东亚地区南北两个风暴源地中风暴的结构和动力学差异  

Differences in storm structure and internal dynamics of the two storm source regions over East Asia

作　　者：赵远冰 梁湘三[1,2] 朱伟军 ZHAO Yuanbing;LIANG Xiangsan;ZHU Weijun(School of Atmospheric Sciences,Nanjing University of Information Science and Technology,Nanjing 210044,China;School of Marine Sciences,Nanjing University of Information Science and Technology,Nanj ing 2100441 China)

机构地区：[1]南京信息工程大学大气科学学院,南京210044 [2]南京信息工程大学海洋科学学院,南京210044

出　　处：《气象学报》2018年第5期663-679,共17页Acta Meteorologica Sinica

基　　金：国家自然科学基金(41576088;41575070;41705024);2015江苏省创新团队项目;2015江苏省特聘教授项目;国家行业专项-全球变化和海气相互作用(GASI-IPOVAI-06)

摘　　要：基于欧洲中心中期天气预报再分析资料(ERA-40),使用涡旋追踪和合成技术、多尺度子空间变换以及局地多尺度能量分析方法研究了东亚地区南北两个风暴源地中风暴的差异。结果发现,南、北两个源地风暴在结构上和内部动力过程上均存在着显著不同。南支源地(40°N以南)风暴底层比高层强,与线性斜压模式中的最不稳定模态结构相似;而北支源地(40°N以北)风暴则正好相反,与下游发展理论所描述的斜压波结构相似。并且发现,南支源地风暴的非地转风场比北支源地风暴的强。能量学诊断结果显示,南支源地风暴的能量源除了斜压不稳定外,有很大一部分来自正压不稳定,而北支源地风暴中则是存在弱的动能逆尺度传输。此外,南支源地风暴的浮力转换和非绝热做功均比北支源地风暴的强,其主要原因是南支源地风暴的垂直运动更强,风暴中的水汽更加充足。Using a new localized multi-scale energetics analysis method and a feature tracking and compositing technique, this study investigates the structure and internal dynamics of the storms over the two storm source regions over East Asia based on data from the European Centre for Medium-Range Weather Forecasts ReAnalysis （ERA-40）. It is found that the two regions are significantly different in both storm structure and internal dynamics. Storms in the south exhibit the bottom-trapped feature with perturbations intensified at the bottom, similar to the most unstable mode in the linear baroclinic model, whereas storms in the north have the largest amplitude in the upper troposphere, just as that described in terms of downstream development. Besides, it is found that storms in the south have stronger ageostrophic winds. Localized multi-scale energetics analysis result shows that they experience both baroclinic instability and barotropic instability. For storms in the north, however, barotropic instability is absent. We find that the buoyancy conversion and diabatic effect are much stronger in the south, which can be at- tributed to the stronger vertical motion and more vapor content there.

关 键 词：中纬度气旋 风暴轴 特征追踪 多尺度能量学 斜压/正压不稳定 

分 类 号：P443[天文地球—大气科学及气象学]