Experimental Studies of a Polar Vortex I

A description is given of experiments carried out during 1949 and early 1950 that were designed to produce some phenomenon exhibiting effects of the resultant horizontal Coriolis force on a symmetrical vortex that results from the latitude variation of the Coriolis force. A circular cap of dense liquid at the base of a small hemispherical shell filled with liquid was forced to rotate about a vertical axis independently of the rate of rotation of the remaining fluid and containing vessels. Within the ranges of 20 to 150 r.p.m. for the vessel and 0 to 120 relative r.p.m. for the cap vortex, the center of mass of the polar cap never showed appreciable displacements away from the polar axis exept for a range of sufficiently high relative rotations when the vortex was anticyclonic in sense. Numerical checks are given with a simplified calculation in spherical coordinates of the torque equilibrium for the vortex as a whole.