TY - JOUR
T1 - Tropical forcing of increased Southern Ocean climate variability revealed by a 140-year subantarctic temperature reconstruction
AU - Turney, Chris S.M.
AU - Fogwill, Christopher J.
AU - Palmer, Jonathan G.
AU - Van Sebille, Erik
AU - Thomas, Zoë
AU - McGlone, Matt
AU - Richardson, Sarah
AU - Wilmshurst, Janet M.
AU - Fenwick, Pavla
AU - Zunz, Violette
AU - Goosse, Hugues
AU - Wilson, Kerry Jayne
AU - Carter, Lionel
AU - Lipson, Mathew
AU - Jones, Richard T.
AU - Harsch, Melanie
AU - Clark, Graeme
AU - Marzinelli, Ezequiel
AU - Rogers, Tracey
AU - Rainsley, Eleanor
AU - Ciasto, Laura
AU - Waterman, Stephanie
AU - Thomas, Elizabeth R.
AU - Visbeck, Martin
PY - 2017/3/15
Y1 - 2017/3/15
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=85015309253&partnerID=8YFLogxK
U2 - 10.5194/cp-13-231-2017
DO - 10.5194/cp-13-231-2017
M3 - Article
AN - SCOPUS:85015309253
SN - 1814-9324
VL - 13
SP - 231
EP - 248
JO - Climate of the Past
JF - Climate of the Past
IS - 3
ER -