偏心绕极涡旋的形成及其动力特征

THE FORMATION OF ECCENTRIC CIRCUMPOLAR VORTEX AND IT’S DYNAMIC PROPERTIES IN A 3-LAYER MODEL

  • 摘要: 本文利用一个描写对流层和平流层运动的三层模式,以最简化的非线性积分的方法,讨论了偏心绕极涡旋的存在及其与地形、热源的关系,并用瞬时作用的关系式讨论了偏心绕极祸旋的特性。文中得到了偏心绕极涡旋的一些动力特性,例如:β效应大于涡度平流;温度平流与涡度平流相比,在偏心涡旋中比在移动性长波中更为重要,说明这类涡旋具有更大的斜压性;在冬季由于它的存在,有可能使得平流层的强大扰动直接影响到对流层。在北半球,大地形和热源的偏心不对称分布,对纬围环流可以产生偏心扰动。在对流层用数值积分得到的第5天的结果,同模型实验及实况观测都比较相似。

     

    Abstract: In this paper the formation of eccentric circumpolar vortex in the troposphere and the stratophere is studied by integrating the simple non-linear dynamic equations in a 3-layer model.It is shown that the quasi-permarence of large-scale asymmetric circulations is produced by the orographic and thermal influences. The position and the intensisty of the tropospheric circumpolar vortex on the 5th day from the initial time is similar to the synoptic empirical results.The dynamical properties of the circumplar vortex are also discussed from the influence coefficents of the equations(11)-(14).

     

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