The presence of large quantities of red pigmented snow algae blooming on icy surfaces leads to a darkening the surface. This darkening effect reduces albedo and this results in a higher uptake of heat. Albedo refers to the proportion of the incident light or radiation that is reflected by a surface. This effect occurs most often during the warmer months, when algal growth is at its highest.
The growth patterns of the algae were observed through sampling and advanced genetic sequencing techniques. Samples were collected from 21 glaciers in the Pan-European Arctic, including Greenland, Sweden and Iceland.
The research found an inter-relationship
between the levels of algae and the rate of ice melting. This means, the more glaciers and snow fields thaw the more algae bloom which in turn results in a darkening of the surface which again accelerates melting. During the summer, the sun is warm enough to cause a slight melting of the surface layers, and this provides the algae with the liquid water they need. Dust, brought by the wind, supplies the necessary minerals.
These findings stem from a study conducted by the German Research Centre for Geosciences GFZ and at the University of Leeds, U.K. In a statement the lead researcher, Dr. Stefanie Lutz said: “Our results point out that the "bio-albedo" effect is important and has to be considered in future climate models.”
It is hoped that the research provides the basis for a model for better understanding the rate of melting and the risks stemming from climate change. On hearing this, environmentalist Joseph Cook (@tothepoles) tweeted
: "Bioalbedo article feat. many @Glacier_Albedo ppl explains concept and highlights important Qu's that need attention."
The algae is an organism called Chlamydomonas nivalis
. This is a species of green algae that contains a secondary red carotenoid pigment (astaxanthin) in addition to chlorophyll. This, under certain circumstances, leads to the red color.
The research into the algae has been published in the journal Nature Communications
. The research paper is titled “The Biogeography of Red Snow Microbiomes and their Role in Melting Arctic Glaciers.”