---
_id: '9134'
abstract:
- lang: eng
  text: Several studies have shown the existence of a critical latitude where the
    dissipation of internal tides is strongly enhanced. Internal tides are internal
    waves generated by barotropic tidal currents impinging rough topography at the
    seafloor. Their dissipation and concomitant diapycnal mixing are believed to be
    important for water masses and the large‐scale ocean circulation. The purpose
    of this study is to clarify the physical processes at the origin of this strong
    latitudinal dependence of tidal energy dissipation. We find that different mechanisms
    are involved equatorward and poleward of the critical latitude. Triadic resonant
    instabilities are responsible for the dissipation of internal tides equatorward
    of the critical latitude. In particular, a dominant triad involving the primary
    internal tide and near‐inertial waves is key. At the critical latitude, the peak
    of energy dissipation is explained by both increased instability growth rates,
    and smaller scales of secondary waves thus more prone to break and dissipate their
    energy. Surprisingly, poleward of the critical latitude, the generation of evanescent
    waves appears to be crucial. Triadic instabilities have been widely studied, but
    the transfer of energy to evanescent waves has received comparatively little attention.
    Our work suggests that the nonlinear transfer of energy from the internal tide
    to evanescent waves (corresponding to the 2f‐pump mechanism described by Young
    et al., 2008, https://doi.org/10.1017/S0022112008001742) is an efficient mechanism
    to dissipate internal tide energy near and poleward of the critical latitude.
    The theoretical results are confirmed in idealized high‐resolution numerical simulations
    of a barotropic M2 tide impinging sinusoidal topography in a linearly stratified
    fluid.
article_processing_charge: No
article_type: original
author:
- first_name: O.
  full_name: Richet, O.
  last_name: Richet
- first_name: J.-M.
  full_name: Chomaz, J.-M.
  last_name: Chomaz
- first_name: Caroline J
  full_name: Muller, Caroline J
  id: f978ccb0-3f7f-11eb-b193-b0e2bd13182b
  last_name: Muller
  orcid: 0000-0001-5836-5350
citation:
  ama: 'Richet O, Chomaz J-M, Muller CJ. Internal tide dissipation at topography:
    Triadic resonant instability equatorward and evanescent waves poleward of the
    critical latitude. <i>Journal of Geophysical Research: Oceans</i>. 2018;123(9):6136-6155.
    doi:<a href="https://doi.org/10.1029/2017jc013591">10.1029/2017jc013591</a>'
  apa: 'Richet, O., Chomaz, J.-M., &#38; Muller, C. J. (2018). Internal tide dissipation
    at topography: Triadic resonant instability equatorward and evanescent waves poleward
    of the critical latitude. <i>Journal of Geophysical Research: Oceans</i>. American
    Geophysical Union. <a href="https://doi.org/10.1029/2017jc013591">https://doi.org/10.1029/2017jc013591</a>'
  chicago: 'Richet, O., J.-M. Chomaz, and Caroline J Muller. “Internal Tide Dissipation
    at Topography: Triadic Resonant Instability Equatorward and Evanescent Waves Poleward
    of the Critical Latitude.” <i>Journal of Geophysical Research: Oceans</i>. American
    Geophysical Union, 2018. <a href="https://doi.org/10.1029/2017jc013591">https://doi.org/10.1029/2017jc013591</a>.'
  ieee: 'O. Richet, J.-M. Chomaz, and C. J. Muller, “Internal tide dissipation at
    topography: Triadic resonant instability equatorward and evanescent waves poleward
    of the critical latitude,” <i>Journal of Geophysical Research: Oceans</i>, vol.
    123, no. 9. American Geophysical Union, pp. 6136–6155, 2018.'
  ista: 'Richet O, Chomaz J-M, Muller CJ. 2018. Internal tide dissipation at topography:
    Triadic resonant instability equatorward and evanescent waves poleward of the
    critical latitude. Journal of Geophysical Research: Oceans. 123(9), 6136–6155.'
  mla: 'Richet, O., et al. “Internal Tide Dissipation at Topography: Triadic Resonant
    Instability Equatorward and Evanescent Waves Poleward of the Critical Latitude.”
    <i>Journal of Geophysical Research: Oceans</i>, vol. 123, no. 9, American Geophysical
    Union, 2018, pp. 6136–55, doi:<a href="https://doi.org/10.1029/2017jc013591">10.1029/2017jc013591</a>.'
  short: 'O. Richet, J.-M. Chomaz, C.J. Muller, Journal of Geophysical Research: Oceans
    123 (2018) 6136–6155.'
date_created: 2021-02-15T14:17:25Z
date_published: 2018-09-01T00:00:00Z
date_updated: 2022-01-24T12:39:03Z
day: '01'
doi: 10.1029/2017jc013591
extern: '1'
intvolume: '       123'
issue: '9'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.1029/2017JC013591
month: '09'
oa: 1
oa_version: Published Version
page: 6136-6155
publication: 'Journal of Geophysical Research: Oceans'
publication_identifier:
  issn:
  - 2169-9275
publication_status: published
publisher: American Geophysical Union
quality_controlled: '1'
status: public
title: 'Internal tide dissipation at topography: Triadic resonant instability equatorward
  and evanescent waves poleward of the critical latitude'
type: journal_article
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 123
year: '2018'
...
