Sensitivity of a global coupled ocean-sea ice model to the parameterization of vertical mixing
Three numerical experiments have been carried out with a global coupled ice-ocean model to investigate its sensitivity to the treatment of vertical mixing in the upper ocean. In the first experiment, a widely used fixed profile of vertical diffusivity and viscosity is imposed, with large values in t...
Published in: | Journal of Geophysical Research: Oceans |
---|---|
Main Authors: | , , , |
Other Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Amer Geophysical Union
1999
|
Subjects: | |
Online Access: | http://hdl.handle.net/2078.1/44387 https://doi.org/10.1029/1999JC900099 |
id |
ftunivlouvain:oai:dial.uclouvain.be:boreal:44387 |
---|---|
record_format |
openpolar |
spelling |
ftunivlouvain:oai:dial.uclouvain.be:boreal:44387 2024-05-19T07:32:15+00:00 Sensitivity of a global coupled ocean-sea ice model to the parameterization of vertical mixing Goosse, Hugues Deleersnijder, Eric Fichefet, Thierry England, MH UCL - SC/PHYS - Département de physique UCL - SST/ELI/ELIC - Earth & Climate 1999 http://hdl.handle.net/2078.1/44387 https://doi.org/10.1029/1999JC900099 eng eng Amer Geophysical Union boreal:44387 http://hdl.handle.net/2078.1/44387 doi:10.1029/1999JC900099 urn:ISSN:0148-0227 Journal of Geophysical Research, Vol. 104, no. C6, p. 13681-13695 (1999) info:eu-repo/semantics/article 1999 ftunivlouvain https://doi.org/10.1029/1999JC900099 2024-04-24T01:48:21Z Three numerical experiments have been carried out with a global coupled ice-ocean model to investigate its sensitivity to the treatment of vertical mixing in the upper ocean. In the first experiment, a widely used fixed profile of vertical diffusivity and viscosity is imposed, with large values in the upper 50 m to crudely represent wind-driven mixing. In the second experiment, the eddy coefficients are functions of the Richardson number, and, in the third case, a relatively sophisticated parameterization, based on the turbulence closure scheme of Mellor and Yamada version 2.5, is introduced. We monitor the way the different mixing schemes affect the simulated ocean ventilation, water mass properties, and sea ice distributions. CFC uptake is also diagnosed in the model experiments. The simulation of the mixed layer depth is improved in the experiment which includes the sophisticated turbulence closure scheme. This results in a good representation of the upper ocean thermohaline structure and in heat exchange with the atmosphere within the range of current estimates. However, the en or in heat flux in the experiment with simple fixed vertical mixing coefficients can be as high as 50 W m(-2) in zonal mean during summer. Using CFC tracers allows us to demonstrate that the ventilation of the deep ocean is not significantly influenced by the paramertization of vertical mixing in the upper ocean. The only exception is the Southern Ocean. There, the ventilation is tao strong in all three experiments. However, modifications of the vertical diffusivity and, surprisingly, the vertical viscosity significantly affect the stability of the water column in this region through their influence on upper ocean salinity, resulting in a more realistic Southern Ocean circulation. The turbulence scheme also results in an improved simulation of Antarctic sea ice coverage . This is due to to a better simulation of the mixed layer depth and thus of heat exchanges between ice and ocean. The large-scale mean summer ice-ocean heat flux can ... Article in Journal/Newspaper Antarc* Antarctic Sea ice Southern Ocean DIAL@UCLouvain (Université catholique de Louvain) Journal of Geophysical Research: Oceans 104 C6 13681 13695 |
institution |
Open Polar |
collection |
DIAL@UCLouvain (Université catholique de Louvain) |
op_collection_id |
ftunivlouvain |
language |
English |
description |
Three numerical experiments have been carried out with a global coupled ice-ocean model to investigate its sensitivity to the treatment of vertical mixing in the upper ocean. In the first experiment, a widely used fixed profile of vertical diffusivity and viscosity is imposed, with large values in the upper 50 m to crudely represent wind-driven mixing. In the second experiment, the eddy coefficients are functions of the Richardson number, and, in the third case, a relatively sophisticated parameterization, based on the turbulence closure scheme of Mellor and Yamada version 2.5, is introduced. We monitor the way the different mixing schemes affect the simulated ocean ventilation, water mass properties, and sea ice distributions. CFC uptake is also diagnosed in the model experiments. The simulation of the mixed layer depth is improved in the experiment which includes the sophisticated turbulence closure scheme. This results in a good representation of the upper ocean thermohaline structure and in heat exchange with the atmosphere within the range of current estimates. However, the en or in heat flux in the experiment with simple fixed vertical mixing coefficients can be as high as 50 W m(-2) in zonal mean during summer. Using CFC tracers allows us to demonstrate that the ventilation of the deep ocean is not significantly influenced by the paramertization of vertical mixing in the upper ocean. The only exception is the Southern Ocean. There, the ventilation is tao strong in all three experiments. However, modifications of the vertical diffusivity and, surprisingly, the vertical viscosity significantly affect the stability of the water column in this region through their influence on upper ocean salinity, resulting in a more realistic Southern Ocean circulation. The turbulence scheme also results in an improved simulation of Antarctic sea ice coverage . This is due to to a better simulation of the mixed layer depth and thus of heat exchanges between ice and ocean. The large-scale mean summer ice-ocean heat flux can ... |
author2 |
UCL - SC/PHYS - Département de physique UCL - SST/ELI/ELIC - Earth & Climate |
format |
Article in Journal/Newspaper |
author |
Goosse, Hugues Deleersnijder, Eric Fichefet, Thierry England, MH |
spellingShingle |
Goosse, Hugues Deleersnijder, Eric Fichefet, Thierry England, MH Sensitivity of a global coupled ocean-sea ice model to the parameterization of vertical mixing |
author_facet |
Goosse, Hugues Deleersnijder, Eric Fichefet, Thierry England, MH |
author_sort |
Goosse, Hugues |
title |
Sensitivity of a global coupled ocean-sea ice model to the parameterization of vertical mixing |
title_short |
Sensitivity of a global coupled ocean-sea ice model to the parameterization of vertical mixing |
title_full |
Sensitivity of a global coupled ocean-sea ice model to the parameterization of vertical mixing |
title_fullStr |
Sensitivity of a global coupled ocean-sea ice model to the parameterization of vertical mixing |
title_full_unstemmed |
Sensitivity of a global coupled ocean-sea ice model to the parameterization of vertical mixing |
title_sort |
sensitivity of a global coupled ocean-sea ice model to the parameterization of vertical mixing |
publisher |
Amer Geophysical Union |
publishDate |
1999 |
url |
http://hdl.handle.net/2078.1/44387 https://doi.org/10.1029/1999JC900099 |
genre |
Antarc* Antarctic Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Sea ice Southern Ocean |
op_source |
Journal of Geophysical Research, Vol. 104, no. C6, p. 13681-13695 (1999) |
op_relation |
boreal:44387 http://hdl.handle.net/2078.1/44387 doi:10.1029/1999JC900099 urn:ISSN:0148-0227 |
op_doi |
https://doi.org/10.1029/1999JC900099 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
104 |
container_issue |
C6 |
container_start_page |
13681 |
op_container_end_page |
13695 |
_version_ |
1799470244391026688 |