[vtsnowedin]

I would define "A blue ocean Arctic" as being able to sail directly from the Bering Strait to the pole then on past Longyearbyen to the Norwegian coast without having to smash through or detour around any ice.
On another note they have stopped providing the Modis pictures of the arctic but you can see similar from this link here.
https://worldview.earthdata.nasa.gov/?p ... lor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,MODIS_Aqua_Sea_Ice,Reference_Labels(hidden),Reference_Features(hidden),Coastlines&t=2018-09-21-T00%3A00%3A00Z&z=3&v=-5201920,-3608575.999999999,5201920,3608576.000000001&ab=off&as=2018-08-16T00%3A00%3A00Z&ae=2018-08-23T00%3A00%3A00Z&av=3&al=false

[Tanada]

"Surely, the definition of blue ocean is a percentage of winter ice cover lost, not total loss of ice"
So what would be the scientific definition of what percentage constitutes a Blue Ocean Event?

I believe the commonly accepted number is if the Arctic Ocean is 80% ice free aka less than 1 million square miles remain under ice cover at the end of the melt season it will be judged a 'blue ocean event'. By that standard 2012 came fairly close, we ended that years with about 1,350,000 mi^2.