BREAKDOWN OF LINE PLUMES IN TURBULENT ENVIRONMENTS

The results of a laboratory experiment that was designed to investigate the effects of background turbulence on turbulent line plumes are presented. This work was motivated by its potential application to winter polar leads, in which refreezing of open water induces buoyant plumes that descend through the upper ocean mixed layer. Scaling arguments are advanced to delineate different types of interactions that may occur between line plumes and background turbulence, and some of these arguments are verified using laboratory experiments. It is shown that turbulent line plumes can be completely destroyed by the background turbulence when the convective velocity of the plume w* is less than about 1.6u(0), where u(0), is the background turbulent intensity. Possible applications of the present laboratory results to lead-related oceanic situations are also discussed.