Seasonal and mesoscale variability of oceanic transport of anthropogenic CO 2
International audience Estimates of the ocean's large-scale transport of anthropogenic CO 2 are based on one-time hydrographic sections, but the temporal variability of this transport has not been investigated. The aim of this study is to evaluate how the seasonal and mesoscale variability affe...
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ftceafr:oai:HAL:hal-04113543v1 2024-09-09T19:56:50+00:00 Seasonal and mesoscale variability of oceanic transport of anthropogenic CO 2 Lachkar, Z. Orr, J. C. Dutay, J. -C. Laboratoire des Sciences du Climat et de l'Environnement (LSCE) Commissariat à l'énergie atomique et aux énergies alternatives (CEA) 2009 https://hal.science/hal-04113543 https://doi.org/10.5194/bg-6-2509-200910.5194/bgd-6-4233-2009 en eng HAL CCSD European Geosciences Union info:eu-repo/semantics/altIdentifier/doi/10.5194/bg-6-2509-200910.5194/bgd-6-4233-2009 hal-04113543 https://hal.science/hal-04113543 BIBCODE: 2009BGeo.6.2509L doi:10.5194/bg-6-2509-200910.5194/bgd-6-4233-2009 ISSN: 1726-4170 EISSN: 1726-4189 Biogeosciences https://hal.science/hal-04113543 Biogeosciences, 2009, 6, pp.2509-2523. ⟨10.5194/bg-6-2509-200910.5194/bgd-6-4233-2009⟩ Earth Science [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2009 ftceafr https://doi.org/10.5194/bg-6-2509-200910.5194/bgd-6-4233-2009 2024-07-22T13:06:21Z International audience Estimates of the ocean's large-scale transport of anthropogenic CO 2 are based on one-time hydrographic sections, but the temporal variability of this transport has not been investigated. The aim of this study is to evaluate how the seasonal and mesoscale variability affect data-based estimates of anthropogenic CO 2 transport. To diagnose this variability, we made a global anthropogenic CO 2 simulation using an eddy-permitting version of the coupled ocean sea-ice model ORCA-LIM. As for heat transport, the seasonally varying transport of anthropogenic CO 2 is largest within 20° of the equator and shows secondary maxima in the subtropics. Ekman transport generally drives most of the seasonal variability, but the contribution of the vertical shear becomes important near the equator and in the Southern Ocean. Mesoscale variabilty contributes to the annual-mean transport of both heat and anthropogenic CO 2 with strong poleward transport in the Southern Ocean and equatorward transport in the tropics. This "rectified" eddy transport is largely baroclinic in the tropics and barotropic in the Southern Ocean due to a larger contribution from standing eddies. Our analysis revealed that most previous hydrographic estimates of meridional transport of anthropogenic CO 2 are severely biased because they neglect temporal fluctuations due to non-Ekman velocity variations. In each of the three major ocean basins, this bias is largest near the equator and in the high southern latitudes. In the subtropical North Atlantic, where most of the hydrographic-based estimates have been focused, this uncertainty represents up to 20% and 30% of total meridional transport of heat and CO 2 . Generally though, outside the tropics and Southern Ocean, there are only small variations in meridional transport due to seasonal variations in tracer fields and time variations in eddy transport. For the North Atlantic, eddy variability accounts for up to 10% and 15% of the total transport of heat and CO 2 . This component is not ... Article in Journal/Newspaper North Atlantic Orca Sea ice Southern Ocean HAL-CEA (Commissariat à l'énergie atomique et aux énergies alternatives) Southern Ocean |
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Open Polar |
collection |
HAL-CEA (Commissariat à l'énergie atomique et aux énergies alternatives) |
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ftceafr |
language |
English |
topic |
Earth Science [SDU]Sciences of the Universe [physics] |
spellingShingle |
