Mediterranean outflow transports and entrainment estimates from observations and high-resolution modelling
International audience We use cross-slope sections of direct current observations together with a high resolution numerical simulation to revisit estimates of transports and entrainment in the Gulf of Cadiz. We provide a three dimensional picture of the outflow from the Mediterranean into the interm...
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ftunivbrest:oai:HAL:hal-01126645v1 2023-12-17T10:47:07+01:00 Mediterranean outflow transports and entrainment estimates from observations and high-resolution modelling Barbosa Aguiar, A.C. Peliz, A. Neves, F. Bashmachnikov, I. Carton, X. Instituto Dom Luiz Universidade de Lisboa = University of Lisbon (ULISBOA) Centro de Oceanografia Université de Lisbonne Departamento de Engenharia Geografica (DEGGE) Laboratoire de physique des océans (LPO) Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS) 2015-02 https://hal.science/hal-01126645 https://doi.org/10.1016/j.pocean.2014.11.008 en eng HAL CCSD Elsevier info:eu-repo/semantics/altIdentifier/doi/10.1016/j.pocean.2014.11.008 hal-01126645 https://hal.science/hal-01126645 doi:10.1016/j.pocean.2014.11.008 ISSN: 0079-6611 Progress in Oceanography https://hal.science/hal-01126645 Progress in Oceanography, 2015, 131, pp.33-45. ⟨10.1016/j.pocean.2014.11.008⟩ MU velocity veins and thermohaline anomaly cores are not co-located Westward volume transport is 2.6–3.6 Sv in observations and 3.5 Sv in model Westward salinity and heat transports are of ∼1.3 psu Sv and ∼20 × 1012 W Entrainment of 1.1 Sv NACW from Lagrangian analysis in closed domain in GoC Most of NACW entrained comes from south and southwest borders [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2015 ftunivbrest https://doi.org/10.1016/j.pocean.2014.11.008 2023-11-21T23:43:42Z International audience We use cross-slope sections of direct current observations together with a high resolution numerical simulation to revisit estimates of transports and entrainment in the Gulf of Cadiz. We provide a three dimensional picture of the outflow from the Mediterranean into the intermediate layers of the Atlantic.In the model, the time-averaged Mediterranean Undercurrent is characterised by two cores of zonal velocity at 8°30′8°30′W: one at 500 m (in the σ1σ1 interval 31.6–31.8 kg m−3) and another around 1100 m (∼32.2 kg m−3) with maximum westward velocity of 0.36 m s−1. A single well defined vein of saltier and warmer water (salinity maximum ∼36.9 psu, 1 psu = 1 kg salt/1000 kg seawater) is found attached to the slope, centred at 1300 m (32.2–32.4 kg m−3). The observational sections corroborate this description but instant maximum velocity reaches 0.6 m s−1 whereas salinity peaks just above 36.5 psu. Unlike what was previously thought, the velocity veins and the thermohaline anomaly cores are not co-located.At the Strait of Gibraltar, we estimate that the transport of pure Mediterranean Water (S > 38.4 psu) is about 0.48 Sv (1 Sv = 106 m3 s−1). Near the Portimão Canyon, the results for westward transport (31.6–32.6 kg m−3) computed from observations are within the range 2.6–3.6 Sv and the time-mean estimate from the numerical simulation is of 3.5 Sv. The westward salinity and heat transports are of ≲1.3 psu Sv (1 psu Sv = 103 m3 s−1) andView the MathML source∼20×1012W, from observational and numerical data alike.By tracking water masses within a closed domain in the Gulf of Cadiz, we find that most of the North Atlantic Water entrained into the undercurrent is supplied through the south and southwest borders. After analysing volume balances per layer, we conclude that the entrainment from shallower layers is around 1.1 Sv in total: 0.32, 0.34, 0.40 and 0.04 Sv distributed by four equally spaced density intervals (0.2 kg m−3) between isopycnals 31.8 and 32.6 kg m−3. Article in Journal/Newspaper North Atlantic Université de Bretagne Occidentale: HAL Progress in Oceanography 131 33 45 |
institution |
Open Polar |
collection |
Université de Bretagne Occidentale: HAL |
op_collection_id |
ftunivbrest |
language |
English |
topic |
MU velocity veins and thermohaline anomaly cores are not co-located Westward volume transport is 2.6–3.6 Sv in observations and 3.5 Sv in model Westward salinity and heat transports are of ∼1.3 psu Sv and ∼20 × 1012 W Entrainment of 1.1 Sv NACW from Lagrangian analysis in closed domain in GoC Most of NACW entrained comes from south and southwest borders [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography [SDU]Sciences of the Universe [physics] |
spellingShingle |
