Acta Scientiarum Naturalium Universitatis Pekinensis

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Vortex Dynamics on Synoptic Maps

LIU Gang1, 2, LIU Shida1, LIU Feng1, 3, LIU Shikuo1   

  • Received:2006-03-22 Online:2007-01-20 Published:2007-01-20

天气图上的涡旋动力学

刘刚1,2, 刘式达1, 刘峰1, 3, 刘式适1   

Abstract: There are many vortex patterns on synoptic maps. It is shown from this thesis that flow fields on synoptic maps can be decomposed into rotation and deformation fields. Geostrophic non-frictional cyclone and anticyclone vortex patterns are closed circulations around the center point, streamlines of frictional cyclone and anticyclone patterns have spiral forms around the focus point. Saddle fields have four vortex centers (two cyclones and two anticyclones) and a saddle point. Blocking high pressure and cut-off low pressure patterns consist of a vortex center and a saddle point. From the above results, we can clearly understand the actual atmospheric vortex dynamics and its mechanisms of formation.

Key words: atmospheric flow field, vortex, decomposition of velocity field, singular point

摘要: 天气图上有许多种涡旋型式。本文说明了天气图上的流场可以分解为旋转场和变形场:地转无摩擦的气旋、反气旋的涡旋型式是围绕中心点的闭合环流;考虑摩擦的气旋、反气旋的流型是围绕焦点的螺旋型式;鞍型场有4个涡旋中心点(2个气旋和2个反气旋)与1个鞍点;阻塞高压和切断低压由1个涡旋中心点与1个鞍点组成。从以上结果可以清楚地了解实际大气涡旋形态的动力和形成机制。

关键词: 大气流场, 涡旋, 速度场分解, 奇点

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