Planetary waves in a symmetrical polar basin

The problem of low frequency zonal vorticity waves in a symmetric polar basin is formulated in a plane projection tangent to the sphere at the pole. Eigensolutions are found when only first order curvature effects are retained in the plane of projection. Comparison with the results of Longuet-Higgins (1964b) shows that such an approximation provides a reliable analogue, applicable to the polar regions, of the mid-latitude beta-plane.