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 projec-tion. 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. 1