MU velocity veins and thermohaline anomaly cores are not co-located Westward volume transport is 2.6–3.6 Sv in observations and 3.5 Sv in model Westward salinity and heat transports are of ∼1.3 psu Sv and ∼20 × 1012 W Entrainment of 1.1 Sv NACW from Lagrangian analysis in closed domain in GoC Most of NACW entrained comes from south and southwest borders [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography [SDU]Sciences of the Universe [physics] Barbosa Aguiar, A.C. Peliz, A. Neves, F. Bashmachnikov, I. Carton, X. Mediterranean outflow transports and entrainment estimates from observations and high-resolution modelling |
topic_facet |
MU velocity veins and thermohaline anomaly cores are not co-located Westward volume transport is 2.6–3.6 Sv in observations and 3.5 Sv in model Westward salinity and heat transports are of ∼1.3 psu Sv and ∼20 × 1012 W Entrainment of 1.1 Sv NACW from Lagrangian analysis in closed domain in GoC Most of NACW entrained comes from south and southwest borders [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography [SDU]Sciences of the Universe [physics] |
description |
International audience We use cross-slope sections of direct current observations together with a high resolution numerical simulation to revisit estimates of transports and entrainment in the Gulf of Cadiz. We provide a three dimensional picture of the outflow from the Mediterranean into the intermediate layers of the Atlantic.In the model, the time-averaged Mediterranean Undercurrent is characterised by two cores of zonal velocity at 8°30′8°30′W: one at 500 m (in the σ1σ1 interval 31.6–31.8 kg m−3) and another around 1100 m (∼32.2 kg m−3) with maximum westward velocity of 0.36 m s−1. A single well defined vein of saltier and warmer water (salinity maximum ∼36.9 psu, 1 psu = 1 kg salt/1000 kg seawater) is found attached to the slope, centred at 1300 m (32.2–32.4 kg m−3). The observational sections corroborate this description but instant maximum velocity reaches 0.6 m s−1 whereas salinity peaks just above 36.5 psu. Unlike what was previously thought, the velocity veins and the thermohaline anomaly cores are not co-located.At the Strait of Gibraltar, we estimate that the transport of pure Mediterranean Water (S > 38.4 psu) is about 0.48 Sv (1 Sv = 106 m3 s−1). Near the Portimão Canyon, the results for westward transport (31.6–32.6 kg m−3) computed from observations are within the range 2.6–3.6 Sv and the time-mean estimate from the numerical simulation is of 3.5 Sv. The westward salinity and heat transports are of ≲1.3 psu Sv (1 psu Sv = 103 m3 s−1) andView the MathML source∼20×1012W, from observational and numerical data alike.By tracking water masses within a closed domain in the Gulf of Cadiz, we find that most of the North Atlantic Water entrained into the undercurrent is supplied through the south and southwest borders. After analysing volume balances per layer, we conclude that the entrainment from shallower layers is around 1.1 Sv in total: 0.32, 0.34, 0.40 and 0.04 Sv distributed by four equally spaced density intervals (0.2 kg m−3) between isopycnals 31.8 and 32.6 kg m−3. |
author2 |
Instituto Dom Luiz Universidade de Lisboa = University of Lisbon (ULISBOA) Centro de Oceanografia Université de Lisbonne Departamento de Engenharia Geografica (DEGGE) Laboratoire de physique des océans (LPO) Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Barbosa Aguiar, A.C. Peliz, A. Neves, F. Bashmachnikov, I. Carton, X. |
author_facet |
Barbosa Aguiar, A.C. Peliz, A. Neves, F. Bashmachnikov, I. Carton, X. |
author_sort |
Barbosa Aguiar, A.C. |
title |
Mediterranean outflow transports and entrainment estimates from observations and high-resolution modelling |
title_short |
Mediterranean outflow transports and entrainment estimates from observations and high-resolution modelling |
title_full |
Mediterranean outflow transports and entrainment estimates from observations and high-resolution modelling |
title_fullStr |
Mediterranean outflow transports and entrainment estimates from observations and high-resolution modelling |
title_full_unstemmed |
Mediterranean outflow transports and entrainment estimates from observations and high-resolution modelling |
title_sort |
mediterranean outflow transports and entrainment estimates from observations and high-resolution modelling |
publisher |
HAL CCSD |
publishDate |
2015 |
url |
https://hal.science/hal-01126645 https://doi.org/10.1016/j.pocean.2014.11.008 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
ISSN: 0079-6611 Progress in Oceanography https://hal.science/hal-01126645 Progress in Oceanography, 2015, 131, pp.33-45. ⟨10.1016/j.pocean.2014.11.008⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.pocean.2014.11.008 hal-01126645 https://hal.science/hal-01126645 doi:10.1016/j.pocean.2014.11.008 |
op_doi |
https://doi.org/10.1016/j.pocean.2014.11.008 |
container_title |
Progress in Oceanography |
container_volume |
131 |
container_start_page |
33 |
op_container_end_page |
45 |
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1785570871851614208 |