涡旋Rossby波传播的不同特征

Different Characteristics of the Propagation of Vortex Rossby Waves

用一个柱坐标系涡度正压方程的半谱模式 ,实施了 4组试验 ,研究了不同初始扰动涡旋分布条件下 ,涡旋 Rossby波的传播特征问题。结果指出 :正值、负值相间的沿方向角二波分布的初始场 ,与只有正值涡旋的初始场相比 ,其后涡旋 Rossby波的传播有明显的差别 ,即前者向内传播的涡量比后者衰减得快 ,而且前者是单峰传播 。

Using a semi-spectral barotropic quasigeostrophic vorticity equation in the cylindrical coordinates,four experiments whose integration time is seven model hours are performed in order to study the propagation characteristics of vortex Rossby waves in different initial distributions of perturbation vorticity. Results show that propagation of vortex Rossy waves in an initial perturbation vorticity field of azimuthal wave-number 2(i.e positive alternating with negative) is obviously different from that in an intial field of only positive perturbation vorticity.The inward propagation vorticity decays more rapidly in the former case than in the latter case.And the inward propagation of vorticity exhibits a single peak form,but it shows a double peak form in the latter case.