Tropical forcing of increased Southern Ocean climate variability revealed by a 140-year subantarctic temperature reconstruction
Year: 2017
Type: article
Abstract: . Occupying about 14 % of the world's surface, the Southern Ocean plays a fundamental role in ocean and atmosphere circulation, carbon cycling and Antarctic ice-sheet dynamics. Unfortunately, high interannual variability and a dearth of instrumental observations before the 1950s limits our understanding of how marine–atmosphere–ice domains interact on multi-decadal timescales and the impact of anthropogenic forcing. Here we integrate climate-sensitive tree growth with ocean and atmospheric observations on southwest Pacific subantarctic islands that lie at the boundary of polar and subtropical climates (52–54° S). Our annually resolved temperature reconstruction captures regional change since the 1870s and demonstrates a significant increase in variability from the 1940s, a phenomenon predating the observational record. Climate reanalysis and modelling show a parallel change in tropical Pacific sea surface temperatures that generate an atmospheric Rossby wave train which propagates across a large part of the Southern Hemisphere during the austral spring and summer. Our results suggest that modern observed high interannual variability was established across the mid-twentieth century, and that the influence of contemporary equatorial Pacific temperatures may now be a permanent feature across the mid- to high latitudes.
Source: Climate of the past
Authors: Chris S. M. Turney, Christopher J. Fogwill, Jonathan G. Palmer, Erik van Sebille, Zoë Thomas, Matt McGlone, Sarah Richardson, Janet M. Wilmshurst, Pavla Fenwick, Violette Zunz, Hugues Goosse, Kerry-Jayne Wilson, Lionel Carter, Mathew Lipson, Richard T. Jones, Melanie Harsch, Graeme Clark, Ezequiel Marzinelli, Tracey Rogers, Eleanor Rainsley, Laura Ciasto, Stephanie Waterman, Elizabeth R. Thomas, Martin Visbeck
Institutions: UNSW Sydney, Climate Change Research Centre, ARC Centre of Excellence for Climate System Science, Imperial College London, Manaaki Whenua – Landcare Research, University of Auckland, Vrije Universiteit Brussel, UCLouvain, Victoria University of Wellington, University of Exeter, University of Washington, Sydney Institute of Marine Science, University of Wollongong, Bjerknes Centre for Climate Research, University of Bergen, University of British Columbia, British Antarctic Survey, Christian-Albrechts-Universität zu Kiel, GEOMAR Helmholtz Centre for Ocean Research Kiel
Language: English
Subfield: Global and Planetary Change
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,725
Awards: G4098071017, Understanding the drivers and impacts of long-term Antarctic ice sheet change, Tipping points in Records of Extreme Events in Australasia: Using the Past to Understand and Plan for Abrupt Future Climate Change, Reconstructing wind strength and atmospheric circulation in West Antarctica over the past 300 years, Reconstructing changes in atmospheric circulation over the mid-latitudes of the Southern Hemisphere during the past 3000 years, Inter-ocean exchange around Australia and its relation to regional and global climate
OpenAlex ID: W2551781256