摘要
利用常规观测资料和NCEP 1°×1°逐6 h再分析资料,对辽宁省2009年2月12～13日和2010年3月14～15日2次区域性暴雪过程的环流特征和物理量场进行对比分析。结果表明,冬季乌拉尔山阻高的稳定维持,有利于中纬度高空槽的生成,它的东移与辽宁降雪密切相关;2次过程在50°～60°N建立的低涡以及东北西南向的大槽是产生辽宁区域性暴雪的主要影响系统。物理量场如螺旋度、涡度、温度平流和水汽通量散度等为暴雪落区和持续时间的预报有很好的指示意义。
Based on the conventional observation data and reanalysis data（horizontal resolution 1°×1°） from NCEP,circulation change and physical quantity of the two regional snowstorm processes in Liaoning on between 12th-13th Feb 2009 and 14th-15th Mar 2010 were compared.The results showed that many analogies exist between the two processes.Both processes occurred under stable Ural blocking high and the low vortex and trough between 50°N and 60°N.Low-level jet established before the snow provides enough moisture and energy.Relative helicity and vorticity both the processes who show positive values in the lower-level and negative values in the upper-level lead to a coupling of the intense divergence on upper levels and intense convergence on lower levels as well as intensive ascending motion.That is the dynamic mechanism of the heavy snowstorm occurrence.When the southwest airflow on lower levels meets the inrush of arid cold air on upper levels,snowstorm happens.While the lower level is taken over by the cold air,the snow is on the way out.The both processes have humidity frontal zone on the east of Liaoning and the frontal zone continuing for a long time play an important role in the heavy snow in the east.
出处
《安徽农业科学》
CAS
2012年第32期15812-15815,15887,共5页
Journal of Anhui Agricultural Sciences
基金
中国气象局预报员专项(CMAYBY2011-007)
中国气象局公益性行业专项(GYHY2010-06001)
关键词
区域暴雪过程
乌拉尔山高压脊
环流形势
对比分析
辽宁省
Regional snowstorm processes
Ural blocking high pattern
Circulation pattern
Comparative analysis
Liaoning Province
