Southern Ocean Dynamics - Turbulence & Mixing
Uncertainty about the rates and mechanisms by which small-scale turbulent dissipation and mixing occur in the ocean remains an important outstanding issue in the field, and many unanswered questions remain such as what is the global landscape of mixing rates in space and time, what processes are responsible for setting that distribution, what are the implications of "patchy" mixing for global circulation patterns, and what are the ways in which the rate of mixing is conditioned by the larger scale flow. These questions are especially critical in the Southern Ocean, where mixing drives important water mass transformations that act to close the global overturning circulation, and as such controls the ocean's north-south transport of heat, carbon and other important climate variables.
Through large international field campaigns, the Southern Ocean Finestructure (SOFine) and Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean (DIMES) experiments, we have made the first-ever dedicated measurements of small-scale turbulence in various Southern Ocean regimes. By doing so, we have provided rare in situ measurements of ocean turbulence that are critically important for informing the representation of ocean mixing rates in ocean and climate models, provided direct observational confirmation of the importance of internal waves and the turbulence they generate to the larger-scale Southern Ocean energy and momentum budgets, and shed important light on the critical processes that control the “patchiness” of the ocean mixing rate distribution observed. Our continued work aims to better understand the processes controlling the distribution of turbulence and mixing in the Southern Ocean by better understanding the interactions between turbulence and the local large-scale, mesoscale and internal wave fields. By contributing to a process-based understanding of mixing geography, this work is critical to the on-going design of parameterizations of turbulent mixing that are urgently needed in ocean and climate models.
Select papers & Presentations:
In the News: