“SNICAR-ADv4: a physically based radiative transfer model to represent the spectral albedo of glacier ice”

Modeling Bare Ice and Glacier Algae Albedo


The Greenland Ice Sheet is melting at unprecedented rates. More than half of this melt can be attributed to surface melt processes, rather than caving events. The melt of the ice sheet surface is modulated by the albedo, or how reflective, the surface is. If the surface is white and highly reflective (high albedo) more energy is reflected back to space and less energy is absorbed to contribute to ice melt. However, as we are seeing warmer temperatures over the ice sheet, we are also seeing larger areas of dark bare ice exposed for longer periods of the melt season. Recently darkly pigmented algae have been found to colonize these bare ice areas on the ice sheet. These algae have dark pigments that act as a sunscreen to cover and protect their organelles, they also absorb sunlight and melt the surrounding ice which releases dust and other nutrients from the ice, creating a positive feedback between algal growth and surface melt. The exposure of bare ice and growth of glacier algae are two phenomenon that are not well represented in climate models. We are working to develop physically based models that accurately represent the influence bare ice and glacier algae have on the albedo of the Greenland Ice Sheet so we can quantify their contribution to the global radiative budget and sea level rise.


Contact

164 Rowland Hall
University of California, Irvine
Irvine, CA 92697-4675

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