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Internal tide generation by abyssal hills using analytical theory
Citation
Melet, A and Nikurashin, M and Muller, C and Falahat, S and Nycander, J and Timko, J and Arbic, BK and Goff, JA, Internal tide generation by abyssal hills using analytical theory, Journal of Geophysical Research: Oceans, 118, (11) pp. 6303-6318. ISSN 2169-9275 (2013) [Refereed Article]
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Copyright Statement
Copyright 2013 American Geophysical Union
Abstract
Internal tide driven mixing plays a key role in sustaining the deep ocean stratification
and meridional overturning circulation. Internal tides can be generated by topographic
horizontal scales ranging from hundreds of meters to tens of kilometers. State of the art
topographic products barely resolve scales smaller than ~10 km in the deep ocean. On these
scales abyssal hills dominate ocean floor roughness. The impact of abyssal hill roughness on
internal-tide generation is evaluated in this study. The conversion of M2 barotropic to
baroclinic tidal energy is calculated based on linear wave theory both in real and spectral
space using the Shuttle Radar Topography Mission SRTM30_PLUS bathymetric product at
1/120 degree resolution with and without the addition of synthetic abyssal hill roughness. Internal
tide generation by abyssal hills integrates to 0.1 TW globally or 0.03 TW when the energy
flux is empirically corrected for supercritical slope (i.e., ~10% of the energy flux due to
larger topographic scales resolved in standard products in both cases). The abyssal hill
driven energy conversion is dominated by mid-ocean ridges, where abyssal hill roughness is
large. Focusing on two regions located over the Mid-Atlantic Ridge and the East Pacific
Rise, it is shown that regionally linear theory predicts an increase of the energy flux due to
abyssal hills of up to 100% or 60% when an empirical correction for supercritical slopes is
attempted. Therefore, abyssal hills, unresolved in state of the art topographic products, can
have a strong impact on internal tide generation, especially over mid-ocean ridges.
Item Details
| Item Type: | Refereed Article |
|---|---|
| Keywords: | internal waves; tides; mixing; rough topography; abyssal hills |
| Research Division: | Earth Sciences |
| Research Group: | Oceanography |
| Research Field: | Physical oceanography |
| Objective Division: | Environmental Policy, Climate Change and Natural Hazards |
| Objective Group: | Understanding climate change |
| Objective Field: | Climate change models |
| UTAS Author: | Nikurashin, M (Dr Maxim Nikurashin) |
| ID Code: | 87945 |
| Year Published: | 2013 |
| Web of Science® Times Cited: | 41 |
| Deposited By: | IMAS Research and Education Centre |
| Deposited On: | 2013-12-18 |
| Last Modified: | 2022-08-30 |
| Downloads: | 130 View Download Statistics |
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