Abstract

The rapid melting of the Greenland Ice Sheet and the associated sea level rise is controlled by changes in albedo, which is primarily a consequence of increased light absorbing particulates (LAP) on snow and ice surfaces. Among LAPs, and included in climate models is black carbon. However, other LAPs so far not included in climate models because their role is poorly quantified, are mineral dust and pigmented glacier algae. We will show pigmented algae can reduce albedo by up to ~ 20 %, and that a necessary interplay between geochemical, mineralogical and microbiological parameters helps trigger the annual mineral-nutrient fuelled glacial algal blooms. We ground truth and link surface, airborne and satellite data and determine the role and consequences of water-mineral-microbe interface reactions in shaping large-scale processes across the Greenland Ice Sheet.