Planetary fertility during the past 400 ka based on the triple isotope composition of O 2 in trapped gases from the Vostok ice core
Abstract. 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...
Main Authors: | , |
---|---|
Other Authors: | |
Format: | Text |
Language: | English |
Published: |
2012
|
Subjects: | |
Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1035.1646 http://www.clim-past.net/8/1509/2012/cp-8-1509-2012.pdf |
id |
ftciteseerx:oai:CiteSeerX.psu:10.1.1.1035.1646 |
---|---|
record_format |
openpolar |
spelling |
ftciteseerx:oai:CiteSeerX.psu:10.1.1.1035.1646 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 Clim Past The Pennsylvania State University CiteSeerX Archives 2012 application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1035.1646 http://www.clim-past.net/8/1509/2012/cp-8-1509-2012.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1035.1646 http://www.clim-past.net/8/1509/2012/cp-8-1509-2012.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://www.clim-past.net/8/1509/2012/cp-8-1509-2012.pdf text 2012 ftciteseerx 2020-02-16T01:14:21Z Abstract. 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. Text ice core Unknown |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
ftciteseerx |
language |
English |
description |
Abstract. 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. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Clim Past |
spellingShingle |
Clim Past Planetary fertility during the past 400 ka based on the triple isotope composition of O 2 in trapped gases from the Vostok ice core |
author_facet |
Clim Past |
author_sort |
Clim |
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 |
publishDate |
2012 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1035.1646 http://www.clim-past.net/8/1509/2012/cp-8-1509-2012.pdf |
genre |
ice core |
genre_facet |
ice core |
op_source |
http://www.clim-past.net/8/1509/2012/cp-8-1509-2012.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1035.1646 http://www.clim-past.net/8/1509/2012/cp-8-1509-2012.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766029385358376960 |