A321 f-平面浅水系における軸対称孤立渦の安定性(A-32 大気の流れ(2),一般講演)

概要

論文の詳細を見る
The stability of an isolated axisymmetric vortex of a Gaussian shape in a circular region of a f-plane shallow water system is examined. Numerical results of linear stability analyses and nonlinear time evolutions are presented. These calculations are executed using the spectral method by Ishioka, which expands dependent valuables by Jacobi polynomials in the radial direction. The results of linear stability analyses are consistent with those for an isolated axisymmetric vortex patch in an infinite domain by Ford. Our linear analyses reveal not only that the disturbance of the circumferential wave number 2 is the most unstable in a wide range of Colioris parameter f and Froude number Fr but that the growth rate of the disturbance is maximized with Fr〜O(1) when f is fixed. The results of nonlinear time evolutions show that the vortex splits into two if it is linearly unstable. These non-linear results are consistent with those by Ford and Chan et al.
日本流体力学会の論文
2004-08-09