Objective

1. The pattern of anthropogenic signal emergence in Greenland Ice Sheet surface mass balance Objective It is not clear how recent record melt events and long-term observed trends in Greenland Ice Sheet (GrIS) surface mass balance (SMB) are related to anthropogenic forcing. To explore this issue, we analyze the spatial pattern of an anthropogenic signal in GrIS SMB. Direction and spatial pattern of anthropogenic signal emergence signal in GrIS SMB. Blue indicates upward emergence due to increased snowfall, red indicates downward emergence due to increased melting, and grey indicates regions with no emergence. • Approach • Analyzed SMB from fully-coupled CESM 1850-2100 simulation • Used a signal-to-noise approach to identify time of emergence of anthropogenic GrIS SMB signal at each ice sheet grid point • Analyzed emergence timing in the context of physical processes related to GrIS SMB Impact Early signal emergence in GrIS SMB occurs downwards around the ice sheet margins and upwards in the ice sheet interior, with emergence already underway at the present-day in both locations. An anthropogenic signal will be a dominant aspect of GrIS SMB in the 21st century. Fyke, J.G., M. Vizcaíno, W.H. Lipscomb: The pattern of anthropogenic signal emergence in Greenland Ice Sheet surface mass balance. Geophysical Research Letters, 10.1002/2014GL060735