Algae Blooms Increase Snowmelt In The Pacific Northwest By 20%

Algae that commonly grow on snow in the Pacific Northwest have been ignored in melt models, but their presence significantly increases snowmelt compared with clean, white snow, according to a study conducted on Mount Baker in the North Cascades, Washington.

Scientist Alia Khan at Western Washington University and the National Snow and Ice Data Center at the University of Colorado Boulder, is the senior author of the study. Clean snow reflects as much as 99% of incoming solar radiation, helping to protect Earth's atmosphere from warming.

Algae, usually a red color, often bloom on snow in the summer months in the Pacific Northwest. They cause the albedo, or reflectivity, of the snow to decrease by about 20%. That energy is absorbed rather than reflected to space because of the algae's darker color. Results of the U.S. National Science Foundation-supported study were published in Nature Communications Earth & Environment .