AMOC Restoration through Spatially Targeted Geoengineering Technologies

The Atlantic Meridional Overturning Circulation (AMOC) is at risk of significant weakening or collapse due to freshwater input from Greenland ice sheet melt and Arctic sea-ice loss. Stable surface freshwater lenses formed in this process suppress deep convection in the Labrador and Irminger Seas. Unlike existing geoengineering proposals that require enormous costs or intervene in global atmospheric processes, this work presents a spatially targeted, locally applied, and relatively low-cost alternative : deliberate modification of the freshwater export regime from Greenland fjords to promote vertical mixing rather than surface stratification. By deploying floating curtains in the mouths of selected fjords (partially blocking the upper 50 m while allowing turbulent exchange at depth), seasonal pulsed surface runoff can be transformed into a quasi-continuous, vertically mixed outflow. The denser (more saline) outflow during ebb tide generates density anomalies that initiate mesoscale anticyclonic vortices through baroclinic instability, leading to local surface salinization, Ekman convergence, thinning of the freshwater cap, and preconditioning for renewed deep winter convection in the Labrador Sea. The proposed mechanism harnesses the potential energy of freshwater runoff and tidal energy to drive saltwater upwelling in mixed plumes, thereby destabilizing stratification. If validated through pilot experiments, such local interventions could contribute to stabilizing deep convection and supporting AMOC recovery.