Sea ice control on winter subsurface temperatures of the North Iceland Shelf during the Little Ice Age: A TEX 86 calibration case study
<jats:title>Abstract</jats:title><jats:p>Holocene paleoceanographic reconstructions along the North Iceland Shelf have employed a variety of sea surface temperature and sea ice proxies. However, these surface proxies tend to have a seasonal bias toward spring/summer and thus only p...
Published in: | Paleoceanography and Paleoclimatology |
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Format: | Article in Journal/Newspaper |
Language: | English |
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John Wiley and Sons Inc.
2019
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Online Access: | http://hdl.handle.net/10026.1/14718 https://doi.org/10.1029/2018pa003523 |
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ftunivplympearl:oai:pearl.plymouth.ac.uk:10026.1/14718 2024-06-09T07:47:05+00:00 Sea ice control on winter subsurface temperatures of the North Iceland Shelf during the Little Ice Age: A TEX 86 calibration case study Harning, DJ Andrews, JT Belt, ST Cabedo‐Sanz, P Geirsdóttir, Á Dildar, N Miller, GH Sepúlveda, J 2019-06 1006-1021 application/pdf http://hdl.handle.net/10026.1/14718 https://doi.org/10.1029/2018pa003523 en eng John Wiley and Sons Inc. ISSN:2572-4517 ISSN:2572-4525 E-ISSN:2572-4525 2572-4517 2572-4525 2018PA003523 http://hdl.handle.net/10026.1/14718 doi:10.1029/2018pa003523 2020-5-30 Not known 37 Earth Sciences 3709 Physical Geography and Environmental Geoscience 3705 Geology 14 Life Below Water journal-article Article 2019 ftunivplympearl https://doi.org/10.1029/2018pa003523 2024-05-14T23:48:21Z <jats:title>Abstract</jats:title><jats:p>Holocene paleoceanographic reconstructions along the North Iceland Shelf have employed a variety of sea surface temperature and sea ice proxies. However, these surface proxies tend to have a seasonal bias toward spring/summer and thus only provide a discrete snapshot of surface conditions during one season. Furthermore, sea surface temperature proxies can be influenced by additional confounding variables resulting in markedly different Holocene temperature reconstructions. Here, we expand Iceland's marine paleoclimate toolkit with TEX<jats:sub>86</jats:sub><jats:sup>L</jats:sup>: a temperature proxy based on the distribution of archaeal glycerol dibiphytanyl glycerol tetraether (GDGT) lipids. We develop a local Icelandic calibration from 21 surface sediment samples covering a wide environmental gradient across Iceland's insular shelves. Locally calibrated GDGT results demonstrate that (1) TEX<jats:sub>86</jats:sub><jats:sup>L</jats:sup> reflects winter subsurface (0–200 m) temperatures on the North Iceland Shelf and (2) our calibration produces more realistic temperature estimates with substantially lower uncertainty (S.E. ±4 °C) over global calibrations. We then apply this new calibration to a high‐resolution marine sediment core (last millennium) collected from the central NIS with age control constrained by <jats:sup>14</jats:sup>C‐dated mollusks. To test the veracity of the GDGT subsurface temperatures, we analyze quartz and calcite wt% and a series of highly branched isoprenoid alkenes, including the sea ice biomarker IP<jats:sub>25</jats:sub>, from the same core. The sediment records demonstrate that the development of thick sea ice during the Little Ice Age warmed the subsurface due to winter insulation. Importantly, this observation reflects a seasonal component of the sea ice/ocean feedback to be considered for the nonlinear cooling of the Little Ice Age in and around ... Article in Journal/Newspaper Iceland Sea ice PEARL (Plymouth Electronic Archiv & ResearchLibrary, Plymouth University) Paleoceanography and Paleoclimatology 34 6 1006 1021 |
institution |
Open Polar |
collection |
PEARL (Plymouth Electronic Archiv & ResearchLibrary, Plymouth University) |
op_collection_id |
ftunivplympearl |
language |
English |
topic |
37 Earth Sciences 3709 Physical Geography and Environmental Geoscience 3705 Geology 14 Life Below Water |
spellingShingle |