---
_id: '9141'
abstract:
- lang: eng
  text: The breaking of internal tides is believed to provide a large part of the
    power needed to mix the abyssal ocean and sustain the meridional overturning circulation.
    Both the fraction of internal tide energy that is dissipated locally and the resulting
    vertical mixing distribution are crucial for the ocean state, but remain poorly
    quantified. Here we present a first worldwide estimate of mixing due to internal
    tides generated at small‐scale abyssal hills. Our estimate is based on linear
    wave theory, a nonlinear parameterization for wave breaking and uses quasi‐global
    small‐scale abyssal hill bathymetry, stratification, and tidal data. We show that
    a large fraction of abyssal‐hill generated internal tide energy is locally dissipated
    over mid‐ocean ridges in the Southern Hemisphere. Significant dissipation occurs
    above ridge crests, and, upon rescaling by the local stratification, follows a
    monotonic exponential decay with height off the bottom, with a nonuniform decay
    scale. We however show that a substantial part of the dissipation occurs over
    the smoother flanks of mid‐ocean ridges, and exhibits a middepth maximum due to
    the interplay of wave amplitude with stratification. We link the three‐dimensional
    map of dissipation to abyssal hills characteristics, ocean stratification, and
    tidal forcing, and discuss its potential implementation in time‐evolving parameterizations
    for global climate models. Current tidal parameterizations only account for waves
    generated at large‐scale satellite‐resolved bathymetry. Our results suggest that
    the presence of small‐scale, mostly unresolved abyssal hills could significantly
    enhance the spatial inhomogeneity of tidal mixing, particularly above mid‐ocean
    ridges in the Southern Hemisphere.
article_processing_charge: No
article_type: original
author:
- first_name: Adrien
  full_name: Lefauve, Adrien
  last_name: Lefauve
- first_name: Caroline J
  full_name: Muller, Caroline J
  id: f978ccb0-3f7f-11eb-b193-b0e2bd13182b
  last_name: Muller
  orcid: 0000-0001-5836-5350
- first_name: Angélique
  full_name: Melet, Angélique
  last_name: Melet
citation:
  ama: 'Lefauve A, Muller CJ, Melet A. A three-dimensional map of tidal dissipation
    over abyssal hills. <i>Journal of Geophysical Research: Oceans</i>. 2015;120(7):4760-4777.
    doi:<a href="https://doi.org/10.1002/2014jc010598">10.1002/2014jc010598</a>'
  apa: 'Lefauve, A., Muller, C. J., &#38; Melet, A. (2015). A three-dimensional map
    of tidal dissipation over abyssal hills. <i>Journal of Geophysical Research: Oceans</i>.
    American Geophysical Union. <a href="https://doi.org/10.1002/2014jc010598">https://doi.org/10.1002/2014jc010598</a>'
  chicago: 'Lefauve, Adrien, Caroline J Muller, and Angélique Melet. “A Three-Dimensional
    Map of Tidal Dissipation over Abyssal Hills.” <i>Journal of Geophysical Research:
    Oceans</i>. American Geophysical Union, 2015. <a href="https://doi.org/10.1002/2014jc010598">https://doi.org/10.1002/2014jc010598</a>.'
  ieee: 'A. Lefauve, C. J. Muller, and A. Melet, “A three-dimensional map of tidal
    dissipation over abyssal hills,” <i>Journal of Geophysical Research: Oceans</i>,
    vol. 120, no. 7. American Geophysical Union, pp. 4760–4777, 2015.'
  ista: 'Lefauve A, Muller CJ, Melet A. 2015. A three-dimensional map of tidal dissipation
    over abyssal hills. Journal of Geophysical Research: Oceans. 120(7), 4760–4777.'
  mla: 'Lefauve, Adrien, et al. “A Three-Dimensional Map of Tidal Dissipation over
    Abyssal Hills.” <i>Journal of Geophysical Research: Oceans</i>, vol. 120, no.
