MAGEHC: Actividad a mesoescala en el corredor de remolinos entre la Gomera y el Hierro: Impactos en la hidrografía y la biogeoquímica regional

The MAGEHC project (Mesoscale Activity in the Gomera–El Hierro Corridor) aims to advance understanding of how semi-static mesoscale eddies and associated submesoscale processes influence regional hydrography, plankton dynamics, and the Biological Carbon Pump (BCP) in the Canary Islands. While mesoscale eddies are known to play a key role in ocean productivity and carbon sequestration, their life-cycle evolution, interaction with submesoscale dynamics, and biogeochemical impacts remain poorly constrained, particularly in regions dominated by island–current interactions.

Recent observations in the Gomera–El Hierro corridor have revealed the presence of semi-static cyclonic eddies with exceptionally high primary production, in some cases exceeding that of propagating eddies by up to two orders of magnitude. These features appear to be generated by island–current interactions and subsequently trapped by the presence of El Hierro, allowing sustained physical forcing, enhanced nutrient supply to the euphotic zone, and intensified biological responses. The mechanisms underpinning their formation, persistence, and decay, as well as their contribution to carbon export and sequestration, remain unknown.

MAGEHC addresses this knowledge gap through an integrated observational and modelling strategy combining satellite remote sensing, autonomous ocean gliders, Biogeochemical Argo floats, and a high-resolution coupled physical–biogeochemical regional model. Three multi-week glider missions will provide unprecedented spatial and temporal resolution of hydrographic, biological, and particle fields across the full life cycle of these eddies. These observations will be complemented by historical data mining and near-real-time satellite monitoring to guide field operations and support model validation.

The project’s central hypothesis is that the interaction between island-generated mesoscale eddies and submesoscale processes enhances vertical nutrient transport, stimulates phytoplankton growth dominated by larger taxa, and promotes efficient downward transport of particulate organic carbon, thereby strengthening the regional BCP. By resolving processes from the mesoscale down to the submesoscale, MAGEHC will quantify how physical forcing, biological production, and carbon fluxes are dynamically coupled.

Although conceived as a basic research project with no immediate socio-economic outputs, MAGEHC will generate transferable knowledge relevant to fisheries management, ecosystem forecasting, and climate-driven projections of ocean productivity. Its results will be disseminated through open-access publications, international conferences, public databases, and outreach activities, contributing to a broader understanding of how fine-scale ocean dynamics regulate marine ecosystems and carbon cycling in eastern boundary current systems.