Evidence for increased expression of the Amundsen Sea Low over the South Atlantic during the late Holocene

The Amundsen Sea Low (ASL) plays a major role in the climate and environment of Antarctica and the Southern Ocean, including surface air temperature and sea ice concentration changes. Unfortunately, a relative dearth of observational data across the Amundsen and Bellingshausen seas prior to the sate...

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Published in:Climate of the Past
Main Authors: Thomas, Zoë A., Jones, Richard T., Fogwill, Chris J., Hatton, Jackie, Williams, Alan N., Hogg, Alan, Mooney, Scott, Jones, Philip, Lister, David, Mayewski, Paul, Turney, Chris S. M.
Format: Text
Language:English
Published: 2018
Subjects:
geo
Online Access:https://doi.org/10.5194/cp-14-1727-2018
https://cp.copernicus.org/articles/14/1727/2018/
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spelling fttriple:oai:gotriple.eu:10670/1.xh83mf 2023-05-15T13:23:57+02:00 Evidence for increased expression of the Amundsen Sea Low over the South Atlantic during the late Holocene Thomas, Zoë A. Jones, Richard T. Fogwill, Chris J. Hatton, Jackie Williams, Alan N. Hogg, Alan Mooney, Scott Jones, Philip Lister, David Mayewski, Paul Turney, Chris S. M. 2018-11-28 https://doi.org/10.5194/cp-14-1727-2018 https://cp.copernicus.org/articles/14/1727/2018/ en eng doi:10.5194/cp-14-1727-2018 10670/1.xh83mf https://cp.copernicus.org/articles/14/1727/2018/ undefined Geographica Helvetica - geography eISSN: 1814-9332 geo envir Text https://vocabularies.coar-repositories.org/resource_types/c_18cf/ 2018 fttriple https://doi.org/10.5194/cp-14-1727-2018 2023-01-22T18:13:39Z The Amundsen Sea Low (ASL) plays a major role in the climate and environment of Antarctica and the Southern Ocean, including surface air temperature and sea ice concentration changes. Unfortunately, a relative dearth of observational data across the Amundsen and Bellingshausen seas prior to the satellite era (post-1979) limits our understanding of the past behaviour and impact of the ASL. The limited proxy evidence for changes in the ASL are primarily restricted to the Antarctic where ice core evidence suggests a deepening of the atmospheric pressure system during the late Holocene. However, no data have previously been reported from the northern side of the ASL. Here we report a high-resolution, multi-proxy study of a 5000-year-long peat record from the Falkland Islands, a location sensitive to contemporary ASL dynamics which modulates northerly and westerly airflow across the southwestern South Atlantic sector of the Southern Ocean. In combination with climate reanalysis, we find a marked period of wetter, colder conditions most likely the result of enhanced southerly airflow between 5000 and 2500 years ago, suggesting limited ASL influence over the region. After 2500 years ago, drier and warmer conditions were established, implying more westerly airflow and the increased projection of the ASL onto the South Atlantic. The possible role of the equatorial Pacific via atmospheric teleconnections in driving this change is discussed. Our results are in agreement with Antarctic ice core records and fjord sediments from the southern South American coast, and suggest that the Falkland Islands provide a valuable location for reconstructing high southern latitude atmospheric circulation changes on multi-decadal to millennial timescales. Text Amundsen Sea Antarc* Antarctic Antarctica ice core Sea ice Southern Ocean Unknown Amundsen Sea Antarctic Pacific Southern Ocean The Antarctic Climate of the Past 14 11 1727 1738
institution Open Polar
collection Unknown
op_collection_id fttriple
language English
topic geo
envir
spellingShingle geo
envir
Thomas, Zoë A.
Jones, Richard T.
Fogwill, Chris J.
Hatton, Jackie
Williams, Alan N.
Hogg, Alan
Mooney, Scott
Jones, Philip
Lister, David
Mayewski, Paul
Turney, Chris S. M.
Evidence for increased expression of the Amundsen Sea Low over the South Atlantic during the late Holocene
topic_facet geo
envir
description The Amundsen Sea Low (ASL) plays a major role in the climate and environment of Antarctica and the Southern Ocean, including surface air temperature and sea ice concentration changes. Unfortunately, a relative dearth of observational data across the Amundsen and Bellingshausen seas prior to the satellite era (post-1979) limits our understanding of the past behaviour and impact of the ASL. The limited proxy evidence for changes in the ASL are primarily restricted to the Antarctic where ice core evidence suggests a deepening of the atmospheric pressure system during the late Holocene. However, no data have previously been reported from the northern side of the ASL. Here we report a high-resolution, multi-proxy study of a 5000-year-long peat record from the Falkland Islands, a location sensitive to contemporary ASL dynamics which modulates northerly and westerly airflow across the southwestern South Atlantic sector of the Southern Ocean. In combination with climate reanalysis, we find a marked period of wetter, colder conditions most likely the result of enhanced southerly airflow between 5000 and 2500 years ago, suggesting limited ASL influence over the region. After 2500 years ago, drier and warmer conditions were established, implying more westerly airflow and the increased projection of the ASL onto the South Atlantic. The possible role of the equatorial Pacific via atmospheric teleconnections in driving this change is discussed. Our results are in agreement with Antarctic ice core records and fjord sediments from the southern South American coast, and suggest that the Falkland Islands provide a valuable location for reconstructing high southern latitude atmospheric circulation changes on multi-decadal to millennial timescales.
format Text
author Thomas, Zoë A.
Jones, Richard T.
Fogwill, Chris J.
Hatton, Jackie
Williams, Alan N.
Hogg, Alan
Mooney, Scott
Jones, Philip
Lister, David
Mayewski, Paul
Turney, Chris S. M.
author_facet Thomas, Zoë A.
Jones, Richard T.
Fogwill, Chris J.
Hatton, Jackie
Williams, Alan N.
Hogg, Alan
Mooney, Scott
Jones, Philip
Lister, David
Mayewski, Paul
Turney, Chris S. M.
author_sort Thomas, Zoë A.
title Evidence for increased expression of the Amundsen Sea Low over the South Atlantic during the late Holocene
title_short Evidence for increased expression of the Amundsen Sea Low over the South Atlantic during the late Holocene
title_full Evidence for increased expression of the Amundsen Sea Low over the South Atlantic during the late Holocene
title_fullStr Evidence for increased expression of the Amundsen Sea Low over the South Atlantic during the late Holocene
title_full_unstemmed Evidence for increased expression of the Amundsen Sea Low over the South Atlantic during the late Holocene
title_sort evidence for increased expression of the amundsen sea low over the south atlantic during the late holocene
publishDate 2018
url https://doi.org/10.5194/cp-14-1727-2018
https://cp.copernicus.org/articles/14/1727/2018/
geographic Amundsen Sea
Antarctic
Pacific
Southern Ocean
The Antarctic
geographic_facet Amundsen Sea
Antarctic
Pacific
Southern Ocean
The Antarctic
genre Amundsen Sea
Antarc*
Antarctic
Antarctica
ice core
Sea ice
Southern Ocean
genre_facet Amundsen Sea
Antarc*
Antarctic
Antarctica
ice core
Sea ice
Southern Ocean
op_source Geographica Helvetica - geography
eISSN: 1814-9332
op_relation doi:10.5194/cp-14-1727-2018
10670/1.xh83mf
https://cp.copernicus.org/articles/14/1727/2018/
op_rights undefined
op_doi https://doi.org/10.5194/cp-14-1727-2018
container_title Climate of the Past
container_volume 14
container_issue 11
container_start_page 1727
op_container_end_page 1738
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