Jim, you are quite right to call attention to this research -- what the Sikuliaq is doing out in the Beaufort is hugely important and has ominous implications for the ice pack future. Sikuliaq is an Inuit word for “young sea-ice that is safe to walk on”. Or not.
According to the PI: “While we hypothesized this might be happening, we have been genuinely thunderstruck by how incredibly strong the turbulence is below the surface. This heat is likely playing a substantial role in the melting of the ice that we can see all around us, growing thinner every day, and our job now is to distinguish summer melting from longer term change.
Near-inertial internal waves (NIW) can propagate downwards into stratified water and break hundreds of meters or more below the surface. Crucially, mixing in this depth range can tap into the large heat reservoir of Atlantic-origin water. Increased turbulent heat fluxes up from this water mass could significantly warm the upper ocean and accelerate ice loss."
Basically the Arctic Ocean is deep and warm enough melt out its thin skin of ice a thousand times over. The issue is that stratification by density effectively isolates this heat from the ice cover; a thin layer of stagnant cold water under the ice can't do much melting and diffusive processes are very slow.
With a full ice cover, there has been no mechanism by which the water could be mixed.
However these days, the Beaufort area can have a lot of open water in summer and with it longer fetches for wind, so bigger waves and more of these small underwater circulatory cells which lead to the turbulent mixing that the physical oceanographers on the Sikuliaq are measuring.
This is yet another effect to be added to swells breaking up the ice, Ekman transport, and advection of waters through the Bering Strait or North Atlantic. It seems every time we turn around there is another runaway feedback chewing at the ice that was never considered in the models.
Their effect is not to be found in "Intro to Oceanography" but rather in advanced and unfamiliar wave physics. Langmuir cells (slowly counter-rotating shallow vortices aligned with the wind) and turbulence (exceeding the Reynolds number of smooth flow) have been around a while but after that it really gets technical ... spice anomalies along isopycnal displacements, quasi-geostrophic turbulence theory, and far worse. I'll look into this further and see what has a more intuitive exposition.
Basics are well-explained at:
http://oceanworld.tamu.edu/resources/ocng_textbook/chapter08/chapter08_05.htm https://www.sikuliaq.alaska.edu/track/https://en.wikipedia.org/wiki/Turbulencehttps://en.wikipedia.org/wiki/Langmuir_circulationSee also:
http://www-pord.ucsd.edu/~jen/research.htmlhttp://scrippsscholars.ucsd.edu/awaterhouse/content/global-patterns-diapycnal-mixing-measurements-turbulent-dissipation-rate
