2008年初浙闽山区严重雨雪冰冻天气过程诊断分析  

An analysis on severe ice freezing and snow weather process occurring in Zhejiang and Fujian mountains in early 2008

作　　者：年瑶[1] 方娟[1] 

机构地区：[1]南京大学大气科学学院中尺度灾害性大气教育部重点实验室,南京210093

出　　处：《南京大学学报（自然科学版）》2010年第3期284-295,共12页Journal of Nanjing University（Natural Science）

基　　金：国家重点基础研究发展规划项目(2009CB421502);国家气象中心"天气要素精细预报业务系统建设与改进项目"和"面向TIGGE的集合预报关键应用技术研究"(GYHY(QX)2007-6-1)

摘　　要：本文利用NCEP(1°×1°)逐6 h分析资料、FY-2C卫星云图资料和常规气象观测资料,从环流背景、锋面垂直结构、大气层结条件、动力抬升等方面入手,对2008年1月25日-29日浙闽山区雨雪冰冻天气过程进行了天气形势分析和天气学诊断分析.得到如下几点结论:1)2008年1月初极地环流异常,亚洲上空出现持久的极涡且中心明显偏强,与此次雨雪冰冻天气关系极为密切;东亚倒Ω流型长时间稳定维持,有利于冷空气不断补充南下;2)南支槽活跃,西南暖湿气流为浙闽山区输送了大量的水汽,维持在低空850 hPa上的切变线为冷暖空气的交汇和中尺度锋生提供了条件;3)由于浙闽山区地形影响,冷空气在南下过程中受阻,东侧冷锋越山南下与西段冷锋迎面会合,发生锢囚,锢囚结构在准地转Q矢量场上表现较为明显;4)中低空深厚锋面逆温层的存在和低于0℃的地表温度为冻雨天气的发生提供了必要条件,大气层呈低空冷、中间暖、高层冷的结构对冻雨的形成非常重要,说明冻雨天气与大气垂直结构密切相关.The present work discusses the ice freezing and snow weather process occurring in Zhejiang and Fujian Mountains from 25 to 29 January 2008.The large-scale circulation,frontal structure,stratification and dynamical lifting associated with this process are investigated in detail through the reanalysis data from the National Centers for Environmental Prediction-National Center for Atmospheric Research（NCAR-NCEP） and FY-2C satellite cloud images,as well as routine meteorological observation data.It is found that the circulation in the polar region was anomalous in early 2008.The polar vortex over the Asian area was persistent and strong,which induced the advection of dry and cold Siberia air down to Zhejiang and Fujian Mountains.Under the effect of the topography,the cold air was blocked in the mountainous area and then the occluded front formed.Meanwhile,a strong persistent southwesterly transported warm and moist air from the Bay of Bengal and South China Sea to Zhejiang and Fujian Mountains.The deep inversion in the lower troposphere being resulted from the advection of dry and cold air from the north and warm and moist air from the south played a vital role in the formation of freezing rain.

关 键 词：极涡 锢囚锋 温度平流 冻雨 逆温 

分 类 号：P458[天文地球—大气科学及气象学]