BER launches Environmental System Science Program. Visit our new website under construction!

U.S. Department of Energy Office of Biological and Environmental Research

BER Research Highlights

Understanding Current and Eddy Contributions to Ocean Mixing
Published: July 13, 2017
Posted: January 26, 2018

Mixing is dominated by mean and eddy flow interactions; new mixing parameterizations are needed.

The Science
Ocean gyres and currents in the ocean interact to transport carbon and heat into the deep ocean. A simplified and idealized Antarctic Circumpolar Current flow is analyzed to understand what causes mixing by identifying mixing contributions by gyres, currents, and their interactions.

The Impact
Combined mixing by ocean gyres and currents dominate ocean mixing, suggesting that high resolution is necessary to compute the correct transport of carbon and heat into the deep ocean. Modifications are needed to existing mixing models using mixing suppression and critical layer theory; our diagnosed vertical variability and gyre-current interactions are key for improvement.

Transport of heat and carbon into the ocean from the atmosphere and melting of ice sheets by ocean flows is largely mediated by ocean mixing, quantified with a diffusivity. We diagnose mixing in an Idealized Circumpolar Current that approximates the Antarctic Circumpolar Current and Antarctic shelf break. We measure a reduced diffusivity over the shelf break, which is a mechanism that helps inhibit on-shelf mixing of ocean water with ice sheet cavities to help constrain the rate of land ice melting. Mixing is produced by the combined action of ocean gyres and currents, e.g., large eddies and the mean flow. We decompose the full diffusivity into its key mixing contributions by the eddy, mean, and residual (combined eddy-mean) flows. Results indicate that mixing is largely produced by interactions of the mean and eddy flows. Eddy and mean contributions are small as compared with the nonlinear residual. The diffusivity decomposition provides a path for improved understanding of ocean mixing. The importance of residual contributions of eddy-mean interactions indicates high resolution is key to resolving mixing. We find that existing diffusivity models require new and improved parameterization strategies.

Contacts (BER PM)
Dorothy Koch
Earth System Modeling Program

(PI Contact)
Phillip J. Wolfram
Los Alamos National Laboratory

The U.S. Department of Energy Office of Science, Biological and Environmental Research supported this research as part of the Accelerated Climate Modeling for Energy (ACME) project of the Earth System Modeling (ESM) program.

Wolfram, P., T.D. Ringler. "Quantifying Residual, Eddy, and Mean Flow Effects on Mixing in an Idealized Circumpolar Current." Journal of Physical Oceanography 47, 1897-1920 (2017). [DOI:10.1175/JPO-D-16-0101.1].
(Reference link)

Related Links
BER Highlight: Understanding Current and Eddy Contributions to Ocean Mixing

Topic Areas:

  • Research Area: Earth and Environmental Systems Modeling

Division: SC-33.1 Earth and Environmental Sciences Division, BER


BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

Mar 23, 2021
Molecular Connections from Plants to Fungi to Ants
Lipids transfer energy and serve as an inter-kingdom communication tool in leaf-cutter ants&rsqu [more...]

Mar 19, 2021
Microbes Use Ancient Metabolism to Cycle Phosphorus
Microbial cycling of phosphorus through reduction-oxidation reactions is older and more widespre [more...]

Feb 22, 2021
Warming Soil Means Stronger Microbe Networks
Soil warming leads to more complex, larger, and more connected networks of microbes in those soi [more...]

Jan 27, 2021
Labeling the Thale Cress Metabolites
New data pipeline identifies metabolites following heavy isotope labeling.

Analysis [more...]

Aug 31, 2020
Novel Bacterial Clade Reveals Origin of Form I Rubisco

  • All plant biomass is sourced from the carbon-fixing enzyme Rub [more...]

List all highlights (possible long download time)