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

Tools

Thomas, Zoë A., Jones, Richard T., Fogwill, Chris J., Hatton, Jackie, Williams, Alan N., Hogg, Alan, Mooney, Scott, Jones, Philip ORCID: https://orcid.org/0000-0001-5032-5493, Lister, David, Mayewski, Paul and Turney, Chris S. M. (2018) Evidence for increased expression of the Amundsen Sea Low over the South Atlantic during the late Holocene. Climate of the Past, 14 (11). pp. 1727-1738. ISSN 1814-9324

[thumbnail of Published manuscript]
Preview
 PDF (Published manuscript) - Published Version
Available under License Creative Commons Attribution.
Download (11MB) | Preview

Abstract

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.

Item Type: Article
Uncontrolled Keywords: sdg 13 - climate action ,/dk/atira/pure/sustainabledevelopmentgoals/climate_action
Faculty \ School: Faculty of Science > School of Environmental Sciences
UEA Research Groups: Faculty of Science > Research Groups > Climatic Research Unit
Faculty of Science > Research Groups > Centre for Ocean and Atmospheric Sciences
Related URLs:
Depositing User: LivePure Connector
Date Deposited: 03 Dec 2018 12:30
Last Modified: 14 Jun 2023 13:35
URI: https://ueaeprints.uea.ac.uk/id/eprint/69137
DOI: 10.5194/cp-14-1727-2018

Downloads

Downloads per month over past year

Actions (login required)

View Item View Item