Illig Serena auteur aut IRD Bachelery M. L. auteur aut IRD text journalArticle eng text/pdf reformatted digital access The oceanic connection between the coastal variability along the southwestern African coasts and the linear equatorial dynamics at subseasonal time-scales (<120 days) is examined using a variety of model outputs, ranging from linear to general circulation models. We focus on the equatorially-forced fast and weakly dissipative first-mode coastal trapped waves which are shown to propagate down to the southern tip of Africa. In the eastern equatorial Atlantic, the first-mode equatorial forcing is tangled with the higher-order Kelvin wave modes and is overshadowed by the dominant second baroclinic mode. The latter is slower and peaks 10 days after the concealed first-mode contribution. Within this time frame, the remotely-forced first-mode coastal trapped waves impinge on the variability of the Benguela upwelling ecosystem, almost in phase with the subseasonal sea level fluctuations in the Gulf of Guinea. Over 1993-2008, the equatorial forcing undergoes a substantial interannual modulation. Periods of energetic first-mode equatorial Kelvin waves coincide with a strong subseasonal coastal wind activity that breaks the stronger equatorial connection. This suggests the existence of a large-scale atmospheric connection between the equatorial wave forcing and the along-shore winds in the Benguela, modulating the maximum latitude at which the equatorial dynamics impacts the local marine resources. specialized ATLANTIQUE 032 9 art. 5306 [10 ] 2019 2045-2322 https://www.documentation.ird.fr/hor/fdi:010075550 10.1038/s41598-019-41847-1 2045-2322 [F B010075550] https://www.documentation.ird.fr/hor/fdi:010075550 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers19-04/010075550.pdf IRD - Base Horizon / Pleins textes 2019-05-13 2025-02-24 fdi:010075550 fre