Non-Hydrostatic Ocean Modelling for Studies of Open-Ocean Deep Convection

Abstract It is argued that non-hydrostatic effects are important in the dynamics of open-ocean deep convection on horizontal scales ~ 1 km, typical of sinking plumes. The formulation and numerical implementation of a non-hydrostatic ocean model appropriate for the explicit representation of plume-scale dynamics is described. The model is used to study the spin-up, through convective overturning induced by surface cooling, and subsequent geostrophic adjustment of a baroclinic vortex with a horizontal scale of the order of the Rossby radius of deformation.