Turbulence in Antarctic Circumpolar Current standing meanders.

This proposal is to study the role of turbulent mixing in the meridional overturning circulation of the Southern Ocean and the dynamics of the Antarctic Circumpolar Current (ACC). The project is motivated by the recent discovery of Southern Ocean regions of remarkably intense and widespread turbulence, an observation that defies current theoretical understanding of the circulation based on the assumption of little mixing in the ocean interior. The project is exciting because it will use innovative instrumentation to measure turbulent mixing in the deep Southern Ocean for the first time, to determine its dynamical causes and to assess its impact on the overturning circulation and the transport of the ACC. The focus of the project will be on observing and modelling the circulation and mixing in a standing meander of the ACC north of the Kerguelen Plateau, a dynamically important region of the current system. This novel way of looking at the ACC will provide important new insight into how the current interacts with bottom topography (a crucial issue for understanding what sets the ACC transport), the dynamical nature of the overturning circulation of the Southern Ocean and how this should be represented in ocean circulation and climate models.