Mesoscale ocean dynamics drive chlorophyll-a distribution in the Caribbean Sea

Mesoscale ocean dynamics are key contributors of chlorophyll-a (Chl-a) variability and thus of primary production and biogeochemical cycling. In regions with strong mesoscale activity such as the Caribbean Sea, fluctuations in eddy kinetic energy (EKE) may influence the spatial organization of surface Chl-a patterns. However, the limited availability of field observations of Chl-a variability in the Caribbean across space and time makes it difficult to evaluate this relationship. This study therefore combines satellite-derived Chl-a data, surface current velocity fields, and self-organizing maps to examine whether EKE and seasonal processes are associated with the spatial distribution of Chl-a across the basin scale. Nine spatial regions were identified from the Chl-a SOM regionalization, reflecting the influence of coastal upwelling and riverine inputs. Regions influenced by the Orinoco and Amazon plumes exhibit relatively elevated Chl-a levels, whereas offshore sectors such as the Yucatan and Cayman basins show lower concentrations. A complementary Chl-a–EKE dual-SOM analysis revealed sixteen recurrent coupled bio-physical regimes associated with mesoscale variability. These results highlight the role of mesoscale circulation in structuring surface Chl-a patterns across the Caribbean Sea and provide a pattern-based framework that can guide future studies aimed at identifying the mechanistic links between mesoscale dynamics, biological variability, and carbon cycling in oligotrophic marine ecosystems. • Self-organizing maps identify coherent basin-scale patterns of chlorophyll-a variability in the Caribbean Sea. • Regional contrasts emerge between coastal and offshore chlorophyll-a regimes. • Dual-SOM analysis links chlorophyll-a variability with mesoscale dynamical variability (EKE). • Mesoscale circulation patterns are closely associated with the spatial organization of chlorophyll-a.