【作者】 李春虎；

【导师】 罗哲贤；

【作者基本信息】 南京信息工程大学 ， 气象学， 2011， 博士

【摘要】 应用自动站、多普勒雷达、卫星云图、常规天气图和NCEP/NCAR 1°×1°的网格点资料,分析了2006年7月27日山东半岛东部致灾暴雨中的自组织过程；探索了热带低压倒槽、高空西风槽和副热带高压等天气尺度环境场对云团自组织的作用。用一个准地转正压涡度方程模式,数值研究了随机分布的多个小尺度涡对涡旋自组织的影响。研究了负排熵指数的自组织。在多个例的基础上,提炼了自组织发生发展的若干预测判据,并用这些判据开展了暴雨事件的预测应用研究,取得了好的效果。主要进展如下：(1)发现局地暴雨中云团自组织存在阶段性特征,即一次局地暴雨过程并不是一次云团的自组织完成的,而是多次自组织完成的。如在2006年7月27日山东半岛东部致灾暴雨过程中,可清楚识别出4次云团的自组织。(2)发现不同尺度系统的相互作用对自组织有重要影响。这里,不同尺度系统既包括比中尺度云团大的天气尺度系统,也包括比中尺度云团小的小尺度的系统。前者包括高空西风槽、热带低压倒槽和副热带高压,它们提供了云团自组织的环境场条件;后者包括随机分布的小尺度的系统,它们提供了云团自组织的微环境场条件。以往同类研究中、小尺度系统系人为给定的；本文中、小尺度系统系随机生成的,减少了人为性。随机分布小尺度涡的引进,可导致自组织终态的差异。(3)把自组织理论和耗散结构理论的工作思路结合起来,结果显示,负排熵指数自组织的区域清楚地反映了暴雨的落区,可为对流性暴雨中心落区预报提供有益的信息。(4)在分析2000-2007年夏季卫星云图资料的基础上,发现山东省区域性或大范围暴雨天气过程中,产生暴雨的中尺度云团的发展演变经历了由无组织到有组织、由不规则云形到规则云形的过程。得到了云团的自组织的若干判据,并在业务中初步应用。更多还原

【Abstract】 This paper analyzes a hazard heavy rain occurred on July 27 2006 in eastern part of Shandong Peninsula by using automatic stations, Doppler radar, satellite images, conventional weather maps and NCEP/NCAR 1°×1°grid point data, and explores effects of the environmental field on the synoptic scale on clouds self-organization such as tropical low pressure trough, high-altitude westerly trough and the subtropical high and so on. Numerical study of influences of multiple randomly distributed small-scale vortexes on the vortex self-organization has been carried on with a quasi-geostrophic barotropic vorticity equation model. Also self-organizations of negative removal entropy index have been studied in this paper. On the basis of many cases, a number of predicted criteria of occurrence and development of self-organization have refined, which are used to study prediction of heavy rain events, and achieve good results.Major developments are as follows:(1) Stage characteristics of self-organization of clouds in local heavy rain are found, which is one local rainstorm don’t complete by only one but several self-organization. As in a hazard heavy rain process, on July 27 2006 in eastern part of Shandong Peninsula,4 clouds self-organizing process could be identified clearly.(2) It is found that the interaction of different scale systems have a major impact on self-organization. Systems at different scales include synoptic-scale systems larger than mesoscale clouds and small-scale systems smaller than mesoscale clouds. Synoptic-scale systems, the former, provide environment field conditions of self-organization including high-altitude westerly trough, tropical low pressure trough and the subtropical high. The latter include small-scale randomly distributed systems, and they provide micro-environment field conditions of self-organization. Although small-scale systems were artificially given in previous similar studies, which is random generated in this research in order to reduce the artificiality. The introduction of randomly distributed small-scale vortex could lead to differences in final state of self-organization.(3) Making the self-organization theory and dissipative structures theory together into work ideas shows the convergence of negative removal entropy index of self-organization reflects the rainstorm falling area clearly, and provides useful information to falling center forecast of convective rain.(4) On the basis of analyzing summer satellite image data from 2000 to 2007, it is found that the evolution of mesoscale clouds which can cause rainstorm experiences processes from non-organized to organized, from irregular shape to regular, and obtained a number of criteria of self-organization clouds, which have been initially applied in operational applications.更多还原