Deep convection is a process in which the mesoscale ocean circulation and atmospheric forcing work together to weaken the ambient stratification and to cause surface waters to sink to great depths with large vertical velocities. This process plays an important role in bottom and intermediate water formation and ultimately in the large-scale thermohaline circulation, which in turn plays a central part in determining global climate. Until now, our understanding of deep convection was based on observations and models of the mesoscale effects of deep convection. With recent advances in numerical modeling techniques and instrumentation, we have begun to study the role of the mixing elements: the deep, penetrative convective plumes shown in Figure 1. These plumes are turbulent, have a large vertical scale and have attributes that are unique for turbulent plumes: they are affected by the nonlinear relationship between temperature and pressure in the density of sea water and by rotation. Numerical model results, such as those shown here, clearly demonstrate that turbulent mixing affects climate-related processes; that is, deep convective plumes are evidence that small-scale features affect the large-scale circulation.