Recent Climate Variability around the Kerguelen Islands (Southern Ocean) Seen through Weather Regimes

Type Article
Date 2021-05
Language English
Author(s) Pohl BenjaminORCID1, Saucede Thomas1, Favier VincentORCID2, Pergaud Julien1, Verfaillie Deborah3, Feral Jean-Pierre4, Krasniqi Ylber1, Richard Yves1
Affiliation(s) 1 : Biogéosciences, UMR6282 CNRS/Université de Bourgogne Franche-Comté, Dijon, France
2 : Université Grenoble Alpes/CNRS/IRD/G-INP, IGE, Grenoble, France
3 : Georges Lema^ıtre Centre for Earth and Climate Research, Earth and Life Institute, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
4 : Aix Marseille Université/CNRS/IRD/Avignon Université, IMBE-UMR7263, Station Marine d’Endoume, Marseille, France
Source Journal Of Applied Meteorology And Climatology (1558-8424) (Amer Meteorological Soc), 2021-05 , Vol. 60 , N. 5 , P. 711-731
DOI 10.1175/JAMC-D-20-0255.1
WOS© Times Cited 8
Keyword(s) Southern Ocean, Antarctic Oscillation, Climate variability, Interannual variability, Southern Oscillation
Abstract

Daily weather regimes are defined around the Kerguelen Islands (Southern Ocean) on the basis of daily 500-hPa geopotential height anomalies derived from the ERA5 ensemble reanalysis over the period 1979-2018. Ten regimes are retained as significant. Their occurrences are highly consistent across reanalysis ensemble members. Regimes show weak seasonality and nonsignificant long-term trends in their occurrences. Their sequences are usually short (1-3 days), with extreme persistence values above 10 days. Seasonal regime frequency is mostly driven by the phase of the southern annular mode over Antarctica, midlatitude dynamics over the Southern Ocean such as the Pacific-South American mode, and, to a lesser extent, tropical variability, with significant but weaker relationships with El Nino-Southern Oscillation. At the local scale over the Kerguelen Islands, regimes have a strong influence on measured atmospheric and oceanic variables, including minimum and maximum air temperature, mostly driven by horizontal advections, seawater temperature recorded 5 m below the surface, wind speed, and sea level pressure. Relationships are weaker for precipitation amounts. Regimes also modify regional contrasts between observational sites in Kerguelen, highlighting strong exposure contrasts. The regimes allow us to improve our understanding of weather and climate variability and interactions in this region; they will be used in future work to assess past and projected long-term circulation changes in the southern midlatitudes.

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How to cite 

Pohl Benjamin, Saucede Thomas, Favier Vincent, Pergaud Julien, Verfaillie Deborah, Feral Jean-Pierre, Krasniqi Ylber, Richard Yves (2021). Recent Climate Variability around the Kerguelen Islands (Southern Ocean) Seen through Weather Regimes. Journal Of Applied Meteorology And Climatology, 60(5), 711-731. Publisher's official version : https://doi.org/10.1175/JAMC-D-20-0255.1 , Open Access version : https://archimer.ifremer.fr/doc/00838/94945/