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Widespread intense turbulent mixing in the Southern Ocean
Alberto C Naveira Garabato1, Kurt L Polzin, Brian A King
1School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK. a.naveira-garabato@uea.ac.uk
Science (New York, N.Y.)
|January 13, 2004
Summary
Turbulent mixing in the Southern Ocean is intense and widespread over rough topography. This process is crucial for ocean circulation and requires inclusion in global ocean models.
Area of Science:
- Oceanography
- Fluid Dynamics
- Geophysics
Background:
- Internal wave velocity fluctuations are key indicators of ocean mixing.
- Turbulent mixing plays a vital role in vertical ocean transport and heat distribution.
- The Southern Ocean's complex bathymetry influences oceanographic processes.
Purpose of the Study:
- To quantify the intensity and spatial extent of turbulent mixing over rough topography in the Southern Ocean.
- To assess the significance of this mixing for ocean circulation and tracer transport.
- To highlight the necessity of incorporating these findings into numerical ocean models.
Main Methods:
- Analysis of internal wave velocity fluctuations.
- Observation of mixing rates over large-scale bathymetric features.
- Geospatial mapping of mixing intensity and extent.
Main Results:
- Enhanced turbulent mixing rates, 10 to 1000 times background levels, are widespread over rough topography.
- This intense mixing occurs at depths greater than 500-1000 meters.
- The affected area spans 2000-3000 kilometers.
Conclusions:
- Turbulent mixing over Southern Ocean topography is a critical driver of upward water transport.
- This process is essential for closing the ocean's meridional overturning circulation.
- Accurate representation of this mixing is imperative for global ocean circulation and biogeochemical tracer simulations.
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