Turning Ocean Mixing Upside Down
Name
Turning Ocean.pdf
Size
2.01 MB
Format
Adobe PDF
Checksum (MD5)
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Author(s)
McDougall, Trevor J.
Nikurashin, Maxim
Ferrari, Raffaele
Mashayekhi, Alireza
Campin, Jean-Michel
Date Issued
July 2016
Journal
Journal of Physical Oceanography
Publisher
American Meteorological Society
Citation
Ferrari, Raffaele et al. “Turning Ocean Mixing Upside Down.” Journal of Physical Oceanography 46.7 (2016): 2239–2261. © 2016 American Meteorological Society
Version
Final published version
Abstract
It is generally understood that small-scale mixing, such as is caused by breaking internal waves, drives upwelling of the densest ocean waters that sink to the ocean bottom at high latitudes. However, the observational evidence that the strong turbulent fluxes generated by small-scale mixing in the stratified ocean interior are more vigorous close to the ocean bottom boundary than above implies that small-scale mixing converts light waters into denser ones, thus driving a net sinking of abyssal waters. Using a combination of theoretical ideas and numerical models, it is argued that abyssal waters upwell along weakly stratified boundary layers, where small-scale mixing of density decreases to zero to satisfy the no density flux condition at the ocean bottom. The abyssal ocean meridional overturning circulation is the small residual of a large net sinking of waters, driven by small-scale mixing in the stratified interior above the bottom boundary layers, and a slightly larger net upwelling, driven by the decay of small-scale mixing in the boundary layers. The crucial importance of upwelling along boundary layers in closing the abyssal overturning circulation is the main finding of this work.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1175/jpo-d-15-0244.1
