Vertical transport by convection plumes: Modification by rotation

Convection, generated by destabilising buoyancy forcing, is a significant s ource of vertical mixing in the ocean and atmosphere. Ensembles of convecti ve elements or plumes transport buoyancy and tracers across the convective layer. Here we examine numerical simulations of turbulent convection to ide ntify the modifications to the vertical transports induced by strong rotati on (typical of deep ocean convection). We extract the typical convection pl umes from the numerical simulations using a conditional sampling compositin g technique. The plume budgets of mass, heat and momentum are then compared with an entraining plume model. In the presence of strong rotation the ver tical transports are significantly reduced by vigorous lateral mixing, whic h dilutes plume anomalies. This mixing is generated by the energetic cyclon ic vortices associated with the individual plumes and the interaction betwe en the many vortices in the plume ensemble. (C) 2001 Elsevier Science Ltd. All rights reserved.