Heat and mass transport in geostrophic horizontal convection with surface wind stress

Abstract

Direct Numerical Simulations are conducted to investigate heat and mass transport of flow with buoyancy forcing and surface wind stress. We use a re-entrant channel model with thermal and mechanical forcing similar to the Southern Ocean, with increasing surface wind stress. The model fully characterises convection and turbulence in the fluid. The presence of convection appears to significantly enhance the buoyancy-driven overturning, resulting in an overturning cell which dominates the flow field compared with a relatively shallow and weak wind-driven cell. The vertical heat transport also indicates that the majority of vertical advective heat transport occurs in the convective zone, with strong upwelling of heat in this region. These results indicate that the presence of convection significantly enhances the impact of buoyancy forcing in driving mass and heat transport.