Impact of variable fjord/shelf exchange on glacial dynamics in SE Greenland.

The observed acceleration and retreat of southeast Greenland's major outlet glaciers in the last two decades is thought to have been influenced significantly by oceanic heating. Within the last decade, obervations from the region indicate that the dominant control on along-fjord heat flux is the intermediary circulation driven by wind-induced baroclinic pressure gradients between fjord and shelf. This mechanism conflicts with the classical theory whereby warm shelf water is drawn into the fjord through estuarine circulation driven by freshwater runoff at the terminus, both on the surface and at depth.

Here, preliminary results from an MITgcm numerical modelling study of fjord/shelf interaction in southeast Greenland's Kangerdlugssuaq Fjord are presented. Using idealized wind and boundary forcings in a realistic bathymetric setting, the strength of intermediary circulation in the region is studied quantitively. Sub-glacial runoff is incorporated using a plume parameterisation package, allowing the bulk effects to be captured without the need to simulate a turbulent plume.