Algal biomarkers as a proxy for p CO 2 : Constraints from late quaternary sapropels in the eastern Mediterranean
Records of carbon dioxide concentrations (partial pressure expressed as p CO 2 ) over Earth’s history provide trends that arecritical to understand our changing world. To better constrain p CO 2 estimations, here we test organic p CO 2 proxies against the direct measurements of p CO 2 recorded in ic...
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ftnioz:oai:imis.nioz.nl:331244 2023-05-15T16:38:52+02:00 Algal biomarkers as a proxy for p CO 2 : Constraints from late quaternary sapropels in the eastern Mediterranean Witkowski, C.R. van der Meer, M.T.J. Blais, B. Sinninghe Damsté, J.S. Schouten, S. 2020 application/pdf https://www.vliz.be/imisdocs/publications/96/355596.pdf en eng info:eu-repo/semantics/altIdentifier/wos/000599850700010 info:eu-repo/semantics/altIdentifier/doi/.org/10.1016/j.orggeochem.2020.104123 https://www.vliz.be/imisdocs/publications/96/355596.pdf info:eu-repo/semantics/openAccess %3Ci%3EOrg.+Geochem.+150%3C%2Fi%3E%3A+104123.+%3Ca+href%3D%22https%3A%2F%2Fdoi.org%2F10.1016%2Fj.orggeochem.2020.104123%22+target%3D%22_blank%22%3Ehttps%3A%2F%2Fdoi.org%2F10.1016%2Fj.orggeochem.2020.104123%3C%2Fa%3E info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2020 ftnioz https://doi.org/10.1016/j.orggeochem.2020.104123 2022-05-01T14:12:59Z Records of carbon dioxide concentrations (partial pressure expressed as p CO 2 ) over Earth’s history provide trends that arecritical to understand our changing world. To better constrain p CO 2 estimations, here we test organic p CO 2 proxies against the direct measurements of p CO 2 recorded in ice cores. Based on the concept of stable carbon isotopic fractionation due to photosynthetic CO 2 fixation (Ɛ p ), we use the stable carbon isotopic composition (δ 13 C) of the recently proposed biomarker phytol (from all photoautotrophs), as well as the conventionally used alkenone biomarkers (from specific species) for comparison, to reconstruct p CO 2 over several Quaternary sapropel formation periods (S1, S3, S4, and S5) in the eastern Mediterranean Sea. The reconstructed p CO 2 values are within error of the ice core values but consistently exceed the ice core values by ca. 100 µatm. This offset corresponds with atmospheric disequilibrium of present day CO 2[aq] concentrations in the Mediterranean Sea from global p CO 2 , equivalent to ca. 100 µatm, although p CO 2 estimates derived from individual horizons within each sapropel do not covary with the ice core values. This may possibly be due to greater variability in local CO 2[aq] concentration changes in the Mediterranean, as compared with the global average p CO 2 , or possibly due to biases in the proxy, such as variable growth rate or carbon-concentrating mechanisms. Thus, the offset is likely a combination of physiological or environmental factors.Nevertheless, our results demonstrate that alkenone- and phytol-based p CO 2 proxies yield statistically similar estimations ( P -value = 0.02, Pearson’s r -value = 0.56), and yield reasonable absolute estimations although with relatively large uncertainties (±100 µatm). Article in Journal/Newspaper ice core NIOZ Repository (Royal Netherlands Institute for Sea Research) Organic Geochemistry 150 104123 |
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Open Polar |
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NIOZ Repository (Royal Netherlands Institute for Sea Research) |
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ftnioz |
language |
English |
description |
Records of carbon dioxide concentrations (partial pressure expressed as p CO 2 ) over Earth’s history provide trends that arecritical to understand our changing world. To better constrain p CO 2 estimations, here we test organic p CO 2 proxies against the direct measurements of p CO 2 recorded in ice cores. Based on the concept of stable carbon isotopic fractionation due to photosynthetic CO 2 fixation (Ɛ p ), we use the stable carbon isotopic composition (δ 13 C) of the recently proposed biomarker phytol (from all photoautotrophs), as well as the conventionally used alkenone biomarkers (from specific species) for comparison, to reconstruct p CO 2 over several Quaternary sapropel formation periods (S1, S3, S4, and S5) in the eastern Mediterranean Sea. The reconstructed p CO 2 values are within error of the ice core values but consistently exceed the ice core values by ca. 100 µatm. This offset corresponds with atmospheric disequilibrium of present day CO 2[aq] concentrations in the Mediterranean Sea from global p CO 2 , equivalent to ca. 100 µatm, although p CO 2 estimates derived from individual horizons within each sapropel do not covary with the ice core values. This may possibly be due to greater variability in local CO 2[aq] concentration changes in the Mediterranean, as compared with the global average p CO 2 , or possibly due to biases in the proxy, such as variable growth rate or carbon-concentrating mechanisms. Thus, the offset is likely a combination of physiological or environmental factors.Nevertheless, our results demonstrate that alkenone- and phytol-based p CO 2 proxies yield statistically similar estimations ( P -value = 0.02, Pearson’s r -value = 0.56), and yield reasonable absolute estimations although with relatively large uncertainties (±100 µatm). |
format |
Article in Journal/Newspaper |
author |
Witkowski, C.R. van der Meer, M.T.J. Blais, B. Sinninghe Damsté, J.S. Schouten, S. |
spellingShingle |
Witkowski, C.R. van der Meer, M.T.J. Blais, B. Sinninghe Damsté, J.S. Schouten, S. Algal biomarkers as a proxy for p CO 2 : Constraints from late quaternary sapropels in the eastern Mediterranean |
author_facet |
Witkowski, C.R. van der Meer, M.T.J. Blais, B. Sinninghe Damsté, J.S. Schouten, S. |
author_sort |
Witkowski, C.R. |
title |
Algal biomarkers as a proxy for p CO 2 : Constraints from late quaternary sapropels in the eastern Mediterranean |
title_short |
Algal biomarkers as a proxy for p CO 2 : Constraints from late quaternary sapropels in the eastern Mediterranean |
title_full |
Algal biomarkers as a proxy for p CO 2 : Constraints from late quaternary sapropels in the eastern Mediterranean |
title_fullStr |
Algal biomarkers as a proxy for p CO 2 : Constraints from late quaternary sapropels in the eastern Mediterranean |
title_full_unstemmed |
Algal biomarkers as a proxy for p CO 2 : Constraints from late quaternary sapropels in the eastern Mediterranean |
title_sort |
algal biomarkers as a proxy for p co 2 : constraints from late quaternary sapropels in the eastern mediterranean |
publishDate |
2020 |
url |
https://www.vliz.be/imisdocs/publications/96/355596.pdf |
genre |
ice core |
genre_facet |
ice core |
op_source |
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op_relation |
info:eu-repo/semantics/altIdentifier/wos/000599850700010 info:eu-repo/semantics/altIdentifier/doi/.org/10.1016/j.orggeochem.2020.104123 https://www.vliz.be/imisdocs/publications/96/355596.pdf |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1016/j.orggeochem.2020.104123 |
container_title |
Organic Geochemistry |
container_volume |
150 |
container_start_page |
104123 |
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