There is a lot of greenery around Antarctica - you just need to know where and when to look. During the Antarctic spring and summer, coastal waters can be covered with bright emerald-turquoise swirls. These are phytoplankton - floating microscopic plant organisms.
A wild bloom of phytoplankton in Terra Nova Bay and McMurdo Sound was captured on January 21, 2020 by NASA's Aqua satellite. Similar colorful eddies in coastal waters are sometimes formed by precipitation raised from the bottom by waves and currents. But scientists say the source of the color this month is biological.
“It's definitely phytoplankton that tends to bloom every January in Terra Nova Bay,” said Kevin Arrigo, a biological oceanographer at Stanford University. His colleague Robert Dunbar agrees: "This phenomenon is characteristic of the coastal polynyas of Antarctica in summer."
Polynyas are areas with an abundance of sunlight and near-surface nutrients, making them a refuge for phytoplankton. Blooming in polynyas can be observed even at the end of the Antarctic summer, in February or March, when the water is covered with sludge crystals and pancake ice. This can be seen in a photograph taken in 2018.
In the January satellite image, part of the bloom appears to be also associated with sea ice, primarily to the north of the Drygalski ice tongue. But everything else in McMurdo Sound is typical summer bloom.