Antarctica conjures images of an unbroken white wilderness but blooms of algae are giving parts of the frozen continent an increasingly green tinge. Parts of the Antarctic Peninsula will change color as “green snow” caused by blooming algae is expected to spread with increases in global temperatures, research showed.
The green snow algae are microscopic organisms when measured individually but when the organisms grow simultaneously, they turn the snow bright green. Warming temperatures due to climate change are helping the formation and spread of “green snow” and it is becoming so prolific in places that it is even visible from space.
Now, using data collected over two years by the European Space Agency’s Sentinel 2 satellite, together with on-the-ground observations, a research team from the University of Cambridge and the British Antarctic Survey have created the first map of the algae blooms on the Antarctic Peninsula coast. It was gathering satellite data of over two summers in Antarctica between 2017 and 2019.
The study added that the warmer areas in the Antarctic coastline are usually seen with patches of the green snow algae. The average temperature in the coastline is little above zero degrees celsius during the Southern Hemisphere’s summer months of November to February. Mosses and lichens are considered the dominant photosynthetic organisms in Antarctica – but the new mapping found 1,679 separate algal blooms that are a key component in the continent’s ability to capture carbon dioxide from the atmosphere. They also found that the majority of algae blooms were within five kilometers (three miles) of a penguin colony, as the birds’ excrement is an excellent fertilizer.
The researchers further marked out that the Antarctic Peninsula is part of the region that has experienced the most rapid warming in the latter part of the last century. High temperatures were recorded in February and a nine-day heatwave burnt the continent’s northern tip earlier this year. They identified more than 1,600 separate green algae blooms on snow across the peninsula, with a combined surface area of 1.9 square kilometers. It is calculated that algae on the peninsula currently absorb levels of CO2 equivalent to 875,000 average car journeys.