A laboratory analogue of current-topography interaction in the Southern Ocean
International audience The Antarctic Circumpolar Current (ACC) is an active site of turbulent mixing in the circulation of Southern Ocean (SO). This is attributed to the instabilities of waves and eddies resulting from the interaction of geostrophic flow with bottom topography.For the first time, th...
Main Authors: | , , , , , |
---|---|
Other Authors: | , , , |
Format: | Conference Object |
Language: | English |
Published: |
HAL CCSD
2017
|
Subjects: | |
Online Access: | https://hal.science/hal-01937982 |
id |
ftinsu:oai:HAL:hal-01937982v1 |
---|---|
record_format |
openpolar |
spelling |
ftinsu:oai:HAL:hal-01937982v1 2024-04-28T08:03:06+00:00 A laboratory analogue of current-topography interaction in the Southern Ocean Ajayi, Adekunle-Opeoluwa Sommeria, Joël Raja, Keshav Jayakrishnan Staquet, Chantal Viboud, Samuel Voisin, Bruno Institut des Géosciences de l’Environnement (IGE) Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ) Laboratoire des Écoulements Géophysiques et Industriels Grenoble (LEGI ) Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ) Vienna, Austria 2017-04-23 https://hal.science/hal-01937982 en eng HAL CCSD hal-01937982 https://hal.science/hal-01937982 EGU General Assembly 2017 https://hal.science/hal-01937982 EGU General Assembly 2017, Apr 2017, Vienna, Austria https://www.egu2017.eu [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph] info:eu-repo/semantics/conferenceObject Conference papers 2017 ftinsu 2024-04-05T00:44:36Z International audience The Antarctic Circumpolar Current (ACC) is an active site of turbulent mixing in the circulation of Southern Ocean (SO). This is attributed to the instabilities of waves and eddies resulting from the interaction of geostrophic flow with bottom topography.For the first time, the dynamics of the Antarctic Circumpolar Current is reproduced in the laboratory using the rotating Coriolis platform with diameter 13m. The tank is filled with a 1m thick layer of uniformly stratified salt water. A uniform circular current around the tank is produced by a small change of tank rotation speed which persists by inertia for the duration of the experiment, during which the flow conditions can be considered quasi-steady. Spherical cap(s) was introduce as bottom topography in the flow configuration. The experimental module was divided into two cases: with Coriolis effect and without Coriolis effect. Several experiments with multiple caps to mimic rough topography features were conducted with various values of Froude and Rossby number.Waves and eddies resulting from the interaction of the flow with the topography were studied. It was re- alised that rotation greatly enhances vertical transport of momentum from the bottom. Inertial oscillations were observed and likely contribute to this transport. Turbulence generation was observed close the topography but also in the fluid interior far above it, which presumably results from wave breaking. Consistently, analysis of the density probes showed vertical mixing in the water column both at the bottom and in the interior. The link with the theoretical modelling by Nikurashin & Ferrari (2010) and Labreuche et al. (2016) will be discussed. Conference Object Antarc* Antarctic Southern Ocean Institut national des sciences de l'Univers: HAL-INSU |
institution |
Open Polar |
collection |
Institut national des sciences de l'Univers: HAL-INSU |
op_collection_id |
ftinsu |
language |
English |
topic |
[PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph] |
spellingShingle |
[PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph] Ajayi, Adekunle-Opeoluwa Sommeria, Joël Raja, Keshav Jayakrishnan Staquet, Chantal Viboud, Samuel Voisin, Bruno A laboratory analogue of current-topography interaction in the Southern Ocean |
topic_facet |
[PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph] |
description |
International audience The Antarctic Circumpolar Current (ACC) is an active site of turbulent mixing in the circulation of Southern Ocean (SO). This is attributed to the instabilities of waves and eddies resulting from the interaction of geostrophic flow with bottom topography.For the first time, the dynamics of the Antarctic Circumpolar Current is reproduced in the laboratory using the rotating Coriolis platform with diameter 13m. The tank is filled with a 1m thick layer of uniformly stratified salt water. A uniform circular current around the tank is produced by a small change of tank rotation speed which persists by inertia for the duration of the experiment, during which the flow conditions can be considered quasi-steady. Spherical cap(s) was introduce as bottom topography in the flow configuration. The experimental module was divided into two cases: with Coriolis effect and without Coriolis effect. Several experiments with multiple caps to mimic rough topography features were conducted with various values of Froude and Rossby number.Waves and eddies resulting from the interaction of the flow with the topography were studied. It was re- alised that rotation greatly enhances vertical transport of momentum from the bottom. Inertial oscillations were observed and likely contribute to this transport. Turbulence generation was observed close the topography but also in the fluid interior far above it, which presumably results from wave breaking. Consistently, analysis of the density probes showed vertical mixing in the water column both at the bottom and in the interior. The link with the theoretical modelling by Nikurashin & Ferrari (2010) and Labreuche et al. (2016) will be discussed. |
author2 |
Institut des Géosciences de l’Environnement (IGE) Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ) Laboratoire des Écoulements Géophysiques et Industriels Grenoble (LEGI ) Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ) |
format |
Conference Object |
author |
Ajayi, Adekunle-Opeoluwa Sommeria, Joël Raja, Keshav Jayakrishnan Staquet, Chantal Viboud, Samuel Voisin, Bruno |
author_facet |
Ajayi, Adekunle-Opeoluwa Sommeria, Joël Raja, Keshav Jayakrishnan Staquet, Chantal Viboud, Samuel Voisin, Bruno |
author_sort |
Ajayi, Adekunle-Opeoluwa |
title |
A laboratory analogue of current-topography interaction in the Southern Ocean |
title_short |
A laboratory analogue of current-topography interaction in the Southern Ocean |
title_full |
A laboratory analogue of current-topography interaction in the Southern Ocean |
title_fullStr |
A laboratory analogue of current-topography interaction in the Southern Ocean |
title_full_unstemmed |
A laboratory analogue of current-topography interaction in the Southern Ocean |
title_sort |
laboratory analogue of current-topography interaction in the southern ocean |
publisher |
HAL CCSD |
publishDate |
2017 |
url |
https://hal.science/hal-01937982 |
op_coverage |
Vienna, Austria |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_source |
EGU General Assembly 2017 https://hal.science/hal-01937982 EGU General Assembly 2017, Apr 2017, Vienna, Austria https://www.egu2017.eu |
op_relation |
hal-01937982 https://hal.science/hal-01937982 |
_version_ |
1797574272853475328 |