Rossby波的下游效应引发我国高影响天气的分析被引量：30

Analysis of High Impact Weather Induced by the Downstream Effect of Rossby Waves

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摘要对近几年和历史上著名的深槽型暴雨及台风暴雨的分析表明,欧亚高空急流中Rossby波能量频散而产生的下游发展效应,对东亚高空槽的形成与发展、登陆台风的路径与长生命史有重要的影响。如果沿急流传播的Rossby波能量使110°E附近形成深厚的低压系统或使原有西风槽发展加深,天气尺度强迫产生强上升运动则非常有利于中国东部出现暴雨过程。而当欧亚中高纬Rossby波活动的下游效应导致在40°N附近东亚地区对流层中、高层形成闭合高压,同时有西太平洋台风或热带风暴登陆中国,受大尺度环流场引导气流的影响,台风往往取西行或西北行路径。如果同时来自海上的季风涌强烈,将延长台风环流系统的生命史,产生大范围致洪暴雨。目前业务上使用的全球数值预报模式对Rossby波列的下游发展效应有一定的中期预报能力,建议在日常业务预报中关注亚洲高空急流中Rossby波能量传播过程中大形势的突变与调整。Hovmller图分析方法,是分析Rossby波列下游发展效应的一个简单、直观和有效的工具,可应用于日常业务预报分析中。 Several heavy rain cases in recent years and in history were analyzed.The results show that the downstream development effects caused by the energy dispersal of Rossby waves through Asia jet have important impacts on the formation and development of high level troughs and the path and long life period of landed typhoons in East Asia.If the energy of stationary Rossby waves through Asia jet could form an intensive upper level trough or deepen a preexiting one near 110°E,the strong upward motion induced by large-scale forcing is in favor of the development of heavy rainfall in eastern China.When the downstream effects help developing an intense close anticyclone at high and middle levels of troposphere around 40°N in East Asia,and there is a typhoon or tropical storm from the West Pacific to China's Mainland,the landed tropical cyclone would tend to move towards west or northwest under the steering current around the anticyclonic edge.At the same time if the monsoon surges from the South China Sea are strong enough,the landed tropical cyclone will have a long journey over the land and produce heavy rainfall and floods. It was found that the global NWP models used in operation could,to some extent,forecast the down- stream development of Rossby waves at medium-range scale.Therefore,it is possible to monitor the abrupt changes or adjustment of large scale circulation caused by downstream effects at Asia jet in operational forecast process.The Hovmller diagram is a simple,intuitional,and effective tool for analyzing the Rossby wave downstream effects in forecast operation.

作者陶诗言卫捷梁丰张小玲

机构地区中国科学院大气物理研究所北京市气象局国家气象中心

出处《气象》 CSCD 北大核心 2010年第7期81-93,共13页 Meteorological Monthly

基金国家科技支撑计划(课题编号:2009BAC51B02) 北京市科技计划(课题编号:Z0006279040191)

关键词 ROSSBY波下游效应暴雨 Hovmller图 Rossby wave downstream development heavy rain Hovmller diagram

分类号 P433 [天文地球—大气科学及气象学]

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