甘肃省河西地区2次强寒潮天气过程分析

摘要

从寒潮天气过程发生的环流形势的演变过程及各种物理量变化特征如涡度、垂直速度、温度平流等方面对2011年3月12—14日、2012年4月22—24日甘肃省河西走廊地区2次春季寒潮天气过程的特征进行了对比分析.分析发现这2次春季典型寒潮天气过程均是出现在亚欧中高纬地区环流形势由纬向型向经向型转换过程中,前期温度一般较往年同期异常偏高;强盛的冷平流造成气温大幅下降,地面冷高压强烈发展最终形成甘肃省河西地区寒潮天气;但2次寒潮过程环流形势也有所不同,天气过程的强度也不同.%In this paper,the characteristics of the twice cold wave during the spring on March 12 to March 14 in 2011 and April 22 to April 24 in 2012 in Hexi Corridor region were compared and analyzed from the aspects of the evolution of circulation patterns that occurred in cold weather process and variation of various physical quantities such as vorticity,vertical speed,temperature advection,etc. The following conclusions were drawn in major:These two typical cold wave weather processes both occurred in spring and occurred in high latitudes in Asia and Europe during the process of the zonal circulation pattern converted to the meridional circulation pattern,and the previous temperature was generally higher abnormally than the same period before. Strong cold advection caused temperatures dropped significantly,clod high pressure on surface develop intensively and form cold wave weather in Hexi region eventually. But,there were some different circulation situations between the twice processes,so was the strength of the two weather processes.