Precipitation regime influence on oxygen triple-isotope distributions in Antarctic precipitation and ice cores
The relative abundance of 17O in meteoric precipitation is usually reported in terms of the 17O-excess parameter. Variations of 17O-excess in Antarctic precipitation and ice cores have hitherto been attributed to normalised relative humidity changes at the moisture source region, or to the influence...
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ftnerc:oai:nora.nerc.ac.uk:518360 2023-05-15T13:49:34+02:00 Precipitation regime influence on oxygen triple-isotope distributions in Antarctic precipitation and ice cores Miller, Martin F. 2018-01 http://nora.nerc.ac.uk/id/eprint/518360/ https://www.sciencedirect.com/science/article/abs/pii/S0012821X17306039 unknown Elsevier Miller, Martin F. 2018 Precipitation regime influence on oxygen triple-isotope distributions in Antarctic precipitation and ice cores. Earth and Planetary Science Letters, 481. 316-327. https://doi.org/10.1016/j.epsl.2017.10.035 <https://doi.org/10.1016/j.epsl.2017.10.035> Publication - Article PeerReviewed 2018 ftnerc https://doi.org/10.1016/j.epsl.2017.10.035 2023-02-04T19:45:35Z The relative abundance of 17O in meteoric precipitation is usually reported in terms of the 17O-excess parameter. Variations of 17O-excess in Antarctic precipitation and ice cores have hitherto been attributed to normalised relative humidity changes at the moisture source region, or to the influence of a temperature-dependent supersaturation-controlled kinetic isotope effect during in-cloud ice formation below −20 °C. Neither mechanism, however, satisfactorily explains the large range of 17O-excess values reported from measurements. A different approach, based on the regression characteristics of 103ln(1+δ17O) versus 103ln(1+δ18O) , is applied here to previously published isotopic data sets. The analysis indicates that clear-sky precipitation (‘diamond dust’), which occurs widely in inland Antarctica, is characterised by an unusual relative abundance of 17O, distinct from that associated with cloud-derived, synoptic snowfall. Furthermore, this distinction appears to be largely preserved in the ice core record. The respective mass contributions to snowfall accumulation – on both temporal and spatial scales – provides the basis of a simple, first-order explanation for the observed oxygen triple-isotope ratio variations in Antarctic precipitation, surface snow and ice cores. Using this approach, it is shown that precipitation during the last major deglaciation, both in western Antarctica at the West Antarctic Ice Sheet (WAIS) Divide and at Vostok on the eastern Antarctic plateau, consisted essentially of diamond dust only, despite a large temperature differential (and thus different water vapour supersaturation conditions) at the two locations. In contrast, synoptic snowfall events dominate the accumulation record throughout the Holocene at both sites. Article in Journal/Newspaper Antarc* Antarctic Antarctica ice core Ice Sheet Natural Environment Research Council: NERC Open Research Archive Antarctic West Antarctic Ice Sheet Earth and Planetary Science Letters 481 316 327 |
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Natural Environment Research Council: NERC Open Research Archive |
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description |
The relative abundance of 17O in meteoric precipitation is usually reported in terms of the 17O-excess parameter. Variations of 17O-excess in Antarctic precipitation and ice cores have hitherto been attributed to normalised relative humidity changes at the moisture source region, or to the influence of a temperature-dependent supersaturation-controlled kinetic isotope effect during in-cloud ice formation below −20 °C. Neither mechanism, however, satisfactorily explains the large range of 17O-excess values reported from measurements. A different approach, based on the regression characteristics of 103ln(1+δ17O) versus 103ln(1+δ18O) , is applied here to previously published isotopic data sets. The analysis indicates that clear-sky precipitation (‘diamond dust’), which occurs widely in inland Antarctica, is characterised by an unusual relative abundance of 17O, distinct from that associated with cloud-derived, synoptic snowfall. Furthermore, this distinction appears to be largely preserved in the ice core record. The respective mass contributions to snowfall accumulation – on both temporal and spatial scales – provides the basis of a simple, first-order explanation for the observed oxygen triple-isotope ratio variations in Antarctic precipitation, surface snow and ice cores. Using this approach, it is shown that precipitation during the last major deglaciation, both in western Antarctica at the West Antarctic Ice Sheet (WAIS) Divide and at Vostok on the eastern Antarctic plateau, consisted essentially of diamond dust only, despite a large temperature differential (and thus different water vapour supersaturation conditions) at the two locations. In contrast, synoptic snowfall events dominate the accumulation record throughout the Holocene at both sites. |
format |
Article in Journal/Newspaper |
author |
Miller, Martin F. |
spellingShingle |
Miller, Martin F. Precipitation regime influence on oxygen triple-isotope distributions in Antarctic precipitation and ice cores |
author_facet |
Miller, Martin F. |
author_sort |
Miller, Martin F. |
title |
Precipitation regime influence on oxygen triple-isotope distributions in Antarctic precipitation and ice cores |
title_short |
Precipitation regime influence on oxygen triple-isotope distributions in Antarctic precipitation and ice cores |
title_full |
Precipitation regime influence on oxygen triple-isotope distributions in Antarctic precipitation and ice cores |
title_fullStr |
Precipitation regime influence on oxygen triple-isotope distributions in Antarctic precipitation and ice cores |
title_full_unstemmed |
Precipitation regime influence on oxygen triple-isotope distributions in Antarctic precipitation and ice cores |
title_sort |
precipitation regime influence on oxygen triple-isotope distributions in antarctic precipitation and ice cores |
publisher |
Elsevier |
publishDate |
2018 |
url |
http://nora.nerc.ac.uk/id/eprint/518360/ https://www.sciencedirect.com/science/article/abs/pii/S0012821X17306039 |
geographic |
Antarctic West Antarctic Ice Sheet |
geographic_facet |
Antarctic West Antarctic Ice Sheet |
genre |
Antarc* Antarctic Antarctica ice core Ice Sheet |
genre_facet |
Antarc* Antarctic Antarctica ice core Ice Sheet |
op_relation |
Miller, Martin F. 2018 Precipitation regime influence on oxygen triple-isotope distributions in Antarctic precipitation and ice cores. Earth and Planetary Science Letters, 481. 316-327. https://doi.org/10.1016/j.epsl.2017.10.035 <https://doi.org/10.1016/j.epsl.2017.10.035> |
op_doi |
https://doi.org/10.1016/j.epsl.2017.10.035 |
container_title |
Earth and Planetary Science Letters |
container_volume |
481 |
container_start_page |
316 |
op_container_end_page |
327 |
_version_ |
1766251713794146304 |