Mean sortable silt values from Holocene and glacial Scotia Sea sediments
The Antarctic Circumpolar Current is key to the mixing and ventilation of the world's oceans. This current flows from west to east between about 45° and 70° S connecting the Atlantic, Pacific and Indian oceans, and is driven by westerly winds and buoyancy forcing. High levels of productivity in...
Main Authors: | , , , , |
---|---|
Format: | Dataset |
Language: | English |
Published: |
PANGAEA
2014
|
Subjects: | |
Online Access: | https://doi.pangaea.de/10.1594/PANGAEA.821238 https://doi.org/10.1594/PANGAEA.821238 |
id |
ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.821238 |
---|---|
record_format |
openpolar |
spelling |
ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.821238 2023-05-15T13:42:11+02:00 Mean sortable silt values from Holocene and glacial Scotia Sea sediments McCave, I Nick Crowhurst, Simon J Kuhn, Gerhard Hillenbrand, Claus-Dieter Meredith, Michael P MEDIAN LATITUDE: -56.900352 * MEDIAN LONGITUDE: -42.919939 * SOUTH-BOUND LATITUDE: -60.306000 * WEST-BOUND LONGITUDE: -48.043333 * NORTH-BOUND LATITUDE: -53.666660 * EAST-BOUND LONGITUDE: -36.651170 * DATE/TIME START: 1992-09-13T18:24:00 * DATE/TIME END: 2005-05-14T05:20:00 2014-10-25 application/zip, 12 datasets https://doi.pangaea.de/10.1594/PANGAEA.821238 https://doi.org/10.1594/PANGAEA.821238 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.821238 https://doi.org/10.1594/PANGAEA.821238 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY Supplement to: McCave, I Nick; Crowhurst, Simon J; Kuhn, Gerhard; Hillenbrand, Claus-Dieter; Meredith, Michael P (2014): Minimal change in Antarctic Circumpolar Current flow speed between the last glacial and Holocene. Nature Geoscience, 7, 113–116, https://doi.org/10.1038/ngeo2037 Dataset 2014 ftpangaea https://doi.org/10.1594/PANGAEA.821238 https://doi.org/10.1038/ngeo2037 2023-01-20T07:33:10Z The Antarctic Circumpolar Current is key to the mixing and ventilation of the world's oceans. This current flows from west to east between about 45° and 70° S connecting the Atlantic, Pacific and Indian oceans, and is driven by westerly winds and buoyancy forcing. High levels of productivity in the current regulate atmospheric CO2 concentrations. Reconstructions of the current during the last glacial period suggest that flow speeds were faster or similar to present, and it is uncertain whether the strength and position of the westerly winds changed. Here we reconstruct Antarctic Circumpolar Current bottom speeds through the constricting Drake Passage and Scotia Sea during the Last Glacial Maximum and Holocene based on the mean grain size of sortable silt from a suite of sediment cores. We find essentially no change in bottom flow speeds through the region, and, given that the momentum imparted by winds, and modulated by sea-ice cover, is balanced by the interaction of these flows with the seabed, this argues against substantial changes in wind stress. However, glacial flow speeds in the sea-ice zone south of 56° S were significantly slower than present, whereas flow in the north was faster, but not significantly so. We suggest that slower flow over the rough topography south of 56° S may have reduced diapycnal mixing in this region during the last glacial period, possibly reducing the diapycnal contribution to the Southern Ocean overturning circulation. Dataset Antarc* Antarctic Drake Passage Scotia Sea Sea ice Southern Ocean PANGAEA - Data Publisher for Earth & Environmental Science Antarctic Southern Ocean The Antarctic Drake Passage Scotia Sea Pacific Indian ENVELOPE(-48.043333,-36.651170,-53.666660,-60.306000) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
description |
