I wonder if the opposite could also happen. Think to the future when much more of the Arctic Ocean is ice free for longer periods in the summer and hence has accumulated much more heat. Toward fall, as the incident radiation on the surrounding land decreases, at some point, snow falls and doesn't melt. The land cools off very rapidly since only the top foot or so is involved. Now you have a very cool area surrounding the ocean, with the air above the land cooling off and falling. Over the ocean, by contrast, the heat accumulated in the summer is warming the air and putting much water vapor into the air. You have a positive AO from the surrounding land to the ocean and Coriolis starts this body of air rotating counter clockwise. It would seem to be a formula for some very strong cyclones in late summer and fall. Since in an anticlockwise rotating system, Coriolis is away-from-the-centre, if the ocean is spun counterclockwise by the storm, ice and fresh water should be pushed toward the exits from the Arctic ocean, making the surface water shallower and bringing the deep, salty, slightly warmer Atlantic water closer to the surface. The longer, higher waves from such storms will then be able to mix these layers more effectively, further pushing the Arctic toward an ice free condition.

At some point we should start to see large storms in the fall as the freezing of water and the giving out of latent heat keeps the air above the ocean relatively warm, relative to the land that is rapidly cooling off. Large Storms are generated by pressure differentials and in the tropics require water temperature above 25 degrees C. This is because over an open ocean, all the pressure differential is generated by the storm itself. In the Arctic, they require sufficiently high pressure over land relative to the pressure over the sea. I suspect the storm of 2012 was such a storm. It is likely that this year there is not enough open water to generate a mega storm.

This is probably simplistic but aren't we seeing a negative feed back amongst all the positive ones we have been focusing on. Thinner ice and a lot of cracking at the beginning of the melt season led to increased heat and water vapour entering the atmosphere (and of course, cooling the water/ice). This causes rising air and low pressure systems with clouds which shades the ice. Storms, when the ice is fairly wide spread can't have the effect on the sea as they do later in the season when they can create large waves and ice scattering. A storm a the height of the winter, for instance, hardly causes waves at all. Gaia is fighting back and while the over all trend will undoubtedly continue, we could see more of these odd years. At some point the ice at the end of the freezing season will be so thin that early storms will shatter it.

The rate of melting increased sharply following the storm of Aug6. Was this due to a mixing into the surface waters of the deep, warmer Atlantic water. a single meter of water which is one degree above the melting point of ice contains enough heat to melt 12.5mm of ice. There is more than enough heat in the artic water to melt all the ice many times over. Have any salinity measurements been made to see if such mixing did occur.

Could this melting be the first sign of a Walker cell developing between rising moist air over the open part of the Arctic ocean (and Atlantic, for that matter) and the descending katabatic (density) winds pouring down the slope of the Greenland Ice Sheet. The air that pours down Greenland has to come from somewhere.

So what happens when enough of the Arctic ocean is open water and becomes a giant solar collector such that it becomes an area of rising air instead of falling air. Presumably the Polar Hadley cell reverses and joins with the Ferrel cell (polar cell and polar jet stream disappears). The next jet stream down moves to about 45degrees North and takes up the job of pushing weather patterns around the globe. Heat is pulled by the northern most of the now two cell system toward the Arctic, melting what is left of the permafrost etc etc. A warm foehn wind blows over Greenland. http://mtkass.blogspot.co.nz/2008/07/arctic-melting-no-problem.html