Thinning ice creates undersea Arctic greenhouses
Light shining through could increasingly let phytoplankton bloom in polar region
GREEN LIGHT The thinning and melting of Arctic sea ice allows more light to reach the waters below, which may spawn more and more phytoplankton blooms (right). Typically the thick, opaque ice prevents the blooms, which can consist of diatoms such as these (left).
William M. Balch/Bigelow Laboratory for Ocean Sciences; Karen Frey/Clark Univ.
Sea ice skylights formed by warming Arctic temperatures increasingly allow enough sunlight into the waters below to spur phytoplankton blooms, new research suggests. Such conditions, probably a rarity more than two decades ago, now extend to roughly 30 percent of the ice-covered Arctic Ocean during July, researchers report March 29 in Science Advances.
The microscopic critters need plenty of sunlight to thrive, so scientists were stunned by the discovery of a sprawling bloom below the normally sun-blocking Arctic ice in July 2011 (SN: 7/28/12, p. 17). Satellites can’t peek below the ice, though, so scientists at the time didn’t know whether the bloom was an oddity or representative of a shift in the Arctic environment.
Harvard University oceanographer Christopher Horvat and colleagues
