Temperature changes in the mid- and high-latitudes of the Southern Hemisphere.

• Published in: International Journal of Climatology
• Main Authors: Richard, Yves, Rouault, Mathieu, Pohl, Benjamin, Crétat, Julien, Duclot, I., Taboulot, S., Reason, C.J.C., Macron, Clémence, Buiron, D.
• Other Authors: Biogéosciences UMR 6282 (BGS), Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS), Department of Oceanography Cape Town, University of Cape Town, Nansen-Tutu Centre for Marine Environmental Research, Météo-France, Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Funding from CNRS, NRF, Nansen-Tutu Centre for Marine Environmental Research and ACCESS.
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2013
• Subjects: climate change; temperature; Southern Hemisphere; regionalization; Sub-Antarctic islands; Southern Annular Mode; sea surface temperature; [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; [SDE.MCG]Environmental Sciences/Global Changes; Antarc*; Antarctic; Antarctic Peninsula; Antarctica; East Antarctica
• Online Access: https://hal.science/hal-00839624; https://doi.org/10.1002/joc.3563

16 pages International audience A Hierarchical Ascending Classification is used to regionalize monthly temperature anomalies measured at 24 weather stations in Antarctica and the Sub-Antarctic and mid-latitude southern islands from 1973 to 2002. Three principal regions are identified that are geographically coherent: Eastern Antarctica, the Antarctic Peninsula and the Sub- Antarctic and mid-latitude islands. Within each region, consistent trends are observed: namely, stationary temperatures in 'East-Antarctica'; a robust warming in the 'Sub-Antarctic and mid-latitude islands', most pronounced in austral summer (nearly 0.5 °C per decade); and a strong but more recent warming in the 'Antarctic Peninsula'. Austral summer temperature anomalies are related to (1) the Southern Annular Mode (SAM) indexes computed using two reanalysis products (20th Century Reanalyses and ERA40) over two periods (1958-2002 and 1973-2002), (2) the seasonal frequencies of four recurrent daily weather regimes identified with a k-means algorithm applied on the 500hPa geopotential height (DJF 1958-2002) and (3) HadSST2 sea surface temperature (SST) anomalies (DJF 1958-2002). East-Antarctica interannual temperature anomalies are associated with the SAM variability. In the Antarctic Peninsula, only the long-term trend is common with the SAM. The SAM does impact significantly the temperature anomalies of the Sub-Antarctic and midlatitude islands. Trend and interannual variability of the islands' temperatures are associated with the nearby SST. For the Indian Ocean stations, warming in the Agulhas Current system could also have led to these changes.