Role of atmospheric feedbacks in the ocean’s response to enhanced Greenland Ice Sheet–melting
These systematic experiments are used to discuss the role of atmospheric feedbacks in setting the North Atlantic’s sensitivity to enhanced Greenland Ice Sheet–melt. Seasonality likely plays a major role in the ocean’s sensitivity to meltwater but also atmospheric feedbacks. Meltwater runoff peaks in summer, which is maintained in our experiments. We find an annual maximum of meltwater concentration in the adjacent seas in early fall, a realistic delay. In the subpolar gyre region, the strongest reduction in surface heat fluxes (-30%) is found in late fall/early winter, a change occurring already during the first decade with enhanced runoff. Simultaneously, precipitation increases significantly, almost doubles in the gyre center on long-term mean. Both changes act together in stabilizing the local stratification and inhibiting the important preconditioning for open ocean deep convection in the Labrador Sea in winter. While the reduced heat flux is a feature of both, coupled and forced experiments, the increased precipitation is only found in the coupled simulation.