Variability of Sea Ice Cover in the Chukchi Sea (Western Arctic Ocean) During the Holocene
Dinocysts from cores collected in the Chukchi Sea from the shelf edge to the lower slope were used to reconstruct changes in sea surface conditions and sea ice cover using modern analogue techniques. Holocene sequences have been recovered in a down-slope core (B15: 2135 m, 75°44'N, sedimentatio...
Published in: | Paleoceanography |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
ODU Digital Commons
2005
|
Subjects: | |
Online Access: | https://digitalcommons.odu.edu/oeas_fac_pubs/303 https://doi.org/10.1029/2005pa001157 https://digitalcommons.odu.edu/context/oeas_fac_pubs/article/1314/viewcontent/variability_ice_2005.pdf |
id |
ftolddominionuni:oai:digitalcommons.odu.edu:oeas_fac_pubs-1314 |
---|---|
record_format |
openpolar |
spelling |
ftolddominionuni:oai:digitalcommons.odu.edu:oeas_fac_pubs-1314 2023-06-11T04:09:22+02:00 Variability of Sea Ice Cover in the Chukchi Sea (Western Arctic Ocean) During the Holocene Vernal, Anne de Hillaire-Marcel, Claude Darby, Dennis A 2005-01-01T08:00:00Z application/pdf https://digitalcommons.odu.edu/oeas_fac_pubs/303 https://doi.org/10.1029/2005pa001157 https://digitalcommons.odu.edu/context/oeas_fac_pubs/article/1314/viewcontent/variability_ice_2005.pdf unknown ODU Digital Commons https://digitalcommons.odu.edu/oeas_fac_pubs/303 doi:10.1029/2005pa001157 https://digitalcommons.odu.edu/context/oeas_fac_pubs/article/1314/viewcontent/variability_ice_2005.pdf OES Faculty Publications Sea ice Variability Chukchi Sea Holocene Shelf edge Climate change Geology Oceanography Paleontology article 2005 ftolddominionuni https://doi.org/10.1029/2005pa001157 2023-05-08T18:00:18Z Dinocysts from cores collected in the Chukchi Sea from the shelf edge to the lower slope were used to reconstruct changes in sea surface conditions and sea ice cover using modern analogue techniques. Holocene sequences have been recovered in a down-slope core (B15: 2135 m, 75°44'N, sedimentation rate of ~1cm kyr-1) and in a shelf core (P1: 201 m, 73°41'N, sedimentation rate of ~22 cm kyr-1). The shelf record spanning about 8000 years suggests high-frequency centennial oscillations of sea surface conditions and a significant reduction of the sea ice at circa 6000 and 2500 calendar (cal) years B.P. The condensed offshore record (B15) reveals an early postglacial optimum with minimum sea ice cover prior to 12,000 cal years B.P., which corresponds to a terrestrial climate optimum in Bering Sea area. Dinocyst data indicate extensive sea ice cover (>10 months yr-1) from 12,000 to 6000 cal years B.P. followed by a general trend of decreasing sea ice and increasing sea surface salinity conditions, superimposed on large-amplitude millennial-scale oscillations. In contrast, δ18O data in mesopelagic foraminifers (Neogloboquadrina pachyderma) and benthic foraminifers (Cibicides wuellerstorfi) reveal maximum subsurface temperature and thus maximum inflow of the North Atlantic water around 8000 cal years B.P., followed by a trend toward cooling of the subsurface to bottom water masses. Sea-surface to subsurface conditions estimated from dinocysts and δ18O data in foraminifers thus suggest a decoupling between the surface water layer and the intermediate North Atlantic water mass with the existence of a sharp halocline and a reverse thermocline, especially before 6000 years B.P. The overall data and sea ice reconstructions from core B15 are consistent with strong sea ice convergence in the western Arctic during the early Holocene as suggested on the basis of climate model experiments including sea ice dynamics, matching a higher inflow rate of North Atlantic Water. Article in Journal/Newspaper Arctic Arctic Ocean Bering Sea Chukchi Chukchi Sea Climate change Neogloboquadrina pachyderma North Atlantic Sea ice Old Dominion University: ODU Digital Commons Arctic Arctic Ocean Bering Sea Chukchi Sea Paleoceanography 20 4 n/a n/a |
institution |
Open Polar |
collection |
Old Dominion University: ODU Digital Commons |
op_collection_id |
ftolddominionuni |
language |
unknown |
topic |
Sea ice Variability Chukchi Sea Holocene Shelf edge Climate change Geology Oceanography Paleontology |
spellingShingle |
