Abstract

Recent studies have suggested that regional changes in ocean temperatures could be a potential trigger for retreat and acceleration of Greenland tidewater outlet glaciers. There is therefore a need to understand how these changes are propagated along fjords to the glaciers’ calving termini. We use the Bergen Ocean Model to simulate ocean circulation in Kangerdlugssuaq Fjord to assess the impact that warmer coastal waters and increased supra-glacial run-off could have on the submarine melt rate of Kangerdlugssuaq Gletscher. The model includes tidal and freshwater runoff forcing and is able to replicate well observed temperature and salinity profiles. We find that warm coastal water flows into the fjord at several distinct depths as a result of freshwater outflow near the surface and at intermediate depth. The deeper (~400m) warm water plume reaches the terminus of Kangerdlugssuaq Gletscher and increases submarine melt rates. The magnitude of supraglacial runoff is crucial in controlling the penetration of warm water into the fjord because of the compensatory inflow at depth.