37 Earth Sciences 3709 Physical Geography and Environmental Geoscience 3705 Geology 14 Life Below Water Harning, DJ Andrews, JT Belt, ST Cabedo‐Sanz, P Geirsdóttir, Á Dildar, N Miller, GH Sepúlveda, J Sea ice control on winter subsurface temperatures of the North Iceland Shelf during the Little Ice Age: A TEX 86 calibration case study |
topic_facet |
37 Earth Sciences 3709 Physical Geography and Environmental Geoscience 3705 Geology 14 Life Below Water |
description |
<jats:title>Abstract</jats:title><jats:p>Holocene paleoceanographic reconstructions along the North Iceland Shelf have employed a variety of sea surface temperature and sea ice proxies. However, these surface proxies tend to have a seasonal bias toward spring/summer and thus only provide a discrete snapshot of surface conditions during one season. Furthermore, sea surface temperature proxies can be influenced by additional confounding variables resulting in markedly different Holocene temperature reconstructions. Here, we expand Iceland's marine paleoclimate toolkit with TEX<jats:sub>86</jats:sub><jats:sup>L</jats:sup>: a temperature proxy based on the distribution of archaeal glycerol dibiphytanyl glycerol tetraether (GDGT) lipids. We develop a local Icelandic calibration from 21 surface sediment samples covering a wide environmental gradient across Iceland's insular shelves. Locally calibrated GDGT results demonstrate that (1) TEX<jats:sub>86</jats:sub><jats:sup>L</jats:sup> reflects winter subsurface (0–200 m) temperatures on the North Iceland Shelf and (2) our calibration produces more realistic temperature estimates with substantially lower uncertainty (S.E. ±4 °C) over global calibrations. We then apply this new calibration to a high‐resolution marine sediment core (last millennium) collected from the central NIS with age control constrained by <jats:sup>14</jats:sup>C‐dated mollusks. To test the veracity of the GDGT subsurface temperatures, we analyze quartz and calcite wt% and a series of highly branched isoprenoid alkenes, including the sea ice biomarker IP<jats:sub>25</jats:sub>, from the same core. The sediment records demonstrate that the development of thick sea ice during the Little Ice Age warmed the subsurface due to winter insulation. Importantly, this observation reflects a seasonal component of the sea ice/ocean feedback to be considered for the nonlinear cooling of the Little Ice Age in and around ... |
format |
Article in Journal/Newspaper |
author |
Harning, DJ Andrews, JT Belt, ST Cabedo‐Sanz, P Geirsdóttir, Á Dildar, N Miller, GH Sepúlveda, J |
author_facet |
Harning, DJ Andrews, JT Belt, ST Cabedo‐Sanz, P Geirsdóttir, Á Dildar, N Miller, GH Sepúlveda, J |
author_sort |
Harning, DJ |
title |
Sea ice control on winter subsurface temperatures of the North Iceland Shelf during the Little Ice Age: A TEX 86 calibration case study |
title_short |
Sea ice control on winter subsurface temperatures of the North Iceland Shelf during the Little Ice Age: A TEX 86 calibration case study |
title_full |
Sea ice control on winter subsurface temperatures of the North Iceland Shelf during the Little Ice Age: A TEX 86 calibration case study |
title_fullStr |
Sea ice control on winter subsurface temperatures of the North Iceland Shelf during the Little Ice Age: A TEX 86 calibration case study |
title_full_unstemmed |
Sea ice control on winter subsurface temperatures of the North Iceland Shelf during the Little Ice Age: A TEX 86 calibration case study |
title_sort |
sea ice control on winter subsurface temperatures of the north iceland shelf during the little ice age: a tex 86 calibration case study |
publisher |
John Wiley and Sons Inc. |
publishDate |
2019 |
url |
http://hdl.handle.net/10026.1/14718 https://doi.org/10.1029/2018pa003523 |
genre |
Iceland Sea ice |
genre_facet |
Iceland Sea ice |
op_relation |
ISSN:2572-4517 ISSN:2572-4525 E-ISSN:2572-4525 2572-4517 2572-4525 2018PA003523 http://hdl.handle.net/10026.1/14718 doi:10.1029/2018pa003523 |
op_rights |
2020-5-30 Not known |
op_doi |
https://doi.org/10.1029/2018pa003523 |
container_title |
Paleoceanography and Paleoclimatology |
container_volume |
34 |
container_issue |
6 |
container_start_page |
1006 |
op_container_end_page |
1021 |
_version_ |
1801377818865565696 |