The objective is to demonstrate that spatially variable ice-surface roughness is an important, and so far overlooked, component of melt processes in the Greenland Ice Sheet (GrIS), linking the analysis of spatial ice-surface roughness (SISR) derived from satellite laser altimeter data with essential components of surface energy balance modeling, particularly of sensible heat flux. Specific results are: (1) SISR can be calculated from ICESat Geoscience Laser Altimeter System (GLAS) data for the G