    7, American Geophysical Union, 2015, pp. 4760–77, doi:<a href="https://doi.org/10.1002/2014jc010598">10.1002/2014jc010598</a>.'
  short: 'A. Lefauve, C.J. Muller, A. Melet, Journal of Geophysical Research: Oceans
    120 (2015) 4760–4777.'
date_created: 2021-02-15T14:21:49Z
date_published: 2015-06-08T00:00:00Z
date_updated: 2022-01-24T13:45:41Z
day: '08'
doi: 10.1002/2014jc010598
extern: '1'
intvolume: '       120'
issue: '7'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.1002/2014JC010598
month: '06'
oa: 1
oa_version: Published Version
page: 4760-4777
publication: 'Journal of Geophysical Research: Oceans'
publication_identifier:
  issn:
  - 2169-9275
publication_status: published
publisher: American Geophysical Union
quality_controlled: '1'
status: public
title: A three-dimensional map of tidal dissipation over abyssal hills
type: journal_article
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 120
year: '2015'
...
---
_id: '9153'
abstract:
- lang: eng
  text: 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° 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.
article_processing_charge: No
article_type: original
author:
- first_name: Angélique
  full_name: Melet, Angélique
  last_name: Melet
- first_name: Maxim
  full_name: Nikurashin, Maxim
  last_name: Nikurashin
- first_name: Caroline J
  full_name: Muller, Caroline J
  id: f978ccb0-3f7f-11eb-b193-b0e2bd13182b
  last_name: Muller
  orcid: 0000-0001-5836-5350
- first_name: S.
  full_name: Falahat, S.
  last_name: Falahat
- first_name: Jonas
  full_name: Nycander, Jonas
  last_name: Nycander
- first_name: Patrick G.
  full_name: Timko, Patrick G.
  last_name: Timko
- first_name: Brian K.
  full_name: Arbic, Brian K.
  last_name: Arbic
- first_name: John A.
  full_name: Goff, John A.
  last_name: Goff
citation:
  ama: 'Melet A, Nikurashin M, Muller CJ, et al. Internal tide generation by abyssal
    hills using analytical theory. <i>Journal of Geophysical Research: Oceans</i>.
    2013;118(11):6303-6318. doi:<a href="https://doi.org/10.1002/2013jc009212">10.1002/2013jc009212</a>'
  apa: 'Melet, A., Nikurashin, M., Muller, C. J., Falahat, S., Nycander, J., Timko,
    P. G., … Goff, J. A. (2013). Internal tide generation by abyssal hills using analytical
    theory. <i>Journal of Geophysical Research: Oceans</i>. American Geophysical Union.
    <a href="https://doi.org/10.1002/2013jc009212">https://doi.org/10.1002/2013jc009212</a>'
  chicago: 'Melet, Angélique, Maxim Nikurashin, Caroline J Muller, S. Falahat, Jonas
    Nycander, Patrick G. Timko, Brian K. Arbic, and John A. Goff. “Internal Tide Generation
    by Abyssal Hills Using Analytical Theory.” <i>Journal of Geophysical Research:
    Oceans</i>. American Geophysical Union, 2013. <a href="https://doi.org/10.1002/2013jc009212">https://doi.org/10.1002/2013jc009212</a>.'
  ieee: 'A. Melet <i>et al.</i>, “Internal tide generation by abyssal hills using
    analytical theory,” <i>Journal of Geophysical Research: Oceans</i>, vol. 118,
    no. 11. American Geophysical Union, pp. 6303–6318, 2013.'
  ista: 'Melet A, Nikurashin M, Muller CJ, Falahat S, Nycander J, Timko PG, Arbic
    BK, Goff JA. 2013. Internal tide generation by abyssal hills using analytical
    theory. Journal of Geophysical Research: Oceans. 118(11), 6303–6318.'
  mla: 'Melet, Angélique, et al. “Internal Tide Generation by Abyssal Hills Using
    Analytical Theory.” <i>Journal of Geophysical Research: Oceans</i>, vol. 118,
    no. 11, American Geophysical Union, 2013, pp. 6303–18, doi:<a href="https://doi.org/10.1002/2013jc009212">10.1002/2013jc009212</a>.'
  short: 'A. Melet, M. Nikurashin, C.J. Muller, S. Falahat, J. Nycander, P.G. Timko,
    B.K. Arbic, J.A. Goff, Journal of Geophysical Research: Oceans 118 (2013) 6303–6318.'
date_created: 2021-02-15T15:11:39Z
date_published: 2013-11-07T00:00:00Z
date_updated: 2022-01-24T13:46:15Z
day: '07'
doi: 10.1002/2013jc009212
extern: '1'
intvolume: '       118'
issue: '11'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.1002/2013JC009212
month: '11'
oa: 1
oa_version: Published Version
page: 6303-6318
publication: 'Journal of Geophysical Research: Oceans'
publication_identifier:
  issn:
  - 2169-9275
publication_status: published
publisher: American Geophysical Union
quality_controlled: '1'
status: public
title: Internal tide generation by abyssal hills using analytical theory
type: journal_article
user_id: 8b945eb4-e2f2-11eb-945a-df72226e66a9
volume: 118
year: '2013'
...