Vertical transport by convection plumes: Modification by rotation

Convection, generated by destabilising buoyancy forcing, is a significant source of vertical mixing in the ocean and atmosphere. Ensembles of convective elements or plumes transport buoyancy and tracers across the convective layer. Here we examine numerical simulations of turbulent convection to identify the modifications to the vertical transports induced by strong rotation (typical of deep ocean convection). We extract the typical convection plumes from the numerical simulations using a conditional sampling compositing technique. The plume budgets of mass, heat and momentum are then compared with an entraining plume model. In the presence of strong rotation the vertical transports are significantly reduced by vigorous lateral mixing, which dilutes plume anomalies. This mixing is generated by the energetic cyclonic vortices associated with the individual plumes and the interaction between the many vortices in the plume ensemble. (C) 2001 Elsevier Science Ltd. All rights reserved.