Pretty pink snow actually a terrible sign for glaciers
Digital Reporter
Friday, June 24, 2016, 11:53 AM - You might be seeing a great deal more pink snow on the Arctic's glaciers. But for climate scientists, it's anything but a fairytale.
The reddish tinge to snow on some glacers, observed in warmer months, is actually pretty normal. They're indicative of algae that lie dormant in the ice during the winter, then spring back to life in the meltwater formed as the spring and summer sun shines on them.
However, researchers in Germany and the U.K. say the red algae have a bigger role in climate change than originally thought.
Image: Liane G. Benning, GFZ.
As global temperatures rise, and there's more glacial melt, you'll likely be seeing more of the algae. That's a problem, because the reddish tinge has the effect of lowering a glacier's albedo, the measure of its reflectivity.
The darker a glacier is, the lower its albedo, and the more sunlight it absorbs rather than reflects. That kicks off a positive feedback loop: Warmer temperatures cause more meltwater, meaning more algae, which heat up glaciers faster, leading to more melting.
The authors of the report, which was published in the journal Nature Communications this week, say that plunge in reflectivity can be as much as 13 per cent in a season.
Image: Liane G. Benning, GFZ.
"Our results point out that the “bio-albedo” effect is important and has to be considered in future climate models," lead author Stefanie Lutz said in a release from the German Research Centre for Geosciences GFZ.
The team's study involving taking about 40 samples from 21 glaciers in the Arctic, including sites in Greenland, Iceland, northern Sweden, and the Norwegian Arctic island territory of Svalbard.
SOURCE: German Research Centre for Geosciences GFZ | Nature Communications
