Glacial ? interglacial atmospheric CO 2 change: a simple "hypsometric effect" on deep-ocean carbon sequestration?
International audience Given the magnitude and dynamism of the deep marine carbon reservoir, it is almost certain that past glacial ? interglacial fluctuations in atmospheric CO 2 have relied at least in part on changes in the carbon storage capacity of the deep sea. To date, physical ocean circulat...
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ftccsdartic:oai:HAL:hal-00298147v1 2023-11-12T04:26:43+01:00 Glacial ? interglacial atmospheric CO 2 change: a simple "hypsometric effect" on deep-ocean carbon sequestration? Skinner, L. C. Godwin Laboratory for Palaeoclimate Research Department of Earth Sciences Cambridge, UK University of Cambridge UK (CAM)-University of Cambridge UK (CAM) 2006-09-07 https://hal.science/hal-00298147 https://hal.science/hal-00298147/document https://hal.science/hal-00298147/file/cpd-2-711-2006.pdf en eng HAL CCSD European Geosciences Union (EGU) hal-00298147 https://hal.science/hal-00298147 https://hal.science/hal-00298147/document https://hal.science/hal-00298147/file/cpd-2-711-2006.pdf info:eu-repo/semantics/OpenAccess ISSN: 1814-9340 EISSN: 1814-9359 Climate of the Past Discussions https://hal.science/hal-00298147 Climate of the Past Discussions, 2006, 2 (5), pp.711-743 [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/article Journal articles 2006 ftccsdartic 2023-10-21T23:15:24Z International audience Given the magnitude and dynamism of the deep marine carbon reservoir, it is almost certain that past glacial ? interglacial fluctuations in atmospheric CO 2 have relied at least in part on changes in the carbon storage capacity of the deep sea. To date, physical ocean circulation mechanisms that have been proposed as viable explanations for glacial ? interglacial CO 2 change have focussed almost exclusively on dynamical or kinetic processes. Here, a simple mechanism is proposed for increasing the carbon storage capacity of the deep sea that operates via changes in the volume of southern-sourced deep-water filling the ocean basins, as dictated by the hypsometry of the ocean floor. It is proposed that a water-mass that occupies more than the bottom 3 km of the ocean will essentially determine the carbon content of the marine reservoir. Hence by filling this interval with southern-sourced deep-water (enriched in dissolved CO 2 due to its particular mode of formation) the amount of carbon sequestered in the deep sea may be greatly increased. A simple box-model is used to test this hypothesis, and to investigate its implications. It is suggested that up to 70% of the observed glacial ? interglacial CO 2 change might be explained by the replacement of northern-sourced deep-water below 2.5 km water depth by its southern counterpart. Most importantly, it is found that an increase in the volume of southern-sourced deep-water allows glacial CO 2 levels to be simulated easily with only modest changes in Southern Ocean biological export or overturning. If incorporated into the list of contributing factors to marine carbon sequestration, this mechanism may help to significantly reduce the "deficit" of explained glacial ? interglacial CO 2 change. Article in Journal/Newspaper Southern Ocean Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Southern Ocean |
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Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Skinner, L. C. Glacial ? interglacial atmospheric CO 2 change: a simple "hypsometric effect" on deep-ocean carbon sequestration? |
topic_facet |
[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience Given the magnitude and dynamism of the deep marine carbon reservoir, it is almost certain that past glacial ? interglacial fluctuations in atmospheric CO 2 have relied at least in part on changes in the carbon storage capacity of the deep sea. To date, physical ocean circulation mechanisms that have been proposed as viable explanations for glacial ? interglacial CO 2 change have focussed almost exclusively on dynamical or kinetic processes. Here, a simple mechanism is proposed for increasing the carbon storage capacity of the deep sea that operates via changes in the volume of southern-sourced deep-water filling the ocean basins, as dictated by the hypsometry of the ocean floor. It is proposed that a water-mass that occupies more than the bottom 3 km of the ocean will essentially determine the carbon content of the marine reservoir. Hence by filling this interval with southern-sourced deep-water (enriched in dissolved CO 2 due to its particular mode of formation) the amount of carbon sequestered in the deep sea may be greatly increased. A simple box-model is used to test this hypothesis, and to investigate its implications. It is suggested that up to 70% of the observed glacial ? interglacial CO 2 change might be explained by the replacement of northern-sourced deep-water below 2.5 km water depth by its southern counterpart. Most importantly, it is found that an increase in the volume of southern-sourced deep-water allows glacial CO 2 levels to be simulated easily with only modest changes in Southern Ocean biological export or overturning. If incorporated into the list of contributing factors to marine carbon sequestration, this mechanism may help to significantly reduce the "deficit" of explained glacial ? interglacial CO 2 change. |
author2 |
Godwin Laboratory for Palaeoclimate Research Department of Earth Sciences Cambridge, UK University of Cambridge UK (CAM)-University of Cambridge UK (CAM) |
format |
Article in Journal/Newspaper |
author |
Skinner, L. C. |
author_facet |
Skinner, L. C. |
author_sort |
Skinner, L. C. |
title |
Glacial ? interglacial atmospheric CO 2 change: a simple "hypsometric effect" on deep-ocean carbon sequestration? |
title_short |
Glacial ? interglacial atmospheric CO 2 change: a simple "hypsometric effect" on deep-ocean carbon sequestration? |
title_full |
Glacial ? interglacial atmospheric CO 2 change: a simple "hypsometric effect" on deep-ocean carbon sequestration? |
title_fullStr |
Glacial ? interglacial atmospheric CO 2 change: a simple "hypsometric effect" on deep-ocean carbon sequestration? |
title_full_unstemmed |
Glacial ? interglacial atmospheric CO 2 change: a simple "hypsometric effect" on deep-ocean carbon sequestration? |
title_sort |
glacial ? interglacial atmospheric co 2 change: a simple "hypsometric effect" on deep-ocean carbon sequestration? |
publisher |
HAL CCSD |
publishDate |
2006 |
url |
https://hal.science/hal-00298147 https://hal.science/hal-00298147/document https://hal.science/hal-00298147/file/cpd-2-711-2006.pdf |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
ISSN: 1814-9340 EISSN: 1814-9359 Climate of the Past Discussions https://hal.science/hal-00298147 Climate of the Past Discussions, 2006, 2 (5), pp.711-743 |
op_relation |
hal-00298147 https://hal.science/hal-00298147 https://hal.science/hal-00298147/document https://hal.science/hal-00298147/file/cpd-2-711-2006.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1782340597850308608 |