安徽地区山地与平原冻雨天气成因及特征分析  

Analysis of forming reason of freezing rain weather and its characteristics in mountain and plain of Anhui province

作　　者：江杨[1] 何志新[1] 周昆[1] 朱红芳[1] 王东勇[1] 

机构地区：[1]安徽省气象台,安徽合肥230031

出　　处：《气象与环境学报》2016年第2期11-17,共7页Journal of Meteorology and Environment

基　　金：安徽省预报员专项"安徽冻雨天气的气象要素分析"(KY301311);华中区域气象中心科技发展基金项目"多部多普勒雷达资料在数值模式中的同化应用研究"(QY-Z-201201)共同资助

摘　　要：为了探讨冬季冻雨天气成因并提高冻雨天气的预报能力,利用常规气象观测资料、加密气象观测资料和NCEP再分析资料,对2010年2月安徽省一次冻雨过程进行天气学分析,利用WRF中尺度模式对此次冻雨过程进行数值模拟,并对冻雨发生的物理量场和层结条件进行分析.结果表明:此次安徽省南部山区和北部平原地区的冻雨天气过程主要是由于北方强冷空气快速南下,在安徽省境内大陆冷高压与西太平洋副热带高压相遇,形成鞍形场切变线引起的.从模拟结果来看,此次安徽省山区与平原地区冻雨天气的成因和层结特征均有较大区别,山区冻雨天气的形成与山脉对冷暖空气的阻挡和抬升有关;而平原地区冻雨天气的形成需强冷空气快速南下,产生有利于冻雨天气发生的层结结构.山区冻雨天气发生时,具有较大的逆温梯度和较高的冷心高度;平原地区冻雨天气发生时,近地面有较大的负变温中心和较高的冷心高度,但与逆温梯度不存在稳定的对应关系.冻雨天气的产生与逆温强度、冷垫厚度及其变温幅度均有一定的关系,是一个复杂的物理过程.In order to investigate the causes of winter freezing weather and improve freezing rain forecasting accuracy,synoptic characteristics of a freezing event in February of 2010 in Anhui province were analyzed based on conventional observation data,intensive observation data and the NCEP reanalysis data. At the same time,numerical simulation by a WRF model for this process was performed,and physical field and stratification condition were discussed. The results showthat freezing rain in the south mountain area and north plain area of Anhui province is mainly caused by strong cold air moving down south quickly,which makes cold continental high meeting the western Pacific subtropical high and forming a saddle shape pressure field. Analysis of simulation suggests that forming reasons and stratification features of this process in the mountain and plain differ significantly. Forming of freezing rain in the mountain area is related to block and lifting of mountain to cold and warm air,while it needs strong cold air moving southward rapidly in the plain area and produces stratification structure that is favorable to generate freezing rain weather. In the mountain area, it has great temperature inversion gradient and higher cold center height when freezing rain weather occurs. In the plain,it has great negative temperature center and higher cold center height near the surface when freezing rain weather occurs,while there is not stable corresponding relation with temperature inversion gradient. Generation of freezing rain weather is a complex physics process,and it has relationship with intensity of temperature inversion,height of cold pad and amplitude of temperature change.

关 键 词：冻雨 WRF模式 逆温层 数值模拟 

分 类 号：P426.63[天文地球—大气科学及气象学]