On the superposition of mean advective and eddy-induced transports in global ocean heat and salt budgets
Ocean thermal expansion is a large contributor to observed sea level rise, which is expected to continue into the future. However, large uncertainties exist in sea level projections among climate models, partially due to intermodel differences in ocean heat uptake and redistribution of buoyancy. Her...
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ftnerc:oai:nora.nerc.ac.uk:526714 2023-05-15T18:25:42+02:00 On the superposition of mean advective and eddy-induced transports in global ocean heat and salt budgets Dias, Fabio Boeira Domingues, C. M. Marsland, S. J. Griffies, S. M. Rintoul, S. R. Matear, R. Fiedler, R. 2020-01-08 text http://nora.nerc.ac.uk/id/eprint/526714/ https://nora.nerc.ac.uk/id/eprint/526714/1/untitled.pdf https://doi.org/10.1175/JCLI-D-19-0418.1 en eng https://nora.nerc.ac.uk/id/eprint/526714/1/untitled.pdf Dias, Fabio Boeira; Domingues, C. M. orcid:0000-0001-5100-4595 Marsland, S. J.; Griffies, S. M.; Rintoul, S. R.; Matear, R.; Fiedler, R. 2020 On the superposition of mean advective and eddy-induced transports in global ocean heat and salt budgets. Journal of Climate, 33 (3). 1121-1140. https://doi.org/10.1175/JCLI-D-19-0418.1 <https://doi.org/10.1175/JCLI-D-19-0418.1> Publication - Article PeerReviewed 2020 ftnerc https://doi.org/10.1175/JCLI-D-19-0418.1 2023-02-04T19:50:05Z Ocean thermal expansion is a large contributor to observed sea level rise, which is expected to continue into the future. However, large uncertainties exist in sea level projections among climate models, partially due to intermodel differences in ocean heat uptake and redistribution of buoyancy. Here, the mechanisms of vertical ocean heat and salt transport are investigated in quasi-steady-state model simulations using the Australian Community Climate and Earth-System Simulator Ocean Model (ACCESS-OM2). New insights into the net effect of key physical processes are gained within the superresidual transport (SRT) framework. In this framework, vertical tracer transport is dominated by downward fluxes associated with the large-scale ocean circulation and upward fluxes induced by mesoscale eddies, with two distinct physical regimes. In the upper ocean, where high-latitude water masses are formed by mixed layer processes, through cooling or salinification, the SRT counteracts those processes by transporting heat and salt downward. In contrast, in the ocean interior, the SRT opposes dianeutral diffusion via upward fluxes of heat and salt, with about 60% of the vertical heat transport occurring in the Southern Ocean. Overall, the SRT is largely responsible for removing newly formed water masses from the mixed layer into the ocean interior, where they are eroded by dianeutral diffusion. Unlike the classical advective–diffusive balance, dianeutral diffusion is bottom intensified above rough bottom topography, allowing an overturning cell to develop in alignment with recent theories. Implications are discussed for understanding the role of vertical tracer transport on the simulation of ocean climate and sea level. Article in Journal/Newspaper Southern Ocean Natural Environment Research Council: NERC Open Research Archive Southern Ocean Journal of Climate 33 3 1121 1140 |
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Open Polar |
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Natural Environment Research Council: NERC Open Research Archive |
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English |
description |
Ocean thermal expansion is a large contributor to observed sea level rise, which is expected to continue into the future. However, large uncertainties exist in sea level projections among climate models, partially due to intermodel differences in ocean heat uptake and redistribution of buoyancy. Here, the mechanisms of vertical ocean heat and salt transport are investigated in quasi-steady-state model simulations using the Australian Community Climate and Earth-System Simulator Ocean Model (ACCESS-OM2). New insights into the net effect of key physical processes are gained within the superresidual transport (SRT) framework. In this framework, vertical tracer transport is dominated by downward fluxes associated with the large-scale ocean circulation and upward fluxes induced by mesoscale eddies, with two distinct physical regimes. In the upper ocean, where high-latitude water masses are formed by mixed layer processes, through cooling or salinification, the SRT counteracts those processes by transporting heat and salt downward. In contrast, in the ocean interior, the SRT opposes dianeutral diffusion via upward fluxes of heat and salt, with about 60% of the vertical heat transport occurring in the Southern Ocean. Overall, the SRT is largely responsible for removing newly formed water masses from the mixed layer into the ocean interior, where they are eroded by dianeutral diffusion. Unlike the classical advective–diffusive balance, dianeutral diffusion is bottom intensified above rough bottom topography, allowing an overturning cell to develop in alignment with recent theories. Implications are discussed for understanding the role of vertical tracer transport on the simulation of ocean climate and sea level. |
format |
Article in Journal/Newspaper |
author |
Dias, Fabio Boeira Domingues, C. M. Marsland, S. J. Griffies, S. M. Rintoul, S. R. Matear, R. Fiedler, R. |
spellingShingle |
Dias, Fabio Boeira Domingues, C. M. Marsland, S. J. Griffies, S. M. Rintoul, S. R. Matear, R. Fiedler, R. On the superposition of mean advective and eddy-induced transports in global ocean heat and salt budgets |
author_facet |
Dias, Fabio Boeira Domingues, C. M. Marsland, S. J. Griffies, S. M. Rintoul, S. R. Matear, R. Fiedler, R. |
author_sort |
Dias, Fabio Boeira |
title |
On the superposition of mean advective and eddy-induced transports in global ocean heat and salt budgets |
title_short |
On the superposition of mean advective and eddy-induced transports in global ocean heat and salt budgets |
title_full |
On the superposition of mean advective and eddy-induced transports in global ocean heat and salt budgets |
title_fullStr |
On the superposition of mean advective and eddy-induced transports in global ocean heat and salt budgets |
title_full_unstemmed |
On the superposition of mean advective and eddy-induced transports in global ocean heat and salt budgets |
title_sort |
on the superposition of mean advective and eddy-induced transports in global ocean heat and salt budgets |
publishDate |
2020 |
url |
http://nora.nerc.ac.uk/id/eprint/526714/ https://nora.nerc.ac.uk/id/eprint/526714/1/untitled.pdf https://doi.org/10.1175/JCLI-D-19-0418.1 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
https://nora.nerc.ac.uk/id/eprint/526714/1/untitled.pdf Dias, Fabio Boeira; Domingues, C. M. orcid:0000-0001-5100-4595 Marsland, S. J.; Griffies, S. M.; Rintoul, S. R.; Matear, R.; Fiedler, R. 2020 On the superposition of mean advective and eddy-induced transports in global ocean heat and salt budgets. Journal of Climate, 33 (3). 1121-1140. https://doi.org/10.1175/JCLI-D-19-0418.1 <https://doi.org/10.1175/JCLI-D-19-0418.1> |
op_doi |
https://doi.org/10.1175/JCLI-D-19-0418.1 |
container_title |
Journal of Climate |
container_volume |
33 |
container_issue |
3 |
container_start_page |
1121 |
op_container_end_page |
1140 |
_version_ |
1766207301422678016 |