Over the last few weeks, photographs of “red snow” off the coast of Antarctica’s northernmost peninsula, have gone viral. “Red snow” or “watermelon” is a phenomenon that has been known since ancient times. Now, it raises concerns about climate change.
Red snow in Antarctica: Why it happens
- Aristotle is believed to be one of the first to give a written account of red snow, over 2,000 years ago.
- What Aristotle described as worms and grub, the scientific world today calls algae.
- This alga species, Chlamydomonas Chlamydomonas nivalis, exists in the snow in the polar and glacial regions and carries a red pigment to keep itself warm.
Signs of faster melting
- In turn, the red snow causes the surrounding ice to melt faster. The more the algae packed together, the redder the snow.
- And the darker the tinge, the more the heat absorbed by the snow. Subsequently, the ice melts faster.
- While the melt is good for the microbes that need the liquid water to survive and thrive, it’s bad for glaciers that are already melting from a myriad of other causes, the study said.
- These algae change the snow’s albedo — which refers to the amount of light or radiation the snow surface is able to reflect back. Changes in albedo lead to more melting.
