Chenillat Fanny auteur aut IRD Illig Serena auteur aut IRD Jouanno Julien auteur aut IRD Awo F. M. auteur aut IRD Alory G. auteur aut IRD Brehmer Patrice auteur aut IRD text journalArticle eng text/pdf born digital access Chlorophyll-a concentration (Chl-a) observed by satellite shows a marked seasonal and interannual variability in the tropical Atlantic. This study analyzes how the remotely sensed surface Chl-a responds to the leading boreal summer climate modes affecting the interannual tropical Atlantic variability over 1998-2018, corresponding to a positive Atlantic Multidecadal Oscillation phase. We show that the Atlantic Zonal Mode (AZM) and the North Tropical Atlantic Mode (NTAM) significantly drive the interannual surface Chl-a variability in the equatorial Atlantic, with different timings and contrasted zonal modulation of the cold tongue. The AZM involves remotely forced wave propagations favoring upwelling in the east and Chl-a modulation in the core of the cold tongue. Instead, the impact of the NTAM is mainly in the west, in response to locally forced pumping that modulates the western extension of the cold tongue. Such conditions can affect the marine food web, inducing significant variations for ecosystem functioning and fisheries. specialized tropical Atlantic equatorial Atlantic cold tongue chlorophyll-a concentration interannual variability climate modes remote sensing ATLANTIQUE ZONE TROPICALE ZONE EQUATORIALE 021 032 126 48 14 e2021GL093769 [10 ] 2021 0094-8276 https://www.documentation.ird.fr/hor/fdi:010083284 10.1029/2021gl093769 0094-8276 [F B010083284] https://www.documentation.ird.fr/hor/fdi:010083284 https://www.documentation.ird.fr/intranet/publi/2021-12/010083284.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2021-12-03 2025-02-24 fdi:010083284 fre