Planetary fertility during the past 400 ka based on the triple isotope composition of O 2 in trapped gases from the Vostok ice core
The productivity of the biosphere leaves its imprint on the isotopic composition of atmospheric oxygen. Ultimately, atmospheric oxygen, through photosynthesis, originates from seawater. Fractionations during the passage from seawater to atmospheric O 2 and during respiration affect δ 17 O approximat...
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ftdoajarticles:oai:doaj.org/article:5f31ab729b9c47b19a01649a5f3d511b 2023-05-15T16:39:01+02:00 Planetary fertility during the past 400 ka based on the triple isotope composition of O 2 in trapped gases from the Vostok ice core J. C. von Fischer B. Barnett T. Blunier M. L. Bender 2012-10-01T00:00:00Z https://doi.org/10.5194/cp-8-1509-2012 https://doaj.org/article/5f31ab729b9c47b19a01649a5f3d511b EN eng Copernicus Publications http://www.clim-past.net/8/1509/2012/cp-8-1509-2012.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-8-1509-2012 1814-9324 1814-9332 https://doaj.org/article/5f31ab729b9c47b19a01649a5f3d511b Climate of the Past, Vol 8, Iss 5, Pp 1509-1526 (2012) Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 article 2012 ftdoajarticles https://doi.org/10.5194/cp-8-1509-2012 2022-12-31T13:07:43Z The productivity of the biosphere leaves its imprint on the isotopic composition of atmospheric oxygen. Ultimately, atmospheric oxygen, through photosynthesis, originates from seawater. Fractionations during the passage from seawater to atmospheric O 2 and during respiration affect δ 17 O approximately half as much as δ 18 O. An "anomalous" (also termed mass independent) fractionation process changes δ 17 O about 1.7 times as much as δ 18 O during isotope exchange between O 2 and CO 2 in the stratosphere. The relative rates of biological O 2 production and stratospheric processing determine the relationship between δ 17 O and δ 18 O of O 2 in the atmosphere. Variations of this relationship thus allow us to estimate changes in the rate of O 2 production by photosynthesis versus the rate of O 2 –CO 2 isotope exchange in the stratosphere. However, the analysis of the 17 O anomaly is complicated because each hydrological and biological process fractionates δ 17 O and δ 18 O in slightly different proportions. In this study we present O 2 isotope data covering the last 400 ka (thousand years) from the Vostok ice core. We reconstruct oxygen productivities from the triple isotope composition of atmospheric oxygen with a box model. Our steady state model for the oxygen cycle takes into account fractionation during photosynthesis and respiration by the land and ocean biosphere, fractionation during the hydrologic cycle, and fractionation when oxygen passes through the stratosphere. We consider changes of fractionation factors linked to climate variations, taking into account the span of estimates of the main factors affecting our calculations. We find that ocean oxygen productivity was within 20% of the modern value throughout the last 400 ka. Given the presumed reduction in terrestrial oxygen productivity, the total oxygen production during glacials was likely reduced. Article in Journal/Newspaper ice core Directory of Open Access Journals: DOAJ Articles Climate of the Past 8 5 1509 1526 |
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Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
language |
English |
topic |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
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Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 J. C. von Fischer B. Barnett T. Blunier M. L. Bender Planetary fertility during the past 400 ka based on the triple isotope composition of O 2 in trapped gases from the Vostok ice core |
topic_facet |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
description |
The productivity of the biosphere leaves its imprint on the isotopic composition of atmospheric oxygen. Ultimately, atmospheric oxygen, through photosynthesis, originates from seawater. Fractionations during the passage from seawater to atmospheric O 2 and during respiration affect δ 17 O approximately half as much as δ 18 O. An "anomalous" (also termed mass independent) fractionation process changes δ 17 O about 1.7 times as much as δ 18 O during isotope exchange between O 2 and CO 2 in the stratosphere. The relative rates of biological O 2 production and stratospheric processing determine the relationship between δ 17 O and δ 18 O of O 2 in the atmosphere. Variations of this relationship thus allow us to estimate changes in the rate of O 2 production by photosynthesis versus the rate of O 2 –CO 2 isotope exchange in the stratosphere. However, the analysis of the 17 O anomaly is complicated because each hydrological and biological process fractionates δ 17 O and δ 18 O in slightly different proportions. In this study we present O 2 isotope data covering the last 400 ka (thousand years) from the Vostok ice core. We reconstruct oxygen productivities from the triple isotope composition of atmospheric oxygen with a box model. Our steady state model for the oxygen cycle takes into account fractionation during photosynthesis and respiration by the land and ocean biosphere, fractionation during the hydrologic cycle, and fractionation when oxygen passes through the stratosphere. We consider changes of fractionation factors linked to climate variations, taking into account the span of estimates of the main factors affecting our calculations. We find that ocean oxygen productivity was within 20% of the modern value throughout the last 400 ka. Given the presumed reduction in terrestrial oxygen productivity, the total oxygen production during glacials was likely reduced. |
format |
Article in Journal/Newspaper |
author |
J. C. von Fischer B. Barnett T. Blunier M. L. Bender |
author_facet |
J. C. von Fischer B. Barnett T. Blunier M. L. Bender |
author_sort |
J. C. von Fischer |
title |
Planetary fertility during the past 400 ka based on the triple isotope composition of O 2 in trapped gases from the Vostok ice core |
title_short |
Planetary fertility during the past 400 ka based on the triple isotope composition of O 2 in trapped gases from the Vostok ice core |
title_full |
Planetary fertility during the past 400 ka based on the triple isotope composition of O 2 in trapped gases from the Vostok ice core |
title_fullStr |
Planetary fertility during the past 400 ka based on the triple isotope composition of O 2 in trapped gases from the Vostok ice core |
title_full_unstemmed |
Planetary fertility during the past 400 ka based on the triple isotope composition of O 2 in trapped gases from the Vostok ice core |
title_sort |
planetary fertility during the past 400 ka based on the triple isotope composition of o 2 in trapped gases from the vostok ice core |
publisher |
Copernicus Publications |
publishDate |
2012 |
url |
https://doi.org/10.5194/cp-8-1509-2012 https://doaj.org/article/5f31ab729b9c47b19a01649a5f3d511b |
genre |
ice core |
genre_facet |
ice core |
op_source |
Climate of the Past, Vol 8, Iss 5, Pp 1509-1526 (2012) |
op_relation |
http://www.clim-past.net/8/1509/2012/cp-8-1509-2012.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-8-1509-2012 1814-9324 1814-9332 https://doaj.org/article/5f31ab729b9c47b19a01649a5f3d511b |
op_doi |
https://doi.org/10.5194/cp-8-1509-2012 |
container_title |
Climate of the Past |
container_volume |
8 |
container_issue |
5 |
container_start_page |
1509 |
op_container_end_page |
1526 |
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1766029381367496704 |