Small impact of surrounding oceanic conditions on 2007–2012 Greenland Ice Sheet surface mass balance
B. Noël1,2, X. Fettweis1, W. J. van de Berg2, M. R. van den Broeke2, and M. Erpicum1 1Department of Geography, University of Liège, Belgium 2Institute for Marine and Atmospheric research Utrecht, University of Utrecht, the Netherlands
Abstract. During recent summers (2007–2012), several surface melt records were broken over the Greenland Ice Sheet (GrIS). The extreme summer melt resulted in part from a persistent negative phase of the North-Atlantic Oscillation (NAO), favouring warmer than normal conditions over the GrIS. In addition, it has been suggested that significant anomalies in sea ice cover (SIC) and sea surface temperature (SST) may partially explain recent anomalous GrIS surface melt. To assess the impact of 2007–2012 SIC and SST anomalies on GrIS surface mass balance (SMB), a set of sensitivity experiments was carried out with the regional climate model MAR. These simulations suggest that changes in SST and SIC in the seas surrounding Greenland do not significantly impact GrIS SMB, due to the katabatic winds blocking effect. These winds are strong enough to prevent oceanic near-surface air, influenced by SIC and SST variability, from penetrating far inland. Therefore, the ice sheet SMB response is restricted to coastal regions, where katabatic winds are weaker. However, anomalies in SIC and SST could have indirectly affected the surface melt by changing the general circulation in the North Atlantic region, favouring more frequent warm air advection to the GrIS.
Citation: Noël, B., Fettweis, X., van de Berg, W. J., van den Broeke, M. R., and Erpicum, M.: Small impact of surrounding oceanic conditions on 2007–2012 Greenland Ice Sheet surface