Anne,
The area of open water that the wind blows across is known as the fetch. The larger the fetch, then more energy gets stored in the movement of the water. This energy comes from slowing the wind down, so an ice covered Arctic would have higher average wind speeds than an open ocean Arctic.
Initially the wind across the surface of water will produce small ripples, this roughens the surface and so small waves appear. These waves provide a rougher surface that better grip the wind, and so impart more energy into the water. The longer the wind blows, and across greater distances, the more energy is imparted to the water - and it can be huge amounts of enery. Storm waves can have many Megawatts per meter of wave front.
Short wavelength waves can have a massive pounding effect around the edges of the ice pack, the energy being dissapated by damping effect of breaking and grinding the ice against itself.
The trouble is that waves can only reach a certain hight before they become unstable, a function of water depth, wind speed and other factors. Adding more wind energy into the waves will not produce bigger waves but instead will start to induce long term waves known as swells. Once the fetch gets into a distance of hundreds of miles or more then these swells will travel pretty much as far as there is water. Thousands of miles in some cases - swells from storms off Argentina can be measured off the coast of the UK and Ireland and even Iceland.
Once the open ocean of the Arctic has a large enough fetch to produce a good swell, then that wave will travel for hundreds of miles into the ice-pack, fracturing as it goes. Moving the ice up and down has almost no dampig effect, it's only the fracturing and small amount of grinding that that induces that will use up the waves energy. The huge amount of eneregy and the long wavelength of these swells means that the energy will be disappated across a very large area of ice.
The waves also have an effect deeper down. The effect of a wave can be mesured to a depth of twice it's wavelength. The water within any wave doesn't move along with the wave, but simple goes around in a vertical circular motion. This has a mixing effect on deeper waters and so helps break up the thermocline - layers of different temperature water.
An ice free Arctic is a totally different place to an ice covered one. The ice provides such a calming influence to the whole basin, and not just it's surface.
