Warmer-than-usual temperatures in Antarctica (1.5 degrees Celsius above normal, on average across the continent and upwards of 3 degrees Celsius above normal in the Peninsula) are having an impact not only on sea ice melt, glacial melt, and snow melt this season. They’re also allowing for the proliferation of algae in the Antarctic Peninsula, causing the snow and ice to melt faster than it would otherwise. Warming is likely expanding and strengthening the snow algal bloom season and is projected to continue, so long as temperatures remain warmer than usual.
Pictured here is Chlamydonomas nivalis, a species of green algae that, in addition to chlorophyll, has a secondary red pigment that acts like a sunscreen against intense UV radiation. This ensures that it survives through the next season. Algal blooms are linked to availability of sunlight (to be able to photosynthesize), water, and nutrients, where the latter come from waste, like penguin poop. Green algae has been measured and found to reduce the albedo (reflectivity of snow and ice) by 40%, while the red algae can drop reflectivity by 20%. The green algae has more of an impact on the albedo due to the presence of more chlorophyll, which absorbs more radiation. The significance is that, in the Antarctic Peninsula, algal blooms like these can result in over a million gallons of additional snow melt per year.
photo: Ulyana Peña, in February 2023