Chapter 5.5 Deep convection

Publisher Summary This chapter reviews deep convection with emphasis on advances made during the World Ocean Circulation Experiment (WOCE) observing period. It describes some features of plumes, the convective mixing agents. The chapter also discusses two phenomena's associated with the convection. The first is the increase in the amplitude of temperature and salinity variability during convection observed in moored records. The second is the restratification of the density field following the cessation of convection. Most of the examples considered are from the Labrador Sea. A common relationship studied in deep convection region is that between heat loss from the surface and the resulting depth of convection. A simple way of estimating this is to integrate the buoyancy between the existing and final conditions and convert the integrated buoyancy loss to a heat loss. Restratification following convection also suggests a two-stage process. First is a rapid change lasting a month or so, possibly related to baroclinic eddies generated from baroclinic instability in a current at the edge of the convecting region, as suggested by Jones and Marshall. The second stage, a multi-month process, involves the slow decrease in the mixed water as it flows away from the region and its replacement lower densities by water inflowing from the boundaries.