Assessing recent trends in high-latitude Southern Hemisphere surface climate

Julie M. Jones (1) , Sarah T. Gille (2) , Hugues Goosse (3) , Nerilie J. Abram (4) , Pablo Canziani , Dan Charman , Kyle Clem , Xavier Crosta (5) , Casimir de Lavergne (6) , Ian Eisenman (2) , Matthew H. England (7) , Ryan Fogt , Leela Frankcombe , Gareth Marshall , Valérie Masson-Delmotte (8, 9) , Adele Morrison , Anaïs Orsi (8, 9) , Marilyn Raphael , James Renwick , David Schneider (10) , Graham Simpkins , Eric J. Steig , Barbara Stenni (11) , Didier Swingedouw (5) , Tessa Vance

1 Department of Geography [Sheffield]
2 SIO - UC San Diego - Scripps Institution of Oceanography
3 UCL-ASTR - Institut d'Astronomie et de Géophysique Georges Lemaître
4 ANU - Australian National University
5 EPOC - Environnements et Paléoenvironnements OCéaniques
6 NEMO R&D - Nucleus for European Modeling of the Ocean
7 School of Computing, Electronics and Mathematics [Coventry]
8 LSCE - Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette]
9 GLACCIOS - Glaces et Continents, Climats et Isotopes Stables
10 NCAR - National Center for Atmospheric Research [Boulder]
11 University of Ca’ Foscari [Venice, Italy]

Understanding the causes of recent climatic trends and variability in the high-latitude Southern Hemisphere is hampered by a short instrumental record. Here, we analyse recent atmosphere, surface ocean and sea-ice observations in this region and assess their trends in the context of palaeoclimate records and climate model simulations. Over the 36-year satellite era, significant linear trends in annual mean sea-ice extent, surface temperature and sea-level pressure are superimposed on large interannual to decadal variability. Most observed trends, however, are not unusual when compared with Antarctic palaeoclimate records of the past two centuries. With the exception of the positive trend in the Southern Annular Mode, climate model simulations that include anthropogenic forcing are not compatible with the observed trends. This suggests that natural variability overwhelms the forced response in the observations, but the models may not fully represent this natural variability or may overestimate the magnitude of the forced response.

Domaines: Océan, Atmosphère; Océanographie; Climatologie

Julie M. Jones, Sarah T. Gille, Hugues Goosse, Nerilie J. Abram, Pablo Canziani, et al.. Assessing recent trends in high-latitude Southern Hemisphere surface climate. Nature Climate Change, 2016, 6 (10), pp.917-926. ⟨10.1038/NCLIMATE3103⟩. ⟨hal-02105548⟩