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A Mechanism for Local Dissipation of Internal Tides Generated at Rough Topography
Citation
Nikurashin, M and Legg, S, A Mechanism for Local Dissipation of Internal Tides Generated at Rough Topography, Journal of Physical Oceanography, 41, (February) pp. 378-395. ISSN 0022-3670 (2011) [Refereed Article]
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Copyright Statement
© Copyright 2011 AMS
DOI: doi:10.1175/2010JPO4522.1
Abstract
Fine- and micro-structure observations indicate that turbulent mixing is enhanced within O(1) km above
rough topography. Enhanced mixing is associated with internal wave breaking and, in many regions of the
ocean, has been linked to the breaking and dissipation of internal tides. The generation and dissipation of
internal tides are explored in this study using a high-resolution two-dimensional nonhydrostatic numerical
model, which explicitly resolves the instabilities leading to wave breaking, configured in an idealized domain
with a realistic multiscale topography and flow characteristics. The control simulation, chosen to represent the
Brazil Basin region, produces a vertical profile of energy dissipation and temporal characteristics of finescale
motions that are consistent with observations. Results suggest that a significant fraction of mixing in the
bottom O(1) km of the ocean is sustained by the transfer of energy from the large-scale internal tides to
smaller-scale internal waves by nonlinear wavewave interactions. The time scale of the energy transfer to
the smaller scales is estimated to be on the order of a few days. A suite of sensitivity experiments is carried
out to examine the dependence of the energy transfer time scale and energy dissipation on topographic
roughness, tidal amplitude, and Coriolis frequency parameters. Implications for tidal mixing parameterizations
are discussed.
Item Details
| Item Type: | Refereed Article |
|---|---|
| Keywords: | mixing, internal tides, wave breaking, mixing parameterization, wave-wave interactions, rough topography |
| Research Division: | Earth Sciences |
| Research Group: | Oceanography |
| Research Field: | Physical Oceanography |
| Objective Division: | Environment |
| Objective Group: | Climate and Climate Change |
| Objective Field: | Climate Change Models |
| UTAS Author: | Nikurashin, M (Dr Maxim Nikurashin) |
| ID Code: | 79719 |
| Year Published: | 2011 |
| Web of Science® Times Cited: | 51 |
| Deposited By: | IMAS Research and Education Centre |
| Deposited On: | 2012-10-01 |
| Last Modified: | 2012-11-26 |
| Downloads: | 0 |
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