利用局地经向环流对河南一次连阴雨过程的定量诊断

Quantitative Diagnosis on a Continuous Rain Event in Henan by Using Local Meridional Circulation Model

利用2.5°×2.5°NCEP/NCAR再分析资料和改进的局地经向环流线性模式,定量诊断了2011年9月5—19日河南省秋季连阴雨天气的形成机理,并利用局地经向环流的垂直分量与降水量滞后相关的分析,研究了这次连阴雨过程主要物理因子的演变特征。结果表明:(1)潜热加热、平均经向温度平流、平均西风动量的纬向平流和平均纬向温度平流是导致2011年9月河南省秋季连阴雨天气形成的主要物理因子。(2)潜热加热和平均纬向温度平流是造成此次连阴雨发生的主要物理因子;平均纬向温度平流、平均经向温度平流和平均西风动量的纬向平流是造成此次连阴雨发展或持续的主要物理因子;潜热加热、平均西风动量的纬向平流和平均纬向温度平流是造成此次连阴雨结束的主要物理因子。

Based on 2 .5°×2 .5°NCEP/NCAR reanalysis data and the improved local meridional circulation model,quantitative diagnosis for the mechanism was performed on a continuous autumn rain event in Henan Province from 5 to 19 September 2011,and evolution characteristics of the main physical factors for the continuous autumn rain event were proposed by means of lag correlation analysis of the upward branch of a local meridional circulation and precipitation over Henan.The results showed that,(1 )latent heat-ing,average meridional temperature advection,zonal advection of westerly momentum and average zonal temperature advection are the main physical factors which caused the continuous rainy weather to occur o-ver Henan Province in September 2011.(2)The latent heating and average zonal temperature advection are the main physical factors for the start of the rainy weather;zonal advection of average westerly momen-tum and average meridional temperature advection as well as average zonal temperature advection are the physical factors for the continuous rainy weather;latent heating,zonal advection of average westerly mo-mentum,average meridional temperature advection and average zonal temperature advection are also the main physical factors for the continous rainy weather ending.