一次冷涡背景下强对流不稳定条件的成因分析

利用常规观测资料及NCEP再分析资料,在分析环流背景、探空资料的基础上,通过选取不同的高度和温度,对比研究四种CAPE以及CAPE场与地面要素场的关系,对发生在辽宁沈阳的一次冷涡背景下的强对流天气进行不稳定条件成因分析.结果表明,水汽潜热是不稳定能量的主要组成部分,冷涡背景下低层暖湿平流、高层冷干平流有利于不稳定能量的累积,从而导致强对流天气的发生；对流温度CAPE可以反映午后发生强对流所必需的不稳定能量,对强对流天气预报具有一定指示意义.

Causative Analysis of Strong Convective Unstable Conditions Under a Cold Vortex

Using conventional observation data and NCEP reanalysis data, the causes for unstable conditions of a strong convective weather under the background of the cold vortex in Shenyang City of Liaoning Province were analyzed by studying four kinds of CAPE and the relationship of CAPE field and surface meteorological factors. The results show that the water vapor latent heat is the main part of the unstable energy. Under the background of the cold vortex, the low level warm and moist advection, and high level cold and dry advection were advantageous to unstable energy accumulation, which leads to the occurrence of strong convective weather. The convective temperature CAPE can refect the unstable energy required by the afternoon strong convective occurrence, and it has a certain significance to the forecast of strong convective weather.