The Arctic Ocean is generally considered a remarkably quiet ocean, with very little mixing, because a cover of sea ice prevents wind from driving the formation of internal waves. To study this effect and investigate how melting sea ice might affect ocean mixing in the Arctic, Rainville and Woodgate analyze data from moorings in the northern Chukchi Sea.

They find that when the ocean was mostly covered with ice, even strong winds did not generate much response in it. On the other hand, during the summers when less sea ice was present, wind generated large internal oscillations and increased turbulence.

The extent of Arctic sea ice in the summer has been declining significantly in recent years, likely resulting in increased internal wave generation, the authors note. Because internal waves bring deeper waters closer to the surface, the results have important implications for Arctic Ocean ecosystems and ocean dynamics.

The research is published in Geophysical Research Letters. Authors include Luc Rainville and Rebecca A. Woodgate: Applied Physics Laboratory, University of Washington, Seattle, Washington, USA.