论文标题
球形壳中的孤立磁性rossby波
Solitary magnetostrophic Rossby waves in spherical shells
论文作者
论文摘要
研究了磁性状态中的有限振幅水力rossby波。我们考虑慢速模式，该模式沿相反的方向传播到流体动力或快速模式，在存在环形磁场和Zonal流动的情况下，通过准斑块模型用于厚球形壳。使用还原性扰动方法渐近地推导了弱非线性，长波是渐近地得出的。发现一阶的问题是遵守二阶颂歌，从而导致Malkus场的超几何方程和电气线场的汇合HEUN方程，并且当波速接近平均流量时，它是非词性的。研究了其对不同基本状态的中性，非发挥征出的，我们发现该进化是由Korteweg-de Vries方程描述的。这意味着非线性慢波形成孤子和孤立波。这些可能采用连贯的涡流，例如单个反气旋。我们推测抗周期与地球流体核心以及最新的发电机DN中看到的不对称回旋的关系。
Finite-amplitude hydromagnetic Rossby waves in the magnetostrophic regime are studied. We consider the slow mode, which travels in the opposite direction to the hydrodynamic or fast mode, in the presence of a toroidal magnetic field and zonal flow by means of quasi-geostrophic models for thick spherical shells. The weakly-nonlinear, long waves are derived asymptotically using a reductive perturbation method. The problem at the first order is found to obey a second-order ODE, leading to a hypergeometric equation for a Malkus field and a confluent Heun equation for an electrical-wire field, and is nonsingular when the wave speed approaches the mean flow. Investigating its neutral, nonsingular eigensolutions for different basic states, we find the evolution is described by the Korteweg-de Vries equation. This implies that the nonlinear slow wave forms solitons and solitary waves. These may take the form of a coherent eddy, such as a single anticyclone. We speculate on the relation of the anti-cyclone to the asymmetric gyre seen in Earth's fluid core, and in state-of-the-art dynamo DNS.
