Pink snow, also called "watermelon snow," has appeared at Northern Italy's Presena glacier, according to Biagio Di Mauro of the Institute of Polar Sciences at Italy's National Research Council. While it's not uncommon for the Italian Alps to be "pretty in pink" in spring and summer, scientists become cautious when the phenomenon, which is caused by algae, starts happening more frequently.
Biagio Di Mauro, of the Institute of Polar Sciences (ISP) at Italy's National Research Council, traveled to the glacier last week to investigate the mysterious algae. While the phenomenon is well-documented, "there is relatively little scientific literature on this phenomenon, which has the direct effect of accelerating the melting of snow and ice," the institute said. The algae could accelerate melting in the already fragile region. Climate change, contributing to 2020's unseasonably warm temperatures and lack of snow, is exacerbating the issue.
Typically, ice reflects the majority of the sun's radiation, but algae darken the ice, causing a decrease in albedo, or reflectivity. This causes the snow to absorb more heat and melt more quickly. "Everything that darkens the snow causes it to melt because it accelerates the absorption of radiation," said Di Mauro. In order to flourish, the organisms need an available supply of water. So, as the ice melts, even more algae will appear.
The concern is that the algal bloom on the snow will accelerate the effects of the climate crisis. As Agence France-Presse (AFP) reported the plant, known as Ancylonema nordenskioeldii, is often found in Greenland's so-called Dark Zone, where the ice is also melting.
"A classic reminder of how uncertainty is not our friend," said Dr. Michael E. Mann, a distinguished professor of atmospheric science at Penn State University, to Salon by email. "In this case, we're seeing an amplifying feedback wherein biological darkening (due to Algae growing on the surface of melting ice), leads to more solar absorption by the ice and even faster melting. We call this a 'positive feedback' but it is anything but positive. It reflects a process which is leading to faster melting of the glaciers than our simple models predict."
Scientists are now trying to understand how the melting of ice at such unexplored regions and for reasons yet undiscovered is having an impact on global sea level rise. A recent study in this regard measures the ice melt from below the ice shelves of Antarctica.