Back to Search
Start Over
Tropical forcing of increased Southern Ocean climate variability revealed by a 140-year subantarctic temperature reconstruction.
- 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]
- Subjects :
- CLIMATE change
TEMPERATURE
ICE sheets
OCEAN temperature
ROSSBY waves
Subjects
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