The pattern of anthropogenic signal emergence in Greenland

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 (Gr. IS) surface mass balance (SMB) are related to anthropogenic forcing. To explore this issue, we analyze the spatial pattern of an anthropogenic signal in Gr. IS SMB. Approach • Analyzed SMB from fully-coupled CESM 1850 -2100 simulation • Used a signal-to-noise approach to identify time of emergence of anthropogenic Gr. IS SMB signal at each ice sheet grid point • Analyzed emergence timing in the context of physical processes related to Gr. IS SMB Direction and spatial pattern of anthropogenic signal emergence signal in Gr. IS SMB. Blue indicates upward emergence due to increased snowfall, red indicates downward emergence due to increased melting, and grey indicates regions with no emergence. Impact Early signal emergence in Gr. IS 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 Gr. IS SMB in the 21 st 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. 1002/2014 GL 060735