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Tropical forcing of increased Southern Ocean climate variability revealed by a 140-year subantarctic temperature reconstruction.

Authors :
Turney, Chris S. M.
Fogwill, Christopher J.
Palmer, Jonathan G.
van Sebille, Erik
Thomas, Zoë
McGlone, Matt
Richardson, Sarah
Wilmshurst, Janet M.
Fenwick, Pavla
Zunz, Violette
Goosse, Hugues
Wilson, Kerry-Jayne
Carter, Lionel
Lipson, Mathew
Jones, Richard T.
Harsch, Melanie
Clark, Graeme
Marzinelli, Ezequiel
Rogers, Tracey
Rainsley, Eleanor
Source :
Climate of the Past; 2017, Vol. 13 Issue 3, p231-248, 18p
Publication Year :
2017

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. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
18149324
Volume :
13
Issue :
3
Database :
Complementary Index
Journal :
Climate of the Past
Publication Type :
Academic Journal
Accession number :
122355005
Full Text :
https://doi.org/10.5194/cp-13-231-2017