of the cooling process of rain,snow.The invasion of dry and cold air was an important factor for the formation of cold vortex and the maintenance of cold structure.During the process of cold air in high latitude flowing down the cold vortex,there was a cold frontal zone in high-altitude that gradually moved southward,the sharp drop of low-level temperature was an important cause of snowfall.The water vapor was transported counterclockwise along the cold vortex circulation,the largevalue zone was mainly located on the east side of the cold vortex,and moved eastward with the cold vortex.The precipitation associated with the cold vortex depended on the structural variation characteristics of the cold vortex wind field,when the updraft was strong,the precipitation was also strong.
作者
于佳含
巩远发
YU Jiahan;GONG Yuanfa(College of Atmosphere Science,Chengdu University of Information Technology,Chengdu 610225,China)
出处
《成都信息工程大学学报》
2020年第1期43-54,共12页
Journal of Chengdu University of Information Technology
基金
国家自然科学基金重大研究计划资助项目(91537214)
国家自然科学基金资助项目(41775079,41275080)。
关键词
气象学
天气诊断
东北冷涡
机制分析
雨雪降温
meteorology
synoptic diagnosis
northeast cold vortex
mechanism analysis
rain
snow and cooling
