動径基底函数を用いた球面螺旋浅水波モデル

Abstract

A shallow-water model on the sphere on spherical helix nodes has been developed using radial basis functions. A simple non-iterative algorithm is available to generate quasi-uniform nodes along a spherical helix on the sphere. The proposed model is verified with the experiments for steady state nonlinear geostrophic flows and for the zonal flow over an isolated mountain from the standard test suite. The model on the spherical helix nodes is found to be as accurate as that on the minimum energy nodes used in the previous studies. In the steady-state tests, the spherical helix model often outperformed the minimum energy model. In the more realistic test cases, the differences are obscure. The shallow-water model using radial basis functions on spherical helix nodes is a viable approach because of efficient node generation and spectral accuracy.