山东半岛冷流暴雪过程的个例分析  

Analysis of A Cold-Air Outbreak Snowstorm Event Affected by Taihang Mount in Shandong Peninsula

作　　者：朱营礼[1] 吴增茂[1] 林曲凤 周淑玲 

机构地区：[1]中国海洋大学海洋环境学院,山东青岛266100 [2]烟台市气象局,山东烟台264003 [3]威海市气象局,山东威海264200

出　　处：《中国海洋大学学报（自然科学版）》2010年第S1期1-8,共8页Periodical of Ocean University of China

基　　金：国家自然科学基金项目(40675068)资助

摘　　要：2008年12月4~5日,山东半岛出现了1次冷流暴雪过程,渤海上的辐合带对这次暴雪过程起到了重要的作用。本文利用观测资料和数值模式对这次过程进行了研究,探讨渤海辐合带的发展演变机制及对山东半岛冷流暴雪的影响,并分析了太行山脉对渤海辐合带的影响。结果表明,渤海上空生成的西北东南向的中尺度辐合带造成了以烟台-牟平-文登为中心的西北东南向的降雪带。太行山脉的阻挡作用使绕太行山的西北气流在太行山背风侧形成辐合,同时在低层大气存在1个暖脊,所以在渤海形成了1个西北东南向的辐合带。在西北风的水平平流和非地转风的作用下,渤海辐合带向东北移动,当渤海西北岸出现北风后,渤海辐合带西北部在北风的水平平流作用下向南移动,而渤海辐合带东南部在西北风水平平流和非地转风的作用下,继续向东北移动并与山东半岛北部的海岸锋辐合带合并增强,渤海辐合带西北和东南两部分移动方向的不同造成了辐合带的波动。渤海辐合带增强后登陆山东半岛,造成山东半岛西北东南向降雪带。对这次冷流暴雪个例的分析发现,太行山脉通过形成背风低压中尺度系统直接影响渤海上的中尺度辐合带的发展,而渤海辐合带与山东半岛北岸附近海岸锋的耦合使辐合加强,增强了降雪强度。A severe cold-air outbreak snowstorm occurred in Shandong Peninsula on 4-5 December 2008.A Bohai Sea convergence zone played a very important role in this event.In this paper,several kinds of observations and numerical simulation are used to analyze the mechanism of the Bohai convergence zone.The impact of Taihang Mount on the Bohai Sea convergence zone which resulted in the cold-air outbreak snowstorm was also analyzed.The results indicated that a meso-scale convergence zone oriented in northwest-southeast formed in Bohai Sea and resulted in a snowband oriented in northwest-southeast centered in Yantai,Muping and Wendeng.When northwestly winds flowed around Taihang Mount,a convergence zone formed because of the blocking of Taihang Mount,at the same time,a warm ridge existed in the lower troposphere,so a northwest-southeast convergence zone formed in Bohai Sea.Under the influence of horizontal advection of northwestly wind and ageostrophic velocity,the Bohai convergence zone moved northeastward.When northly winds flow over the northwest coast of Bohai Sea,the northwest part of the Bohai convergence zone moved southward due to the horizontal advection of northly wind,but the southeast part of the Bohai convergence zone continued to move northeastward due to the horizontal advection of northwestly wind and the force of ageostrophic winds and merged with the convergence zone caused by coastal front in north of Shandong Peninsula.It was the different moving directions of the two part of Bohai convergence zone that make the undulation in the convergence zone.When the Bohai convergence zone landed Shandong Peninsula,the severe snowstorm occurred.Taihang Mount played an important role in the meso-scale convergence zone by the formation of leeside depression,furthermore,the meso-scale convergence zone couples with the coastal front near the north coast of Shandong Peninsula and intensifies the snowstorms.

关 键 词：山东半岛 冷流暴雪 渤海辐合带 太行山背风低压 海岸锋 

分 类 号：P458.121[天文地球—大气科学及气象学]