By Michael Marshall
Part of Antarctica is already green due to blooms of algae living on the snow. As the continent warms, more of it may turn green, but it isn’t clear what this will mean for the climate.
Patches of “snow algae” have been known about for decades in the Arctic. But we know much less about their distribution in Antarctica. “Our work was really the first large-scale survey of snow algae for Antarctica,” says Andrew Gray at the University of Cambridge.
Gray and his colleagues used satellite images to identify patches of green on the snow-covered surface of the Antarctic Peninsula, the part of the continent that is warming the fastest, and the islands nearby. They also visited two islands to confirm the satellite data’s reliability.
The researchers found that in total, there were 1679 blooms of snow algae that covered up to 1.9 square kilometres at the height of summer when the blooms are largest. Two factors seemed to determine where the blooms were: the temperature had to be warm enough for the snow to become slushy and there had to be a source of nutrients – mostly penguin guano.
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