Rodriguez-Burgos A. M. auteur aut IRD Briceño-Zuluaga F. J. auteur aut IRD Evangelista H. auteur aut IRD Flores-Aqueveque V. auteur aut IRD Nogueira J. auteur aut IRD Castillo A. auteur aut IRD Quiroga-Camargo W. E. auteur aut IRD Mendez-Millan Mercedes auteur aut IRD Sifeddine Abdelfettah auteur aut IRD text journalArticle eng text/pdf born digital access The Caribbean upwelling system enhances the productivity of North Colombian coastal waters, supporting the trophic network and regional biodiversity. Despite knowledge of its mechanisms and drivers, Caribbean upwelling remains understudied, and its response to climate change is uncertain. This study presents the first paleoclimatic reconstruction of upwelling in La Guajira, Colombia (a climate-sensitive region) by analyzing environmental indicators from a marine sediment core (GUACO-4) collected off Bahia Hondita. Organic matter proxies (total organic carbon, total nitrogen, delta 13C, delta 15N) were used to trace its origin and nutrient cycling, while mineral and metal compositions informed ocean-land interactions and thermal changes. Five climatic phases were identified: the Roman Warm Period, the Dark Ages Cold Period, the Medieval Climate Anomaly, the Little Ice Age, and the Current Warm Period. delta 13C values (-21.5 to -19.7 %o) and C/N ratios (4.47-5.90) indicate a mainly marine origin of organic matter, and delta 15N values (4.24 to 5.58 %o) suggest active denitrification. Warm periods aligned with El Nino-like conditions and stronger coupling between the North Atlantic Subtropical High and the Intertropical Convergence Zone, intensifying the Caribbean Low-Level Jet and enhancing productivity. In contrast, during the Little Ice Age, La Nina-like conditions and system decoupling weakened the Jet. Today, increased variability adds uncertainty to future upwelling dynamics. Climate-driven changes in wind patterns could either strengthen or weaken upwelling. This unpredictability could impact marine productivity, with potential consequences for fisheries and local communities that rely on these ecosystems. specialized Late Holocene Southern Caribbean Marine productivity Climate-ocean coupling Sediment geochemistry Climate variability COLOMBIE, LA GUAJIRA ATLANTIQUE NORD CARAIBES MER 032 064 021 682 113461 [11 p.] 2026 0031-0182 https://www.documentation.ird.fr/hor/fdi:010095903 10.1016/j.palaeo.2025.113461 0031-0182 [F B010095903] https://www.documentation.ird.fr/hor/fdi:010095903 https://www.documentation.ird.fr/intranet/publi/2026-01/010095903.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2026-01-14 2026-01-14 fdi:010095903 fre