The Global ocean circulation during 1992-1997, estimated from ocean observations and a general circulation model
The Global ocean circulation during 1992-1997, estimated from ocean observations and a general circulation model
We discuss the three-dimensional oceanic state estimated for the period 1992- 1997 as it results from bringing together large-scale ocean data sets with a general circulation model. To bring the model into close agreement with ocean data, its initial temperature and salinity conditions where changed as well as the time-dependent surface fluxes of momentum, heat and freshwater. Resulting changes of those control fields are largely consistent with accepted uncertainties in the hydrographic climatology and meteorological analyses. Our results show that the assimilation procedure is able to correct for the traditional shortcomings of the flow field by changing the surface boundary conditions. Changes of the resulting flow field are predominantly on the gyre scale and affect many features which are often poorly simulated in traditional numerical simulations, such as the strengths of the Gulf Stream and its extension, the Azores Current and the anticyclonic circulation associated with the Labrador Sea. A detailed test of the results and their consistency with prior error assumptions shows that the constrained model has moved considerably closer to those observations which have been imposed as constraints, but also to independent data from the World Ocean Circulation Experiment not used in the assimilation procedure. In some regions where the comparisons remain indeterminate, not enough ocean observations are available. And in such situations, it is difficult to ascribe the residuals to either the model or the observations. We conclude from this experiment that we can find an acceptable solution to the global time-dependent ocean state estimation problem. As the estimates improve through the evolution of numerical models, computer power increases, and better assimilation schemes, improved and routine estimates will become possible.
ocean circulation, mathematical models, ocean currents, ocean model
1-27
Stammer, D.
2ace512d-2e95-4ffe-9fcc-8af6c1b5fcf2
Wunsch, C.
cc7ca024-feaa-4733-9c9c-8dd935befc6c
Giering, R.
681c7e29-c98a-4167-b464-66eb18c3ccf5
Eckert, C.
538730d8-63bd-4924-9d54-9341272a1794
Heimbach, P.
a5fd5b9f-8209-4c28-a064-729c30ba8a29
Marotzke, J.
6047bfd1-68a3-4abe-95ce-e1df9a56ce76
Adcroft, A.
513a48ba-1114-4ca9-a536-7cd905a8b1ce
Hill, C.N.
16643f8b-564c-43a4-ac1f-4635d352a700
Marshall, J.
6592d20b-7322-46ca-a8b2-27bb7b986fae
September 2002
Stammer, D.
2ace512d-2e95-4ffe-9fcc-8af6c1b5fcf2
Wunsch, C.
cc7ca024-feaa-4733-9c9c-8dd935befc6c
Giering, R.
681c7e29-c98a-4167-b464-66eb18c3ccf5
Eckert, C.
538730d8-63bd-4924-9d54-9341272a1794
Heimbach, P.
a5fd5b9f-8209-4c28-a064-729c30ba8a29
Marotzke, J.
6047bfd1-68a3-4abe-95ce-e1df9a56ce76
Adcroft, A.
513a48ba-1114-4ca9-a536-7cd905a8b1ce
Hill, C.N.
16643f8b-564c-43a4-ac1f-4635d352a700
Marshall, J.
6592d20b-7322-46ca-a8b2-27bb7b986fae
Stammer, D., Wunsch, C., Giering, R., Eckert, C., Heimbach, P., Marotzke, J., Adcroft, A., Hill, C.N. and Marshall, J.
(2002)
The Global ocean circulation during 1992-1997, estimated from ocean observations and a general circulation model.
Journal of Geophysical Research, 107 (C9), , [3118].
(doi:10.1029/2001JC000888).
Abstract
We discuss the three-dimensional oceanic state estimated for the period 1992- 1997 as it results from bringing together large-scale ocean data sets with a general circulation model. To bring the model into close agreement with ocean data, its initial temperature and salinity conditions where changed as well as the time-dependent surface fluxes of momentum, heat and freshwater. Resulting changes of those control fields are largely consistent with accepted uncertainties in the hydrographic climatology and meteorological analyses. Our results show that the assimilation procedure is able to correct for the traditional shortcomings of the flow field by changing the surface boundary conditions. Changes of the resulting flow field are predominantly on the gyre scale and affect many features which are often poorly simulated in traditional numerical simulations, such as the strengths of the Gulf Stream and its extension, the Azores Current and the anticyclonic circulation associated with the Labrador Sea. A detailed test of the results and their consistency with prior error assumptions shows that the constrained model has moved considerably closer to those observations which have been imposed as constraints, but also to independent data from the World Ocean Circulation Experiment not used in the assimilation procedure. In some regions where the comparisons remain indeterminate, not enough ocean observations are available. And in such situations, it is difficult to ascribe the residuals to either the model or the observations. We conclude from this experiment that we can find an acceptable solution to the global time-dependent ocean state estimation problem. As the estimates improve through the evolution of numerical models, computer power increases, and better assimilation schemes, improved and routine estimates will become possible.
Text
Ecco_paper_1_rev.pdf
- Other
More information
Published date: September 2002
Keywords:
ocean circulation, mathematical models, ocean currents, ocean model
Identifiers
Local EPrints ID: 214
URI: http://eprints.soton.ac.uk/id/eprint/214
ISSN: 0148-0227
PURE UUID: b2b27bf1-dd2d-4736-9163-5b2ffc2f5fbc
Catalogue record
Date deposited: 07 Nov 2003
Last modified: 15 Mar 2024 04:37
Export record
Altmetrics
Contributors
Author:
D. Stammer
Author:
C. Wunsch
Author:
R. Giering
Author:
C. Eckert
Author:
P. Heimbach
Author:
J. Marotzke
Author:
A. Adcroft
Author:
C.N. Hill
Author:
J. Marshall
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics