Inertial Taylor columns on a beta plane

Abstract

The effect of variable Coriolis parameter on the formation of inertial Taylor columns is determined for the case of a two-layer fluid with moderate stratification. Analytic solutions of the inertial, quasi-geostrophic, β-plane equations are obtained. As a special case, sohtions corresponding to a single-layer, homo-geneous fluid are also obtained. When both layer velocities are retrograde (westward), the effect of β is to limit the horizontal extent of the disturbance due to the bump. When both layer velocities are prograde (eastward), an extensive meandering wake is found downstream of the bump. Associated with this wake can be large stationary cyclonic and anti-cyclonic eddies. The meander amplitudes in the two layers are typically nearly the same. I n both the retrograde and prograde cases, the strength of the disturbance to the flow above the bump is less in the upper layer compared with the lower, indicating an attenuation in the vertical due to stratification. For a counter-flow situation, the solutions are complicated by the possibility of a stationary baroclinic wave, one that would exist even for β = 0. In all the situations in which a meandering wake is formed, there is a wave-drag force on the bump. Some laboratory experiments corres- ponding to the single-layer solutions are described.