2008年初湖北省低温雨雪冰冻天气温度平流配置分析

Temperature Advection Structure of Low-temperature Process with Freezing Rain and Snow in Hubei Province in 2008

利用NCEP/NCAR再分析资料,对2008年1月11日—2月1日湖北省低温雨雪冰冻过程进行温度平流空间分布诊断分析。结果表明:低温雨雪冰冻期间,湖北省近地层不断有弱冷空气补充和渗透;中层暖平流、低层冷垫和南方沿冷垫向上爬升的暖空气是湖北省降雪最基本的条件,而湖北省东部出现强降雪的另一个更重要的原因就是低层偏东回流带来的暖平流;当冷空气充斥湖北省上空整层大气时,则预示雨雪将减弱停止。

Based on the daily NECP/NCAR reanalysis data, the spatial distribution of temperature advection is analyzed in the process of low-temperature with freezing rain and snow from 11 January to 1 February 2008. Results show that, during the process, the weak cold air is continually supplied to the surface layer in Hubei Province. The warm advection in middle layer, the cold wedge in low layer, and the warm air from south climbing along the cold wedge are the most basic conditions, which leads to the snow process in Hubei Province. Another reason inducing the heavy snow in the east of Hubei is the warm advection caused by the eastern reflow in the low layer. When the cold air is full over Hubei Province, the rain and snow will stop.