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投稿时间：2011-09-27 修订日期：2012-02-13
投稿时间：2011-09-27 修订日期：2012-02-13
中文摘要: 利用WRF模式对2010年1月6—7日新疆北部的暴雪过程进行了数值模拟和诊断分析。分析表明，巴尔喀什湖冷涡与新疆以北南压的冷涡横槽的结合过程，以及相应的中高层急流核传播和发展是造成此次暴雪的关键天气过程，并据此建立了暴雪过程的天气学概念模型。通过温度平流以及锋生函数的诊断表明，地形前方的中尺度辐合对于低层局地锋生有正的贡献，而与潜热释放对应的垂直运动项产生了最强的锋生。进一步通过锋面次级环流的诊断表明，低层锋生强迫的垂直运动较为重要。在地形的影响下，低层冷空气在阿勒泰山前有一定的堆积过程，中高层锋面与低层锋面将发生分裂。由地形因素造成的锋面结构变化对于对降雪的微物理过程有明显影响，6日白天的降水与在地形前爬升的暖性气流以及中高层层云降水有密切关系，但降水量相对较小；6日20时以后地形前方暖平流增强并伴有较为清楚的锋生，而分裂过山的锋面结构形成了明显的冰晶播撒 繁殖机制，降水效率有明显增加，因此在7日白天降雪明显增强。
中文关键词: 暴雪， 锋生， 地形作用， 云微物理过程
Abstract:Numerical simulation and diagnosis are applied to the heavy snow event happening during 6-7 January 2010 in North Xinjiang by using WRF model. The combination of the cold vortex near Balkhash Lake and the south moving trough from North Xinjiang, as well as the propagation and developing of the upper air jet was the key process connected with this serious blizzard. The synoptical conceptual model is set up for this heavy snow event. It is revealed through the diagnosis of temperature advection and frontogenesis function that, the mesoscale convergence in front of the topography led to the active contribution to the frontogenesis, and the vertical motion term in the frontogenesis function explained the most part of the active frontogenesis. The vertical movement due to the secondary circulation forced by the frontogenesis is the most importrant component through the frontogenesis secondary ciruculation diagnosis. Due to the topography effect the cold air was depositing before the mountain, and the front split into upper level part and lower part, and the change in the structure of front has obvious impact on the microphysical process of precipitation. The relative light precipitation happening in the daytime of 6 January 2010 is closely connected with the warm flow ascending along the topography and the stratus cloud in the upper level. After 20:00 BT 6 January, the warm advection was strengthened with distinct frontogenesis, the seeder feeder mechanism was formed by the split front structure, and the snowfall intensified clearly due to this more efficient microphysical process.
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基金项目:公益性行业(气象)科研专项(GYHY201106007)资助
引用文本：
陈涛,崔彩霞,2012.“2010.1.6”新疆北部特大暴雪过程中的锋面结构及降水机制[J].气象,38(8):921-931.
CHEN Tao,CUI Caixia,2012.The Frontal Structure and Precipitation Mechanism in the 6 January 2010 Heavy Snowfall Event Happening in North Xinjiang[J].Meteor Mon,38(8):921-931.
陈涛,崔彩霞,2012.“2010.1.6”新疆北部特大暴雪过程中的锋面结构及降水机制[J].气象,38(8):921-931.
CHEN Tao,CUI Caixia,2012.The Frontal Structure and Precipitation Mechanism in the 6 January 2010 Heavy Snowfall Event Happening in North Xinjiang[J].Meteor Mon,38(8):921-931.