117223 final.pdf (4.21 MB)
Efficiency of turbulent mixing in the abyssal ocean circulation
journal contribution
posted on 2023-05-19, 05:40 authored by Mashayek, A, Salehipour, H, Bouffard, D, Caulfield, CP, Ferrari, R, Maxim NikurashinMaxim Nikurashin, Peltier, WR, Smyth, WDTurbulent mixing produced by breaking of internal waves plays an important role in setting the patterns of downwelling and upwelling of deep dense waters and thereby helps sustain the global deep ocean overturning circulation. A key parameter used to characterize turbulent mixing is its efficiency, defined here as the fraction of the energy available to turbulence that is invested in mixing. Efficiency is conventionally approximated by a constant value near one sixth. Here we show that efficiency varies significantly in the abyssal ocean and can be as large as approximately one third in density stratified regions near topographic features. Our results indicate that variations in efficiency exert a first-order control over the rate of overturning of the lower branch of the meridional overturning circulation.
Funding
Australian Research Council
History
Publication title
Geophysical Research LettersVolume
44Issue
12Pagination
6296-6306ISSN
0094-8276Department/School
Institute for Marine and Antarctic StudiesPublisher
Amer Geophysical UnionPlace of publication
2000 Florida Ave Nw, Washington, USA, Dc, 20009Rights statement
Copyright 2017 American Geophysical UnionRepository Status
- Restricted