Poppeschi C. auteur aut IRD Charria G. auteur aut IRD Goberville E. auteur aut IRD Rimmelin-Maury P. auteur aut IRD Barrier Nicolas auteur aut IRD Petton S. auteur aut IRD Unterberger M. auteur aut IRD Grossteffan E. auteur aut IRD Repecaud M. auteur aut IRD Quemener L. auteur aut IRD Theetten S. auteur aut IRD Le Roux J. F. auteur aut IRD Treguer P. auteur aut IRD text journalArticle eng text/pdf reformatted digital access Extreme weather events affect coastal marine ecosystems. The increase in intensity and occurrence of such events drive modifications in coastal hydrology and hydrodynamics. Here, focusing on the winter period (from December to March), we investigated multidecade (2000-2018) changes in the hydrological properties of the Bay of Brest (French Atlantic coast) as an example of the response of a semi-enclosed bay to extreme weather episodes and large-scale atmospheric circulation patterns. The relationships between extreme weather events and severe low salinity conditions (as a proxy for changes in water density) were investigated using high-frequency in situ observations and high-resolution numerical simulations. The identification of intense episodes was based on the timing, duration, and annual occurrence of extreme events. By examining the interannual variability of extreme low salinity events, we detect a patent influence of local and regional weather conditions on atmospheric and oceanic circulation patterns, precipitation, and river runoff. We revealed that low salinity events in Brittany were controlled by large-scale forcings: they prevailed during the positive phase of the North Atlantic Oscillation and periods of low occurrences of the Atlantic Ridge weather regime. The increase in severe storms observed in western France since 2010 has led to a doubling of the occurrence and duration of extreme low salinity events in Brittany. specialized Bay of Brest salinity river plume atmospheric weather regimes extreme events FRANCE ATLANTIQUE BREST BAIE 036 021 8 705403 [14 p.] 2021 https://www.documentation.ird.fr/hor/fdi:010082613 10.3389/fmars.2021.705403 [F B010082613] https://www.documentation.ird.fr/hor/fdi:010082613 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2021-09/010082613.pdf IRD - Base Horizon / Pleins textes 2021-09-17 2025-02-24 fdi:010082613 fre