摘要
利用NCEP再分析资料和常规气象观测资料,分析了2006年1月18-19日发生在河南省的一次暴雪过程,结果表明,这次暴雪过程中存在干侵入现象。干侵入的发生发展对暴雪过程具有重要作用:干侵入沿相当位温密集带向下向北传播,引起对流层低层气旋性涡度发展,增强辐合上升运动,导致降水的增强;高层干冷空气向下注入,引起温度场扰动,在对流层中低层形成逆温层,有利于暴雪天气的发生;高空急流入口区北侧的下沉运动为对流层高层干空气和高位涡的下传提供了动力条件。
The heavy snow process in Henan province on January 18--19, 2006 was studied with NCEP reanalysis and routine meteorological observation data. Results indicated that there existed dry intrusion phenomena and its occurrence and development had great important function on this heavy snow process. Dry intrusion extended down and north along dense area of potential equivalent temperature isoline, which brought development of cyclone eddy on low troposphere, boosted up convergence occurrence, and caused precipitation to manifold. Dry and cold air injected downwards from high level and made temperature disturbance. The formation of inversion layer on low-middle troposphere made for heavy snow weather. Sinking motion from north side of entrance of upper level jet provided dynamical condition for dry air and high potential vorticity transporting downwards.
出处
《气象与环境科学》
2007年第2期43-47,共5页
Meteorological and Environmental Sciences
关键词
干空气侵入
暴雪
高空急流
dry intrusion
heavy snow
upper level jet
