Improving continuous-flow analysis of triple oxygen isotopes in ice cores: insights from replicate measurements
Stable water isotope measurements from polar ice cores provide high-resolution information about past hydrologic conditions and are therefore important for understanding earth's climate system. Routine high-resolution measurements of δ 18 O, δ D, and deuterium excess are made by continuous-flow...
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ftdoajarticles:oai:doaj.org/article:adc6676aade14b2986a1da03afe070e8 2023-05-15T16:30:12+02:00 Improving continuous-flow analysis of triple oxygen isotopes in ice cores: insights from replicate measurements L. Davidge E. J. Steig A. J. Schauer 2022-12-01T00:00:00Z https://doi.org/10.5194/amt-15-7337-2022 https://doaj.org/article/adc6676aade14b2986a1da03afe070e8 EN eng Copernicus Publications https://amt.copernicus.org/articles/15/7337/2022/amt-15-7337-2022.pdf https://doaj.org/toc/1867-1381 https://doaj.org/toc/1867-8548 doi:10.5194/amt-15-7337-2022 1867-1381 1867-8548 https://doaj.org/article/adc6676aade14b2986a1da03afe070e8 Atmospheric Measurement Techniques, Vol 15, Pp 7337-7351 (2022) Environmental engineering TA170-171 Earthwork. Foundations TA715-787 article 2022 ftdoajarticles https://doi.org/10.5194/amt-15-7337-2022 2022-12-30T19:33:22Z Stable water isotope measurements from polar ice cores provide high-resolution information about past hydrologic conditions and are therefore important for understanding earth's climate system. Routine high-resolution measurements of δ 18 O, δ D, and deuterium excess are made by continuous-flow analysis (CFA) methods that include laser spectrometers. Cavity ring-down laser spectroscopy (CRDS) allows for simultaneous measurements of all stable water isotopes, including δ 17 O and 17 O excess ( Δ 17 O); however, the limitations of CFA methodologies for Δ 17 O are not well understood. Here, we describe a measurement methodology for all stable water isotopes that uses a CFA system coupled with a CRDS instrument. We make repeated measurements of an ice-core section using this method to explore the reproducibility of CFA–CRDS measurements for Δ 17 O. Our data demonstrate that the CFA–CRDS method can make high-precision measurements of Δ 17 O ( < 5 per meg at averaging times > 3000 s). We show that the variations within our CFA ice-core measurements are well matched in magnitude and timing by the variations within the discrete CRDS measurements; we find that calibration offsets generate most of the variability among the replicate datasets. When these offsets are accounted for, the precision of CFA–CRDS ice-core data for Δ 17 O is as good as the precision of Δ 17 O for continuous reference water measurements. We demonstrate that this method can detect seasonal variability in Δ 17 O in Greenland ice, and our work suggests that the measurement resolution of CFA–CRDS is largely defined by the melt and measurement rate. We suggest that CFA–CRDS has the potential to increase measurement resolution of δ 17 O and Δ 17 O in ice cores, but also highlight the importance of developing calibration strategies with attention to Δ 17 O. Article in Journal/Newspaper Greenland ice core Directory of Open Access Journals: DOAJ Articles Greenland Atmospheric Measurement Techniques 15 24 7337 7351 |
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Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental engineering TA170-171 Earthwork. Foundations TA715-787 |
spellingShingle |
Environmental engineering TA170-171 Earthwork. Foundations TA715-787 L. Davidge E. J. Steig A. J. Schauer Improving continuous-flow analysis of triple oxygen isotopes in ice cores: insights from replicate measurements |
topic_facet |
Environmental engineering TA170-171 Earthwork. Foundations TA715-787 |
description |
Stable water isotope measurements from polar ice cores provide high-resolution information about past hydrologic conditions and are therefore important for understanding earth's climate system. Routine high-resolution measurements of δ 18 O, δ D, and deuterium excess are made by continuous-flow analysis (CFA) methods that include laser spectrometers. Cavity ring-down laser spectroscopy (CRDS) allows for simultaneous measurements of all stable water isotopes, including δ 17 O and 17 O excess ( Δ 17 O); however, the limitations of CFA methodologies for Δ 17 O are not well understood. Here, we describe a measurement methodology for all stable water isotopes that uses a CFA system coupled with a CRDS instrument. We make repeated measurements of an ice-core section using this method to explore the reproducibility of CFA–CRDS measurements for Δ 17 O. Our data demonstrate that the CFA–CRDS method can make high-precision measurements of Δ 17 O ( < 5 per meg at averaging times > 3000 s). We show that the variations within our CFA ice-core measurements are well matched in magnitude and timing by the variations within the discrete CRDS measurements; we find that calibration offsets generate most of the variability among the replicate datasets. When these offsets are accounted for, the precision of CFA–CRDS ice-core data for Δ 17 O is as good as the precision of Δ 17 O for continuous reference water measurements. We demonstrate that this method can detect seasonal variability in Δ 17 O in Greenland ice, and our work suggests that the measurement resolution of CFA–CRDS is largely defined by the melt and measurement rate. We suggest that CFA–CRDS has the potential to increase measurement resolution of δ 17 O and Δ 17 O in ice cores, but also highlight the importance of developing calibration strategies with attention to Δ 17 O. |
format |
Article in Journal/Newspaper |
author |
L. Davidge E. J. Steig A. J. Schauer |
author_facet |
L. Davidge E. J. Steig A. J. Schauer |
author_sort |
L. Davidge |
title |
Improving continuous-flow analysis of triple oxygen isotopes in ice cores: insights from replicate measurements |
title_short |
Improving continuous-flow analysis of triple oxygen isotopes in ice cores: insights from replicate measurements |
title_full |
Improving continuous-flow analysis of triple oxygen isotopes in ice cores: insights from replicate measurements |
title_fullStr |
Improving continuous-flow analysis of triple oxygen isotopes in ice cores: insights from replicate measurements |
title_full_unstemmed |
Improving continuous-flow analysis of triple oxygen isotopes in ice cores: insights from replicate measurements |
title_sort |
improving continuous-flow analysis of triple oxygen isotopes in ice cores: insights from replicate measurements |
publisher |
Copernicus Publications |
publishDate |
2022 |
url |
https://doi.org/10.5194/amt-15-7337-2022 https://doaj.org/article/adc6676aade14b2986a1da03afe070e8 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland ice core |
genre_facet |
Greenland ice core |
op_source |
Atmospheric Measurement Techniques, Vol 15, Pp 7337-7351 (2022) |
op_relation |
https://amt.copernicus.org/articles/15/7337/2022/amt-15-7337-2022.pdf https://doaj.org/toc/1867-1381 https://doaj.org/toc/1867-8548 doi:10.5194/amt-15-7337-2022 1867-1381 1867-8548 https://doaj.org/article/adc6676aade14b2986a1da03afe070e8 |
op_doi |
https://doi.org/10.5194/amt-15-7337-2022 |
container_title |
Atmospheric Measurement Techniques |
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15 |
container_issue |
24 |
container_start_page |
7337 |
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7351 |
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1766019918162034688 |