The Antarctic Circumpolar Current is key to the mixing and ventilation of the world's oceans. This current flows from west to east between about 45° and 70° S connecting the Atlantic, Pacific and Indian oceans, and is driven by westerly winds and buoyancy forcing. High levels of productivity in the current regulate atmospheric CO2 concentrations. Reconstructions of the current during the last glacial period suggest that flow speeds were faster or similar to present, and it is uncertain whether the strength and position of the westerly winds changed. Here we reconstruct Antarctic Circumpolar Current bottom speeds through the constricting Drake Passage and Scotia Sea during the Last Glacial Maximum and Holocene based on the mean grain size of sortable silt from a suite of sediment cores. We find essentially no change in bottom flow speeds through the region, and, given that the momentum imparted by winds, and modulated by sea-ice cover, is balanced by the interaction of these flows with the seabed, this argues against substantial changes in wind stress. However, glacial flow speeds in the sea-ice zone south of 56° S were significantly slower than present, whereas flow in the north was faster, but not significantly so. We suggest that slower flow over the rough topography south of 56° S may have reduced diapycnal mixing in this region during the last glacial period, possibly reducing the diapycnal contribution to the Southern Ocean overturning circulation. |
format |
Dataset |
author |
McCave, I Nick Crowhurst, Simon J Kuhn, Gerhard Hillenbrand, Claus-Dieter Meredith, Michael P |
spellingShingle |
McCave, I Nick Crowhurst, Simon J Kuhn, Gerhard Hillenbrand, Claus-Dieter Meredith, Michael P Mean sortable silt values from Holocene and glacial Scotia Sea sediments |
author_facet |
McCave, I Nick Crowhurst, Simon J Kuhn, Gerhard Hillenbrand, Claus-Dieter Meredith, Michael P |
author_sort |
McCave, I Nick |
title |
Mean sortable silt values from Holocene and glacial Scotia Sea sediments |
title_short |
Mean sortable silt values from Holocene and glacial Scotia Sea sediments |
title_full |
Mean sortable silt values from Holocene and glacial Scotia Sea sediments |
title_fullStr |
Mean sortable silt values from Holocene and glacial Scotia Sea sediments |
title_full_unstemmed |
Mean sortable silt values from Holocene and glacial Scotia Sea sediments |
title_sort |
mean sortable silt values from holocene and glacial scotia sea sediments |
publisher |
PANGAEA |
publishDate |
2014 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.821238 https://doi.org/10.1594/PANGAEA.821238 |
op_coverage |
MEDIAN LATITUDE: -56.900352 * MEDIAN LONGITUDE: -42.919939 * SOUTH-BOUND LATITUDE: -60.306000 * WEST-BOUND LONGITUDE: -48.043333 * NORTH-BOUND LATITUDE: -53.666660 * EAST-BOUND LONGITUDE: -36.651170 * DATE/TIME START: 1992-09-13T18:24:00 * DATE/TIME END: 2005-05-14T05:20:00 |
long_lat |
ENVELOPE(-48.043333,-36.651170,-53.666660,-60.306000) |
geographic |
Antarctic Southern Ocean The Antarctic Drake Passage Scotia Sea Pacific Indian |
geographic_facet |
Antarctic Southern Ocean The Antarctic Drake Passage Scotia Sea Pacific Indian |
genre |
Antarc* Antarctic Drake Passage Scotia Sea Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Drake Passage Scotia Sea Sea ice Southern Ocean |
op_source |
Supplement to: McCave, I Nick; Crowhurst, Simon J; Kuhn, Gerhard; Hillenbrand, Claus-Dieter; Meredith, Michael P (2014): Minimal change in Antarctic Circumpolar Current flow speed between the last glacial and Holocene. Nature Geoscience, 7, 113–116, https://doi.org/10.1038/ngeo2037 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.821238 https://doi.org/10.1594/PANGAEA.821238 |
op_rights |
CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1594/PANGAEA.821238 https://doi.org/10.1038/ngeo2037 |
_version_ |
1766164556611059712 |