No, it's not ice sherbet. But this blanket of pink snow — which scientists say is actually red-pigmented, snow-dwelling algae — is known in some places as "watermelon snow."
Although it is not edible, the presence of watermelon snow is very crucial, and it has been vastly underestimated in the past, new research suggests.
Now, scientists are concerned because they have discovered that snow alga plays a role in climate change: it can accelerate the melting of Arctic glaciers.
How Snow Algae Speed Up Arctic Glacier Melting
In the new study, researchers analyzed red snow algae located across 21 glaciers in the pan-European Arctic.
They found that these tiny organisms accelerate the melting of snow, and it has something to do with a simple process known as the "albedo" affect.
Glaciers are important, as they reflect sunlight and help keep our planet cool. However, as glaciers melt, it paves the way for darker land or ocean surfaces — surfaces that have lower albedo.
Here's where the algae come in: these microscopic creatures often lie dormant in the snow during winter but blossom into pink landscapes once late spring and summer rolls in.
The algae are typically green, but they produce a natural sunscreen that paints the snow pink and red.
Scientists say that this addition of color to the surface darkens the snow, heats it up faster, and causes it to melt more quickly.
Geobiologist Stefanie Lutz compares it to wearing a black T-shirt instead of a white one under the sun. Doing so absorbs more heat.
"It is the same for the snow," Lutz tells The New York Times. "More heat means more melting."
Lutz and her colleagues found that red algae reduce the albedo of the snow they colonize by as much as 13 percent.
And although scientists have yet to determine how large the algal bloom can get, Lutz says they can become quite widespread in the Arctic during summer.
"A conservative estimate would be 50 percent of the snow surface on a glacier at the end of a melt season," Lutz tells Gizmodo. But this can turn up much higher.
Why You Should Care
What Lutz and her team are concerned about is that if red snow algae can have a small influence on Arctic glaciers today, their role can possibly grow as human carbon emissions increasingly warm the planet.
Because the red algae need liquid water to bloom, the melting of glacier and snow controls the abundance of these organisms.
Lutz says the more melting, the more algae there will be. And with average global temperatures rising, the snow algae phenomenon may potentially increase and result in an even greater bio-albedo effect.
Details of the study are featured in the journal Nature Communications.
