Curious Circles in Arctic Sea Ice
April 21, 2018
acquired April 14, 2018
NASA photograph by John Sonntag/Operation IceBridge.
NASAs Operation IceBridgethe airborne mission flown annually over both polar regionsis now in its tenth year making flights over the Arctic. Thats a lot of flight hours spent mapping the regions land ice and sea ice. But on April 14, 2018, IceBridge mission scientist John Sonntag spotted something he had never seen before.
Sonntag snapped this photograph from the window of the P-3 research plane while flying over the eastern Beaufort Sea. At the time, the aircrafts location was 69.71° North and 138.22° West, about 50 miles northwest of Canadas Mackenzie River Delta. We saw these sorta-circular features only for a few minutes today, Sonntag wrote from the field. I dont recall seeing this sort of thing elsewhere.
The features are more of a curiosity than anything else. The main purpose of the flight that day was to make observations of sea ice in an area that lacked coverage by the mission prior to 2013. Still, the image sparked a fair amount of intrigue, so we set out to see what we could learn. Thats not always easy based on a photograph or satellite image alone, so the following ideas are speculation.
Some aspects of the image are easy to explain. The sea ice here is clearly young ice growing within what was once a long, linear area of open water, or lead. The ice is likely thin, soft, and mushy and somewhat pliable, said Don Perovich, a sea ice geophysicist at Dartmouth College. This can be seen in the wave-like features in front of the middle amoeba.
More:
https://earthobservatory.nasa.gov/IOTD/view.php?id=92030&src=iotdrss