Sea ice Variability Chukchi Sea Holocene Shelf edge Climate change Geology Oceanography Paleontology Vernal, Anne de Hillaire-Marcel, Claude Darby, Dennis A Variability of Sea Ice Cover in the Chukchi Sea (Western Arctic Ocean) During the Holocene |
topic_facet |
Sea ice Variability Chukchi Sea Holocene Shelf edge Climate change Geology Oceanography Paleontology |
description |
Dinocysts from cores collected in the Chukchi Sea from the shelf edge to the lower slope were used to reconstruct changes in sea surface conditions and sea ice cover using modern analogue techniques. Holocene sequences have been recovered in a down-slope core (B15: 2135 m, 75°44'N, sedimentation rate of ~1cm kyr-1) and in a shelf core (P1: 201 m, 73°41'N, sedimentation rate of ~22 cm kyr-1). The shelf record spanning about 8000 years suggests high-frequency centennial oscillations of sea surface conditions and a significant reduction of the sea ice at circa 6000 and 2500 calendar (cal) years B.P. The condensed offshore record (B15) reveals an early postglacial optimum with minimum sea ice cover prior to 12,000 cal years B.P., which corresponds to a terrestrial climate optimum in Bering Sea area. Dinocyst data indicate extensive sea ice cover (>10 months yr-1) from 12,000 to 6000 cal years B.P. followed by a general trend of decreasing sea ice and increasing sea surface salinity conditions, superimposed on large-amplitude millennial-scale oscillations. In contrast, δ18O data in mesopelagic foraminifers (Neogloboquadrina pachyderma) and benthic foraminifers (Cibicides wuellerstorfi) reveal maximum subsurface temperature and thus maximum inflow of the North Atlantic water around 8000 cal years B.P., followed by a trend toward cooling of the subsurface to bottom water masses. Sea-surface to subsurface conditions estimated from dinocysts and δ18O data in foraminifers thus suggest a decoupling between the surface water layer and the intermediate North Atlantic water mass with the existence of a sharp halocline and a reverse thermocline, especially before 6000 years B.P. The overall data and sea ice reconstructions from core B15 are consistent with strong sea ice convergence in the western Arctic during the early Holocene as suggested on the basis of climate model experiments including sea ice dynamics, matching a higher inflow rate of North Atlantic Water. |
format |
Article in Journal/Newspaper |
author |
Vernal, Anne de Hillaire-Marcel, Claude Darby, Dennis A |
author_facet |
Vernal, Anne de Hillaire-Marcel, Claude Darby, Dennis A |
author_sort |
Vernal, Anne de |
title |
Variability of Sea Ice Cover in the Chukchi Sea (Western Arctic Ocean) During the Holocene |
title_short |
Variability of Sea Ice Cover in the Chukchi Sea (Western Arctic Ocean) During the Holocene |
title_full |
Variability of Sea Ice Cover in the Chukchi Sea (Western Arctic Ocean) During the Holocene |
title_fullStr |
Variability of Sea Ice Cover in the Chukchi Sea (Western Arctic Ocean) During the Holocene |
title_full_unstemmed |
Variability of Sea Ice Cover in the Chukchi Sea (Western Arctic Ocean) During the Holocene |
title_sort |
variability of sea ice cover in the chukchi sea (western arctic ocean) during the holocene |
publisher |
ODU Digital Commons |
publishDate |
2005 |
url |
https://digitalcommons.odu.edu/oeas_fac_pubs/303 https://doi.org/10.1029/2005pa001157 https://digitalcommons.odu.edu/context/oeas_fac_pubs/article/1314/viewcontent/variability_ice_2005.pdf |
geographic |
Arctic Arctic Ocean Bering Sea Chukchi Sea |
geographic_facet |
Arctic Arctic Ocean Bering Sea Chukchi Sea |
genre |
Arctic Arctic Ocean Bering Sea Chukchi Chukchi Sea Climate change Neogloboquadrina pachyderma North Atlantic Sea ice |
genre_facet |
Arctic Arctic Ocean Bering Sea Chukchi Chukchi Sea Climate change Neogloboquadrina pachyderma North Atlantic Sea ice |
op_source |
OES Faculty Publications |
op_relation |
https://digitalcommons.odu.edu/oeas_fac_pubs/303 doi:10.1029/2005pa001157 https://digitalcommons.odu.edu/context/oeas_fac_pubs/article/1314/viewcontent/variability_ice_2005.pdf |
op_doi |
https://doi.org/10.1029/2005pa001157 |
container_title |
Paleoceanography |
container_volume |
20 |
container_issue |
4 |
container_start_page |
n/a |
op_container_end_page |
n/a |
_version_ |
1768383176476983296 |