Woods Hole Oceanographic Institution

Claudia Cenedese

»Downwelling in Basins Subject to Buoyancy Loss
»Entrainment and mixing dynamics of surface-stress-driven stratifi ed flow in a cylinder
»Laboratory experiments on two coalescing axisymmetric turbulent plumes in a rotating fluid
»Impact of fjord dynamics and glacial runoff on the circulation near Helheim Glacier
»The relationship between flux coefficient and entrainment ratio in density currents
»A new parameterization for entrainment in overflows
»Laboratory experiments on the interaction of a buoyant coastal current with a canyon: application to the East Greenland Current
»Variations in ocean surface temperature due to near surface flow: straining the cool skin layer
»Mixing in a density-driven current flowing down a slope in a rotating fluid
»Laboratory experiments on mesoscale vortices colliding with an island chain
»Laboratory observations of enhanced entrainment in dense overflows in the presence of submarine canyons and ridges
»How entraining density currents influence the stratification in a one-dimensional ocean basin
»Laboratory experiments on eddy generation by a buoyant coastal current flowing over variable bathymetry
»Laboratory experiments on mesoscale vortices interacting with two islands
»Variability of Antarctic bottom water flow into the North Atlantic
»Laboratory experiments on a mesoscale vortex colliding with topography of varying geometry in a rotating fluid
»A laboratory model of thermocline depth and exchange fluxes across circumpolar fronts
»A dense current flowing down a sloping bottom in a rotating fluid
»Laboratory experiments on mesoscale vortices colliding with a seamount
»Stability of a buoyancy-driven coastal current at the shelf break
»Eddy-shedding from a boundary current around a cape over a sloping bottom
»Cyclone and anticyclone asymmetry in a rotating stratified fluid over bottom topography

Straneo F., Curry, R.G., Sutherland D.A., Hamilton G.S., Cenedese C., Våge K. and Stearns L.A., Impact of fjord dynamics and glacial runoff on the circulation near Helheim Glacier, Nature Geosciences, doi: 10.1038/NGEO1109, 2011

Submarine melting is an important contributor to the mass balance of tidewater glaciers in Greenland, and has been suggested as a trigger for their widespread acceleration. Our understanding of this process is limited, however. It generally relies on the simplified model of subglacial discharge in a homogeneous ocean, where the melting circulation consists of an entraining, buoyant plume at the ice edge, inflow of ocean water at depth, and outflow of a mixture of glacial meltwater and ocean water at the surface. Here, we use oceanographic data collected in August 2009 and March 2010 at the margins of Helheim Glacier, Greenland to showthat the melting circulation is affected by seasonal runoff from the glacier and by the fjord’s externally forced currents and stratification. The presence of light Arctic and dense Atlantic waters in the fjord, in particular, causes meltwater to be exported at depth, and influences the vertical distribution of heat along the ice margin. Our results indicate that the melting circulation is more complex than hypothesized and influenced by multiple external parameters.We conclude that the shape and stability of Greenland’s glaciers may be strongly influenced by the layering of the Arctic and Atlantic waters in the fjord, as well as their variability.

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