2022 Gordon Research Conference on Ocean Mixing: The Impact of Ocean Mixing on the Earth, Ocean and Atmosphere Systems, Climate and Society

This project provides partial support for the 2022 Gordon Research Conference and Gordon Research Seminar on Ocean Mixing. Turbulent mixing results from complex and chaotic motions that span a large range of spatial and temporal scales. As such, it is particularly challenging to measure and model, yet it has vast and important consequences.

In the ocean, turbulent mixing controls transport of heat, freshwater, dissolved gasses, and pollutants. It is crucial for ocean biology because it both determines the flow field for the smallest plankton, and it sets large-scale gradients of nutrient availability. It is also central to understanding the energetics of the ocean and reducing the uncertainties in global circulation and climate models: recent work has shown that the spatial and temporal non-homogeneity in deep-ocean mixing may play a critical role in climate; understanding the physics that drives the distribution of deep-ocean mixing intensity is critical.

Yet even after a half a century of efforts to understand its global distribution, observations are still sparse; a variety of direct and indirect methods are still needed to characterize the dynamical processes that lead to turbulence, and inferences of mixing from larger scale budgets. As such, the physics of ocean mixing is actively studied using a variety of observational techniques (direct measure of velocity and temperature fluctuations at the smallest (mm) scales, inferences from large-scale turbulent overturns, observations of net mixing by purposeful dye release) numerical and theoretical approaches, as well as laboratory experiments.

Finally, the consequences of mixing for larger scale climate models (which do not directly resolve mixing) are addressed by turning dynamical insights of the previously mentioned work into practical parameterizations. As a concrete example, using different mixing schemes in numerical climate models changes predicted tropical ocean temperatures by more than a degree and predicted sea level rise by more than 30 cm.

Mixing is one of the greatest sources of uncertainty plaguing today’s models with impact of great societal relevance. A regularly held GRC on Ocean Mixing provides a needed forum to improve the broader community’s understanding of turbulent mixing in the ocean, and with it a variety of deep and broad implications for everything from climate change to global nutrient patterns that underlie our fisheries.

The GRC format encourages precisely the sort of interdisciplinary thinking and collaboration that is so vital to addressing these societal issues. This GRC, in particular, helps our scientific community be the most vibrant & inclusive it can be. The ocean mixing has historically suffered from poor diversity, which, while improved in recent years, still needs an influx of new people, a broadening of ties amongst domestic and international collaborators, and increased interdisciplinary interactions.

NSF support will explicitly be used to expand the demographic, professional and geographic diversity of participants by supporting attendance of under-represented and under-resourced groups who stand to benefit from the intellectual environment and networking opportunities of the GRC format.

The purpose and scope of this Gordon Research Conference is to provide a forum for discussion of the rapidly evolving field of ocean mixing. Emphasis is threefold: observations of mixing in the world, new insights into dynamics that control mixing rates, and impacts of mixing on regional and global circulation and budgets. The latter two include development of parameterizations to turn dynamical insights into useful things to include in regional models and global numerical climate models.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.