The Lifecycle of Semidiurnal Internal Tides over the Northern Mid-Atlantic Ridge
The life cycle of semidiurnal internal tides over the Mid-Atlantic Ridge (MAR) sector south of the Azores is investigated using in situ, a high-resolution mooring and microstructure profiler, and satellite data, in combination with a theoretical model of barotropic-to-baroclinic tidal energy convers...
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ftarchimer:oai:archimer.ifremer.fr:87473 2023-05-15T17:35:21+02:00 The Lifecycle of Semidiurnal Internal Tides over the Northern Mid-Atlantic Ridge Vic, Clement Garabato, Alberto C. Naveira Green, J. A. Mattias Spingys, Carl Forryan, Alexander Zhao, Zhongxiang Sharples, Jonathan 2018-01 application/pdf https://archimer.ifremer.fr/doc/00763/87473/92966.pdf https://doi.org/10.1175/JPO-D-17-0121.1 https://archimer.ifremer.fr/doc/00763/87473/ eng eng Amer Meteorological Soc https://archimer.ifremer.fr/doc/00763/87473/92966.pdf doi:10.1175/JPO-D-17-0121.1 https://archimer.ifremer.fr/doc/00763/87473/ info:eu-repo/semantics/openAccess restricted use Journal Of Physical Oceanography (0022-3670) (Amer Meteorological Soc), 2018-01 , Vol. 48 , N. 1 , P. 61-80 North Atlantic Ocean Diapycnal mixing Internal waves Mixing In situ oceanic observations Satellite observations text Publication info:eu-repo/semantics/article 2018 ftarchimer https://doi.org/10.1175/JPO-D-17-0121.1 2022-04-05T22:50:03Z The life cycle of semidiurnal internal tides over the Mid-Atlantic Ridge (MAR) sector south of the Azores is investigated using in situ, a high-resolution mooring and microstructure profiler, and satellite data, in combination with a theoretical model of barotropic-to-baroclinic tidal energy conversion. The mooring analysis reveals that the internal tide horizontal energy flux is dominated by mode 1 and that energy density is more distributed among modes 1-10. Most modes are compatible with an interpretation in terms of standing internal tides, suggesting that they result from interactions between waves generated over the MAR. Internal tide energy is thus concentrated above the ridge and is eventually available for local diapycnal mixing, as endorsed by the elevated rates of turbulent energy dissipation epsilon estimated from microstructure measurements. A spring-neap modulation of energy density on the MAR is found to originate from the remote generation and radiation of strong mode-1 internal tides from the Atlantis-Meteor Seamount Complex. Similar fortnightly variability of a factor of 2 is observed in epsilon, but this signal's origin cannot be determined unambiguously. A regional tidal energy budget highlights the significance of high-mode generation, with 81% of the energy lost by the barotropic tide being converted into modes >1 and only 9% into mode 1. This has important implications for the fraction (q) of local dissipation to the total energy conversion, which is regionally estimated to be similar to 0.5. This result is in stark contrast with the Hawaiian Ridge system, where the radiation of mode-1 internal tides accounts for 30% of the regional energy conversion, and q<0.25. Article in Journal/Newspaper North Atlantic Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) Meteor Seamount ENVELOPE(8.500,8.500,-48.000,-48.000) Mid-Atlantic Ridge Journal of Physical Oceanography 48 1 61 80 |
institution |
Open Polar |
collection |
Archimer (Archive Institutionnelle de l'Ifremer - Institut français de recherche pour l'exploitation de la mer) |
op_collection_id |
ftarchimer |
language |
English |
topic |
North Atlantic Ocean Diapycnal mixing Internal waves Mixing In situ oceanic observations Satellite observations |
spellingShingle |
North Atlantic Ocean Diapycnal mixing Internal waves Mixing In situ oceanic observations Satellite observations Vic, Clement Garabato, Alberto C. Naveira Green, J. A. Mattias Spingys, Carl Forryan, Alexander Zhao, Zhongxiang Sharples, Jonathan The Lifecycle of Semidiurnal Internal Tides over the Northern Mid-Atlantic Ridge |
