In February — summer in Antarctica — blood-red snow appeared across the Antarctic Peninsula. Snow and ice around Ukraine’s Vernadsky Research Base on Galindez Island was covered with what is called “raspberry snow”, “watermelon snow”, or “blood snow” (Figures 1 and 2). This is not a new phenomenon. In fact, it was noticed by Aristotle back in the third century B.C. The red coloring is a type of alga that can be found in snowfields and mountains worldwide. The algae live in freezing water but are dormant during the winter. In summer when the snow melts, the algae bloom with red, flower-like spores. As with soot on snow, the algae can cause a positive feedback where algae darkens the surface causing more solar radiation to be absorbed, which in turn warms the surface and causes more melt and more algae.

Figure 1: The ice around Ukraine’s Vernadsky Research Base, located on Galindez Island, off the coast of Antarctica. Copyright Andrey Zotov, from Euronews)
Figure 2: Blood snow at Vernadsky Research Base showing surface coverage and layering. Copyright Andrey Zotov, from Facebook)

Credit: Marine ecologist Andrey Zotov from the National Academy of Sciences of Ukraine took the pictures above. News coverage: Euronews, ScienceAlert, and elsewhere.