Two coupled ocean-sea ice simulations that partially resolve mesoscale eddies, one global and one of the Pan-Arctic region, are used to understand the magnitudes, variability, and causes of the delivery of warm water originating in the North Atlantic onto the southern Greenland continental shelf.
Warm salty water originating from the North Atlantic Ocean is delivered to the southeastern Greenland continental shelf south of the Denmark Strait. These warm waters have been implicated in melting at the margins of the Greenland Ice Sheet in the Greenland fjords. Understanding the amount, the location, and how the heat is delivered to the Greenland fjords is necessary to predict the likely contribution of a warming ocean to overall GIS melt.
Two coupled ocean-sea ice simulations are used to understand the strength, variability, and causes of cross-shelf fluxes of heat over the southern Greenland continental shelf. The simulations are generated by a global 1/10° configuration of the Parallel Ocean Program (POP) and a 1/12° Pan-Arctic configuration of the HYbrid Coordinate Ocean Model (HYCOM). Differences in the shelf break circulation and on-shelf heat content are identified between the two simulations. The largest onshore heat flux occurs over the southeast Greenland shelf. Here, in HYCOM, onshore heat flux is associated with the mean flow whereas in POP it is associated with mesoscale eddies. A seasonally persistent pattern of multi-day variability in the cross-shelf heat flux is found south of the Denmark Strait in both simulations. In the POP simulation, this high-frequency signal results in net on-shore heat flux. In HYCOM, the signal is weaker and results in net off-shelf heat flux. This variability is consistent with Denmark Strait Overflow eddies traveling along the shelf break.