Sinking of dense north atlantic waters in a global ocean model: Location and controls
We investigate the characteristics of the sinking of dense waters in the North Atlantic Ocean that constitute the downwelling limb of the Atlantic Meridional Overturning Circulation (AMOC) as simulated by two global ocean models: an eddy-permitting model at 1/48 resolution and its coarser 18 counter...
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ftunivutrecht:oai:dspace.library.uu.nl:1874/377524 2023-11-12T04:21:46+01:00 Sinking of dense north atlantic waters in a global ocean model: Location and controls Katsman, C. A. Drijfhout, S. S. Dijkstra, H. A. Spall, M. A. Sub Dynamics Meteorology Sub Physical Oceanography Dep Natuurkunde Marine and Atmospheric Research 2018-01-01 image/pdf https://dspace.library.uu.nl/handle/1874/377524 en eng 2169-9275 https://dspace.library.uu.nl/handle/1874/377524 info:eu-repo/semantics/OpenAccess Geophysics Forestry Oceanography Aquatic Science Ecology Water Science and Technology Soil Science Geochemistry and Petrology Earth-Surface Processes Atmospheric Science Space and Planetary Science Earth and Planetary Sciences (miscellaneous) Palaeontology Article 2018 ftunivutrecht 2023-11-01T23:20:09Z We investigate the characteristics of the sinking of dense waters in the North Atlantic Ocean that constitute the downwelling limb of the Atlantic Meridional Overturning Circulation (AMOC) as simulated by two global ocean models: an eddy-permitting model at 1/48 resolution and its coarser 18 counterpart. In line with simple geostrophic considerations, it is shown that the sinking predominantly occurs in a narrow region close to the continental boundary in both model simulations. That is, the regions where convection is deepest do not coincide with regions where most dense waters sink. The amount of near-boundary sinking that occurs varies regionally. For the 1/48 resolution model, these variations are in quantitative agreement with a relation based on geostrophy and a thermodynamic balance between buoyancy loss and alongshore advection of density, which links the amount of sinking to changes in density along the edge of the North Atlantic Ocean. In the 18 model, the amount and location of sinking appears not to be governed by this simple relation, possibly due to the large impact of overflows and nonnegligible cross-shore density advection. If this poor representation of the processes governing the sinking of dense waters in the North Atlantic Ocean is a generic feature of such low-resolution models, the response of the AMOC to changes in climate simulated by this type of models needs to be evaluated with care. Article in Journal/Newspaper North Atlantic Utrecht University Repository |
institution |
Open Polar |
collection |
Utrecht University Repository |
op_collection_id |
ftunivutrecht |
language |
English |
topic |
Geophysics Forestry Oceanography Aquatic Science Ecology Water Science and Technology Soil Science Geochemistry and Petrology Earth-Surface Processes Atmospheric Science Space and Planetary Science Earth and Planetary Sciences (miscellaneous) Palaeontology |
spellingShingle |
Geophysics Forestry Oceanography Aquatic Science Ecology Water Science and Technology Soil Science Geochemistry and Petrology Earth-Surface Processes Atmospheric Science Space and Planetary Science Earth and Planetary Sciences (miscellaneous) Palaeontology Katsman, C. A. Drijfhout, S. S. Dijkstra, H. A. Spall, M. A. Sinking of dense north atlantic waters in a global ocean model: Location and controls |
topic_facet |
Geophysics Forestry Oceanography Aquatic Science Ecology Water Science and Technology Soil Science Geochemistry and Petrology Earth-Surface Processes Atmospheric Science Space and Planetary Science Earth and Planetary Sciences (miscellaneous) Palaeontology |
description |
We investigate the characteristics of the sinking of dense waters in the North Atlantic Ocean that constitute the downwelling limb of the Atlantic Meridional Overturning Circulation (AMOC) as simulated by two global ocean models: an eddy-permitting model at 1/48 resolution and its coarser 18 counterpart. In line with simple geostrophic considerations, it is shown that the sinking predominantly occurs in a narrow region close to the continental boundary in both model simulations. That is, the regions where convection is deepest do not coincide with regions where most dense waters sink. The amount of near-boundary sinking that occurs varies regionally. For the 1/48 resolution model, these variations are in quantitative agreement with a relation based on geostrophy and a thermodynamic balance between buoyancy loss and alongshore advection of density, which links the amount of sinking to changes in density along the edge of the North Atlantic Ocean. In the 18 model, the amount and location of sinking appears not to be governed by this simple relation, possibly due to the large impact of overflows and nonnegligible cross-shore density advection. If this poor representation of the processes governing the sinking of dense waters in the North Atlantic Ocean is a generic feature of such low-resolution models, the response of the AMOC to changes in climate simulated by this type of models needs to be evaluated with care. |
author2 |
Sub Dynamics Meteorology Sub Physical Oceanography Dep Natuurkunde Marine and Atmospheric Research |
format |
Article in Journal/Newspaper |
author |
Katsman, C. A. Drijfhout, S. S. Dijkstra, H. A. Spall, M. A. |
author_facet |
Katsman, C. A. Drijfhout, S. S. Dijkstra, H. A. Spall, M. A. |
author_sort |
Katsman, C. A. |
title |
Sinking of dense north atlantic waters in a global ocean model: Location and controls |
title_short |
Sinking of dense north atlantic waters in a global ocean model: Location and controls |
title_full |
Sinking of dense north atlantic waters in a global ocean model: Location and controls |
title_fullStr |
Sinking of dense north atlantic waters in a global ocean model: Location and controls |
title_full_unstemmed |
Sinking of dense north atlantic waters in a global ocean model: Location and controls |
title_sort |
sinking of dense north atlantic waters in a global ocean model: location and controls |
publishDate |
2018 |
url |
https://dspace.library.uu.nl/handle/1874/377524 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
2169-9275 https://dspace.library.uu.nl/handle/1874/377524 |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1782337044386676736 |