Mozambique Channel Eddies in GCMs: A question of resolution and slippage
Mozambique Channel Eddies in GCMs: A question of resolution and slippage
Hydrographic observations in the 21st century have shown that the flow within the Mozambique
Channel is best described by a series of large poleward-propagating anticyclonic eddies, rather than, as
previously thought, a continuous intense western boundary current. The portrayal of this region in various runs of the NEMO 75-level model is found to vary between those two descriptions depending upon the resolution used and the implementation of the model's lateral boundary conditions. In a comparison of 1/4 ? resolution runs, the change of these conditions from free-slip to no-slip leads to the mean southward flow moving further offshore, with greater variability in the zonal and meridional velocities as the flow organises itself into eddies, and a reduction in total transport. If a realization of a model is unable to get these aspects of the physical flow correct, then this will significantly reduce its ability to show a realistic biological signal or long-term response to climate change. Further south, beyond Durban, the application of no-slip conditions similarly causes the mean Agulhas Current to lie further offshore, making it much more able to simulate Natal Pulses.
Indian Ocean: Mozambique Channel, NEMO, Spatial resolution, Boundary conditions, Stability, Natal Pulse (Current meandering)
56-67
Quartly, G.D.
3d1e4e87-f001-4d18-b95f-9bca4db6ff9d
de Cuevas, B.A.
01cc697c-2832-4de6-87bf-bf9f16c1f906
Coward, A.C.
53b78140-2e65-476a-b287-e8384a65224b
March 2013
Quartly, G.D.
3d1e4e87-f001-4d18-b95f-9bca4db6ff9d
de Cuevas, B.A.
01cc697c-2832-4de6-87bf-bf9f16c1f906
Coward, A.C.
53b78140-2e65-476a-b287-e8384a65224b
Quartly, G.D., de Cuevas, B.A. and Coward, A.C.
(2013)
Mozambique Channel Eddies in GCMs: A question of resolution and slippage.
Ocean Modelling, 63, .
(doi:10.1016/j.ocemod.2012.12.011).
Abstract
Hydrographic observations in the 21st century have shown that the flow within the Mozambique
Channel is best described by a series of large poleward-propagating anticyclonic eddies, rather than, as
previously thought, a continuous intense western boundary current. The portrayal of this region in various runs of the NEMO 75-level model is found to vary between those two descriptions depending upon the resolution used and the implementation of the model's lateral boundary conditions. In a comparison of 1/4 ? resolution runs, the change of these conditions from free-slip to no-slip leads to the mean southward flow moving further offshore, with greater variability in the zonal and meridional velocities as the flow organises itself into eddies, and a reduction in total transport. If a realization of a model is unable to get these aspects of the physical flow correct, then this will significantly reduce its ability to show a realistic biological signal or long-term response to climate change. Further south, beyond Durban, the application of no-slip conditions similarly causes the mean Agulhas Current to lie further offshore, making it much more able to simulate Natal Pulses.
Text
Quartly_et_al_NEMO_OcMod2013_postprint.pdf
- Accepted Manuscript
More information
Published date: March 2013
Keywords:
Indian Ocean: Mozambique Channel, NEMO, Spatial resolution, Boundary conditions, Stability, Natal Pulse (Current meandering)
Organisations:
Marine Systems Modelling, Marine Physics and Ocean Climate
Identifiers
Local EPrints ID: 346712
URI: http://eprints.soton.ac.uk/id/eprint/346712
ISSN: 1463-5003
PURE UUID: a84733e7-15d5-4557-8e05-727161a87381
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Date deposited: 07 Jan 2013 14:50
Last modified: 14 Mar 2024 12:40
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Contributors
Author:
G.D. Quartly
Author:
B.A. de Cuevas
Author:
A.C. Coward
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