20.05.2022

​​‘Watermelon Snow’ Is Pink and Pretty, But It Signals Disaster

It's also known as blood snow, pink snow, or red snow. Otherwise known as glacier blood, watermelon snow is found worldwide in mountains and polar regions. The pink-red snow has a faintly fruity smell but is reported to have laxative effects if eaten. The watermelon colour comes from freshwater green algae called Chlamydomonas nivalis. In summer, the algae produce a red pigment to protect themselves from the Sun’s intense rays. Unfortunately, the pigment reduces snow’s ability to reflect heat, leading to faster melting rates. The red coloring of the algae organisms also has other effects. It causes the snow to melt more quickly, which releases more water that the algae need to survive. On Alaska’s Harding Ice-field, these microbes are responsible for about a sixth of the snow-melt in algae-tinged areas, researchers report September 21 in Nature Geoscience. The finding suggests that future climate simulations, unlike current ones, should account for the effects of these algae when making predictions about glacial melt. Over 100 days, the scientists tracked how much the zones melted. Places with extra algae melted much faster than areas where algae had been stripped away — they were three times as likely to melt down to slush or exposed ice by the end of the test.
Credit: Brut.