Effects of vertical variations of thickness diffusivity in an ocean general circulation model
The effects of a prescribed surface intensification of the thickness (and isopycnal) diffusivity on the solutions of an ocean general circulation model are documented. The model is the coarse resolution version of the ocean component of the National Center for Atmospheric Research (NCAR) Community C...
Published in: | Ocean Modelling |
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Format: | Article in Journal/Newspaper |
Language: | English |
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Elsevier Ltd.
2007
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Online Access: | http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-004-303 https://doi.org/10.1016/j.ocemod.2007.03.006 |
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ftncar:oai:drupal-site.org:articles_6961 2023-10-01T03:59:37+02:00 Effects of vertical variations of thickness diffusivity in an ocean general circulation model Danabasoglu, Gokhan (author) Marshall, John (author) 2007-02-01 http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-004-303 https://doi.org/10.1016/j.ocemod.2007.03.006 en eng Elsevier Ltd. Ocean Modelling http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-004-303 doi:10.1016/j.ocemod.2007.03.006 ark:/85065/d70002bf Copyright 2007 Elsevier. Ocean general circulation model Mesoscale eddy parameterization Vertically varying thickness diffusivity Text article 2007 ftncar https://doi.org/10.1016/j.ocemod.2007.03.006 2023-09-04T18:22:01Z The effects of a prescribed surface intensification of the thickness (and isopycnal) diffusivity on the solutions of an ocean general circulation model are documented. The model is the coarse resolution version of the ocean component of the National Center for Atmospheric Research (NCAR) Community Climate System Model version 3 (CCSM3). Guided by the results of Ferreira et al. (2005) [Ferreira, D., Marshall, J., Heimbach, P., 2005. Estimating eddy stresses by fitting dynamics to observations using a residual-mean ocean circulation model and its adjoint. J. Phys. Oceanogr. 35, 1891-1910.] we employ a vertical dependence of the diffusivity which varies with the stratification, N², and is thus large in the upper ocean and small in the abyss. We experiment with vertical variations of diffusivity which are as large as 4000 m² s⁻¹ within the surface diabatic layer, diminishing to 400 m² s⁻¹ or so by a depth of 2 km. The new solutions compare more favorably with the available observations than those of the control which uses a constant value of 800 m² s⁻¹ for both thickness and isopycnal diffusivities. These include an improved representation of the vertical structure and transport of the eddy-induced velocity in the upper-ocean North Pacific, a reduced warm bias in the upper ocean, including the equatorial Pacific, and improved southward heat transport in the low- to mid-latitude Southern Hemisphere. There is also a modest enhancement of abyssal stratification in the Southern Ocean. Article in Journal/Newspaper Southern Ocean OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Ferreira ENVELOPE(-62.050,-62.050,-64.600,-64.600) Pacific Southern Ocean Ocean Modelling 18 2 122 141 |
institution |
Open Polar |
collection |
OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
op_collection_id |
ftncar |
language |
English |
topic |
Ocean general circulation model Mesoscale eddy parameterization Vertically varying thickness diffusivity |
spellingShingle |
Ocean general circulation model Mesoscale eddy parameterization Vertically varying thickness diffusivity Effects of vertical variations of thickness diffusivity in an ocean general circulation model |
topic_facet |
Ocean general circulation model Mesoscale eddy parameterization Vertically varying thickness diffusivity |
description |
The effects of a prescribed surface intensification of the thickness (and isopycnal) diffusivity on the solutions of an ocean general circulation model are documented. The model is the coarse resolution version of the ocean component of the National Center for Atmospheric Research (NCAR) Community Climate System Model version 3 (CCSM3). Guided by the results of Ferreira et al. (2005) [Ferreira, D., Marshall, J., Heimbach, P., 2005. Estimating eddy stresses by fitting dynamics to observations using a residual-mean ocean circulation model and its adjoint. J. Phys. Oceanogr. 35, 1891-1910.] we employ a vertical dependence of the diffusivity which varies with the stratification, N², and is thus large in the upper ocean and small in the abyss. We experiment with vertical variations of diffusivity which are as large as 4000 m² s⁻¹ within the surface diabatic layer, diminishing to 400 m² s⁻¹ or so by a depth of 2 km. The new solutions compare more favorably with the available observations than those of the control which uses a constant value of 800 m² s⁻¹ for both thickness and isopycnal diffusivities. These include an improved representation of the vertical structure and transport of the eddy-induced velocity in the upper-ocean North Pacific, a reduced warm bias in the upper ocean, including the equatorial Pacific, and improved southward heat transport in the low- to mid-latitude Southern Hemisphere. There is also a modest enhancement of abyssal stratification in the Southern Ocean. |
author2 |
Danabasoglu, Gokhan (author) Marshall, John (author) |
format |
Article in Journal/Newspaper |
title |
Effects of vertical variations of thickness diffusivity in an ocean general circulation model |
title_short |
Effects of vertical variations of thickness diffusivity in an ocean general circulation model |
title_full |
Effects of vertical variations of thickness diffusivity in an ocean general circulation model |
title_fullStr |
Effects of vertical variations of thickness diffusivity in an ocean general circulation model |
title_full_unstemmed |
Effects of vertical variations of thickness diffusivity in an ocean general circulation model |
title_sort |
effects of vertical variations of thickness diffusivity in an ocean general circulation model |
publisher |
Elsevier Ltd. |
publishDate |
2007 |
url |
http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-004-303 https://doi.org/10.1016/j.ocemod.2007.03.006 |
long_lat |
ENVELOPE(-62.050,-62.050,-64.600,-64.600) |
geographic |
Ferreira Pacific Southern Ocean |
geographic_facet |
Ferreira Pacific Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
Ocean Modelling http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-004-303 doi:10.1016/j.ocemod.2007.03.006 ark:/85065/d70002bf |
op_rights |
Copyright 2007 Elsevier. |
op_doi |
https://doi.org/10.1016/j.ocemod.2007.03.006 |
container_title |
Ocean Modelling |
container_volume |
18 |
container_issue |
2 |
container_start_page |
122 |
op_container_end_page |
141 |
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1778533870169227264 |