topic_facet |
North Atlantic Ocean Diapycnal mixing Internal waves Mixing In situ oceanic observations Satellite observations |
description |
The life cycle of semidiurnal internal tides over the Mid-Atlantic Ridge (MAR) sector south of the Azores is investigated using in situ, a high-resolution mooring and microstructure profiler, and satellite data, in combination with a theoretical model of barotropic-to-baroclinic tidal energy conversion. The mooring analysis reveals that the internal tide horizontal energy flux is dominated by mode 1 and that energy density is more distributed among modes 1-10. Most modes are compatible with an interpretation in terms of standing internal tides, suggesting that they result from interactions between waves generated over the MAR. Internal tide energy is thus concentrated above the ridge and is eventually available for local diapycnal mixing, as endorsed by the elevated rates of turbulent energy dissipation epsilon estimated from microstructure measurements. A spring-neap modulation of energy density on the MAR is found to originate from the remote generation and radiation of strong mode-1 internal tides from the Atlantis-Meteor Seamount Complex. Similar fortnightly variability of a factor of 2 is observed in epsilon, but this signal's origin cannot be determined unambiguously. A regional tidal energy budget highlights the significance of high-mode generation, with 81% of the energy lost by the barotropic tide being converted into modes >1 and only 9% into mode 1. This has important implications for the fraction (q) of local dissipation to the total energy conversion, which is regionally estimated to be similar to 0.5. This result is in stark contrast with the Hawaiian Ridge system, where the radiation of mode-1 internal tides accounts for 30% of the regional energy conversion, and q<0.25. |
format |
Article in Journal/Newspaper |
author |
Vic, Clement Garabato, Alberto C. Naveira Green, J. A. Mattias Spingys, Carl Forryan, Alexander Zhao, Zhongxiang Sharples, Jonathan |
author_facet |
Vic, Clement Garabato, Alberto C. Naveira Green, J. A. Mattias Spingys, Carl Forryan, Alexander Zhao, Zhongxiang Sharples, Jonathan |
author_sort |
Vic, Clement |
title |
The Lifecycle of Semidiurnal Internal Tides over the Northern Mid-Atlantic Ridge |
title_short |
The Lifecycle of Semidiurnal Internal Tides over the Northern Mid-Atlantic Ridge |
title_full |
The Lifecycle of Semidiurnal Internal Tides over the Northern Mid-Atlantic Ridge |
title_fullStr |
The Lifecycle of Semidiurnal Internal Tides over the Northern Mid-Atlantic Ridge |
title_full_unstemmed |
The Lifecycle of Semidiurnal Internal Tides over the Northern Mid-Atlantic Ridge |
title_sort |
lifecycle of semidiurnal internal tides over the northern mid-atlantic ridge |
publisher |
Amer Meteorological Soc |
publishDate |
2018 |
url |
https://archimer.ifremer.fr/doc/00763/87473/92966.pdf https://doi.org/10.1175/JPO-D-17-0121.1 https://archimer.ifremer.fr/doc/00763/87473/ |
long_lat |
ENVELOPE(8.500,8.500,-48.000,-48.000) |
geographic |
Meteor Seamount Mid-Atlantic Ridge |
geographic_facet |
Meteor Seamount Mid-Atlantic Ridge |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Journal Of Physical Oceanography (0022-3670) (Amer Meteorological Soc), 2018-01 , Vol. 48 , N. 1 , P. 61-80 |
op_relation |
https://archimer.ifremer.fr/doc/00763/87473/92966.pdf doi:10.1175/JPO-D-17-0121.1 https://archimer.ifremer.fr/doc/00763/87473/ |
op_rights |
info:eu-repo/semantics/openAccess restricted use |
op_doi |
https://doi.org/10.1175/JPO-D-17-0121.1 |
container_title |
Journal of Physical Oceanography |
container_volume |
48 |
container_issue |
1 |
container_start_page |
61 |
op_container_end_page |
80 |
_version_ |
1766134478578647040 |