阻塞高压建立的非线性机理探讨  

PRIMARY STUDY OF THE NONLINEAR MECHANISM ABOUT THE FORMATION OF BLOCKING HIGH

作　　者：郑祖光[1] 李秀玲[1] 刘莉红[1] 吴洪[1] 

机构地区：[1]中国气象局培训中心,北京100081

出　　处：《气象学报》2003年第5期513-525,共13页Acta Meteorologica Sinica

基　　金：国家自然科学基金项目 (4 9875 0 18)

摘　　要：文中建立了一个考虑斜压大气的超长波、长波与纬向气流相互作用的动力系统 ,其中把热力强迫和摩擦耗散作为外参数 ,采用相轨线图、流函数图和Poincar啨图综合分析的方法 ,绘制了外参数平面上的系统状态和环流型式的分布图。结果表明 :用Galerkin方法时 ,在一定范围内截谱阶数的增加对系统状态分布和环流型分布的影响不大 ,但在一定程度上增加了复杂性 ;加热分布的改变对系统影响很大 ;阻塞高压与环流振荡、经向度强烈发展有密切的联系 ,而天气波的发展有利于激发振荡。Blocking situation in Eurasia is a characteristic circulation of atmosphere, and its formation is a typical catastrophic phenomenon of circulation under the background With that the circulation meridionality grows strongly over Eurasia even to the Northern Hemisphere, and the circulation pattern frans formed from zonal through meridional, and then to blocking in turn. In this paper, the nonlinear theory and method are used to study this catastrophe and investigate the mechanism of blocking high. The main ideas are that: (1) The formation of blocking high links with the fluctuation and oscillation of circulation mechanism of the atmosphere system, so as to examine the evolvement of the system state, and the effect of the order of truncated spectrum and heating up distributing. (2) The formation of blocking high links with the atmosphere system's circulation changing from meridional to blocking pattern, so as to examine the evolvement of circulation, and the effect of the order of truncated spectrum and heating up distributing. The two aspects mentioned above are combined to comprehend the mechanism for formation of blocking high. The new research is explored: (1) Synoptic wave is add to the model (Lorenz, 1963) in which baroclinic atmosphere ultra-long wave and zonal flow interact, so a new model which contains ultra-long wave, zonal flow and synoptic wave is set up, and it is closed to the actual atmosphere. (2) By comparing and analyzing the spectral form of 14 variables which are already made with the new one of 22 variables that are set up by us, we examined the effect of order of truncated spectrum to system. (3) Considering the actual distributing of two oceans and two continents in the Northern Hemisphere, we chang the zonal homogeneous thermal field to zonal inhomogeneous thermal field containing two heat sources and two cold sources, for examining the effect of heating up distribution changing to system. (4) Figures among phase trajectory, stream function and Poincaré secti

关 键 词：动力系统 热力强迫 摩擦耗散 阻塞高压 GALERKIN方法 

分 类 号：P433[天文地球—大气科学及气象学]