Earth Science [SDU]Sciences of the Universe [physics] Lachkar, Z. Orr, J. C. Dutay, J. -C. Seasonal and mesoscale variability of oceanic transport of anthropogenic CO 2 |
topic_facet |
Earth Science [SDU]Sciences of the Universe [physics] |
description |
International audience Estimates of the ocean's large-scale transport of anthropogenic CO 2 are based on one-time hydrographic sections, but the temporal variability of this transport has not been investigated. The aim of this study is to evaluate how the seasonal and mesoscale variability affect data-based estimates of anthropogenic CO 2 transport. To diagnose this variability, we made a global anthropogenic CO 2 simulation using an eddy-permitting version of the coupled ocean sea-ice model ORCA-LIM. As for heat transport, the seasonally varying transport of anthropogenic CO 2 is largest within 20° of the equator and shows secondary maxima in the subtropics. Ekman transport generally drives most of the seasonal variability, but the contribution of the vertical shear becomes important near the equator and in the Southern Ocean. Mesoscale variabilty contributes to the annual-mean transport of both heat and anthropogenic CO 2 with strong poleward transport in the Southern Ocean and equatorward transport in the tropics. This "rectified" eddy transport is largely baroclinic in the tropics and barotropic in the Southern Ocean due to a larger contribution from standing eddies. Our analysis revealed that most previous hydrographic estimates of meridional transport of anthropogenic CO 2 are severely biased because they neglect temporal fluctuations due to non-Ekman velocity variations. In each of the three major ocean basins, this bias is largest near the equator and in the high southern latitudes. In the subtropical North Atlantic, where most of the hydrographic-based estimates have been focused, this uncertainty represents up to 20% and 30% of total meridional transport of heat and CO 2 . Generally though, outside the tropics and Southern Ocean, there are only small variations in meridional transport due to seasonal variations in tracer fields and time variations in eddy transport. For the North Atlantic, eddy variability accounts for up to 10% and 15% of the total transport of heat and CO 2 . This component is not ... |
author2 |
Laboratoire des Sciences du Climat et de l'Environnement (LSCE) Commissariat à l'énergie atomique et aux énergies alternatives (CEA) |
format |
Article in Journal/Newspaper |
author |
Lachkar, Z. Orr, J. C. Dutay, J. -C. |
author_facet |
Lachkar, Z. Orr, J. C. Dutay, J. -C. |
author_sort |
Lachkar, Z. |
title |
Seasonal and mesoscale variability of oceanic transport of anthropogenic CO 2 |
title_short |
Seasonal and mesoscale variability of oceanic transport of anthropogenic CO 2 |
title_full |
Seasonal and mesoscale variability of oceanic transport of anthropogenic CO 2 |
title_fullStr |
Seasonal and mesoscale variability of oceanic transport of anthropogenic CO 2 |
title_full_unstemmed |
Seasonal and mesoscale variability of oceanic transport of anthropogenic CO 2 |
title_sort |
seasonal and mesoscale variability of oceanic transport of anthropogenic co 2 |
publisher |
HAL CCSD |
publishDate |
2009 |
url |
https://hal.science/hal-04113543 https://doi.org/10.5194/bg-6-2509-200910.5194/bgd-6-4233-2009 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
North Atlantic Orca Sea ice Southern Ocean |
genre_facet |
North Atlantic Orca Sea ice Southern Ocean |
op_source |
ISSN: 1726-4170 EISSN: 1726-4189 Biogeosciences https://hal.science/hal-04113543 Biogeosciences, 2009, 6, pp.2509-2523. ⟨10.5194/bg-6-2509-200910.5194/bgd-6-4233-2009⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/bg-6-2509-200910.5194/bgd-6-4233-2009 hal-04113543 https://hal.science/hal-04113543 BIBCODE: 2009BGeo.6.2509L doi:10.5194/bg-6-2509-200910.5194/bgd-6-4233-2009 |
op_doi |
https://doi.org/10.5194/bg-6-2509-200910.5194/bgd-6-4233-2009 |
_version_ |
1809927678820614144 |