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Publication Date
9 April 2024

Sensitivities of the West Greenland Current to Greenland Ice Sheet Meltwater in a Mesoscale Ocean/Sea Ice Model

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To understand changes in ocean circulation over the West Greenland continental shelf/slope and in the eastern Labrador Sea from the release of Greenland Ice Sheet meltwater.


As depicted by a suite of ocean/sea-ice simulations, meltwater released from the Greenland Ice Sheet (GrIS) increases the speed of the West Greenland continental shelf/slope currents and enhances cross-shelf freshwater fluxes and freshwater volume in the eastern Labrador Sea. All are sensitive to the form in which meltwater is released at the Greenland coast with the greatest responses occurring when the GrIS meltwater is vertically distributed over the upper water column. These results have implications for the simulation of Labrador Sea freshening and deep convection.


A suite of simulations using an atmospheric reanalysis forced ultra-high (~2-3 km in the study region) resolution global ocean-sea ice model is used to investigate the sensitivity of the ocean circulation over the West Greenland continental shelf/slope and in the eastern Labrador Sea to meltwater perturbations from the Greenland Ice Sheet (GrIS). The simulations have: 1) no meltwater (control), (2) meltwater released at the ocean surface (as is standard in forced ocean/sea-ice models), and (3) meltwater vertically distributed over the top 200 m to account for mixing within fjords. In the presence of meltwater, the West Greenland and West Greenland Coastal Currents are faster in the two meltwater perturbation cases than in the control; their mean surface speeds are highest in (3). Relative to the control, cross-shelf fluxes of freshwater into the Labrador Sea increase in the Ekman layer in (2) and due to enhanced baroclinic conversion/eddy formation over the upper water column in (3). These cross-shelf fluxes are greater in (3) than (2). In addition, in the eastern Labrador Sea, the salinity is lowest, and the meltwater volume is greatest in (3). Therefore, West Greenland continental shelf/slope currents and the salinity of the eastern Labrador Sea are sensitive to how meltwater is added to ocean models.

Point of Contact
Julie McClean
Scripps Institution of Oceanography
Funding Program Area(s)
Additional Resources:
ALCC (ASCR Leadership Computing Challenge)
NERSC (National Energy Research Scientific Computing Center)