The Greenland Ice Sheet is melting faster as its surface becomes darker and reflects less sunlight. The study shows that the length of time bare ice is exposed during summer is a strong indicator of how dark the ice sheet becomes. The longer the ice remains exposed, the more sunlight it absorbs, leading to increased melting. Using weather station measurements and satellite observations across Greenland, we found that even small decreases in surface reflectivity can significantly increase seasonal ice loss. These findings improve our understanding of the processes driving Greenland's melt and highlight the growing importance of ice-sheet darkening in a warming climate, where longer melt seasons and larger areas of exposed ice are expected.

Link to paper: Journal of Geophysical Research: Earth Surface, 131, e2026JF009204. doi.org/10.1029/2026JF009204