Geophys. Res. Lett. doi:10.1029/2009GL041291 (2009)

Credit: © ISTOCKPHOTO / DAVID FREUND

The traditionally quiescent Arctic Ocean may soon become a more active environment owing to its diminishing sea ice. Floating ice impedes winds from transferring energy to the ocean, thereby minimizing waves both on and beneath the surface. Subsurface internal waves have an important role in mixing water between various depths, but this process occurs less in the Arctic than in other ocean basins.

In 2002 and 2003, University of Washington researchers Luc Rainville and Rebecca Woodgate moored instruments at 70 and 110 metres below the surface in the Chukchi Sea, north of the Bering Strait, an area typically iced over in winter and ice-free in summer. They found that storms with winds stronger than ten metres per second occurred all year, but they generated significant internal waves only in the absence of sea ice. The mixed layer of water resulting from those waves grew rapidly during summer.

As Arctic ice continues to decline year-round, the researchers anticipate increased mixing from internal waves. This could affect the success of phytoplankton blooms, the base of the Arctic food web. It may also affect exchanges of water between the Arctic and other oceans, with implications for climate connections to more southerly regions.