一次东北冷涡背景下MCS过程多尺度能量相互作用研究
投稿时间:2019-11-09  修订日期:2020-02-05  点此下载全文
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作者单位E-mail
沈新勇 南京信息工程大学 shenxy@nuist.edu.cn 
张弛 南京信息工程大学  
肖云清 银川市气象局  
沙莎 上海海洋中心气象台  
王林 南京信息工程大学  
李小凡 浙江大学  
基金项目:国家自然科学基金项目(面上项目,重点项目,重大项目);中国科学院重大资助项目
中文摘要:本文采用WRF模式对东北冷涡背景下MCS过程进行模拟,利用Barnes滤波将模式数据分解为三个尺度,分别代入相应的能量方程中进行计算,从能量角度研究MCS发展过程,多尺度系统能量相互转化,以及动能与降水的联系。研究表明:在此次过程中,各尺度之间都有位能向动能的大量转化,为系统发展提供能量。在对流单体发展到MCS成形前,中低层天气尺度动能减少,天气尺度动能向β中小尺度动能转换,促进对流单体的发展;高层天气尺度动能增强,对应高空急流增强,促进对流系统发展;β中小尺度系统在中层对α中尺度系统有动能输送,促进MCS形成。在MCS形成和发展阶段,各尺度位能向α中尺度和β中小尺度动能转化达到最大。在MCS减弱阶段,天气尺度系统和α中尺度系统在中高层对β中小尺度系统有一定的抑制作用,使β中小尺度系统发展减弱。此次过程中β中小尺度系统是降水的直接成因,动能变化的正值中心对应大的降水中心。
中文关键词:东北冷涡  MCS  多尺度  能量  相互作用
 
Multi-scale energy interaction study in MCS process under a Northeast Cold Vortex
Abstract:The MCS process under the background of Northeast Cold Vortex is simulated with WRF model. Barnes filter is used to decompose the model data into three scales, which are substituted into the corresponding energy equation for calculation. The development process of MCS, energy conversion of multi-scale system and the relationship between kinetic energy and precipitation are studied from the perspective of energy. The research shows that in this process, there is a large amount of potential energy to kinetic energy, which provides energy for the development of the system. During the development of convection cell to MCS forming, the large scale kinetic energy in the middle and lower layers decreased, and the large scale kinetic energy changed to the small and medium scale kinetic energy, which promoted the development of convective monomer. The enhancement of large-scale kinetic energy in the upper layer corresponds to the enhancement of upper jet stream and promotes the development of convection system. The β mesoscale system has kinetic energy transfer to the α mesoscale system in the middle layer, which promotes the formation of MCS. During the formation and development of MCS, the conversion of potential energy at various scales to kinetic energy at α mesoscale and β mesoscale reached its maximum. During the MCS weakening phase, the large scale system and the α mesoscale system have a certain inhibitory effect on the β mesoscale system at the middle and upper levels, which weakens the development of the β mesoscale system. In this process, the β mesoscale scale system is the direct cause of precipitation, and the positive center of kinetic energy change corresponds to the large precipitation center.
keywords:Northeast Cold Vortex  MCS  Multi-scale  Energy  Interaction
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