2010年3月14日华北强降雪的模拟和特征分析  

Numerical Simulation and Feature Analysis of the Heavy Snowfall Event of 14 March 2010 over North China

作　　者：张恒德[1] 宗志平[1] 安新宇 

机构地区：[1]中国气象局国家气象中心,北京100081 [2]赤峰市气象局,内蒙古赤峰024000

出　　处：《沙漠与绿洲气象》2013年第2期1-8,共8页Desert and Oasis Meteorology

基　　金：公益性行业(气象)科研专项(GYHY201306015);气象关键技术集成技术项目(CAMGJ2012M60)

摘　　要：主要对2010年3月14日华北强降雪进行了模拟、诊断和特征分析。此次华北降雪在中、低层主要受西风槽、低涡及切变线影响,蒙古气旋东移加强、地面倒槽发展及东风回流建立构成了有利地面天气形势,西北涡、强势的西南暖湿气流及稳定的环渤海高压对此次强降雪至关重要。垂直速度、散度、涡度、螺旋度的分布和演变反映出在此次降雪过程中,强降雪区出现了很强的辐合上升运动,降雪区上空螺旋度呈"下负上正"的垂直结构,螺旋度大值区对应强降雪中心;而锋生条件为降雪的形成和维持提供了一定的能量;相对湿度和水汽通量散度的分布说明强降雪区整层湿度较大,且水汽供应充足。This paper simulated and investigated a heavy snowfall event over North China on 14 March,2010. The results showed that the heavy rainfall process was well simulated by the meso- scale numerical model MMS. Vortex and trough at mid-low-level had main effect on the snowfall. Mongolia cyclone moving eastward and intensifying, reversed trough developing, and east backflow formation in surface layer are propitious to the heavy snowfall. The northwest vortex, strong southwest warm moist stream and stable high around Bohai Sea played key roles on the snowfall. According to the change of vertical velocity, divergence, vorticity, helicity and frontogenetic function, it was obviously found that the air in heavy snowfall area.converged and ascended .Tile vertical profile of helicity over heavy snowfall area showed the opposite pattern with negative in the low-middle-level and positive in upper-level in troposphere,and the large negative helicity area corresponded to the center of snowstorm. Moreover, the front generating condition provided energy for snowfall forming and maintaining. Distribution of relative humidity and moisture flux divergence showed that there was high relative humidity and the strong moisture convergence over the heavy snowfall area and water vapor supporting was enough.

关 键 词：暴雪 西南气流 数值模拟 回流 螺旋度 

分 类 号：P456[天文地球—大气科学及气象学]