Will 2017 be a Blue Ocean Event year? We're watching systemic causality, in which multiple effects interact and feedback loops occur.
Is it cause or effect?
Water vapor transport/sea ice loss/warming oceans/warming polar atmosphere/wavier northern hemisphere atmospheric circulation are coupled non-linear processes. It may be entertaining to argue chicken vs egg but it's pretty pointless. Linear thinking gets us into trouble in a nonlinear world.
I fear that this insanely warm Arctic winter is the beginning of a new atmospheric regime for the northern hemisphere that will be coupled with the disappearance of Arctic sea ice in late summer. Perhaps this won't be the year of an ice free September but this is the kind of winter I would expect to see before an ice free September. There's been not only extraordinarily warm weather and high ice export out of the Fram and Nares straits. Moreover there's been greater than normal warm water import from the Atlantic over the past year. [emphasis mine]
This is a 4 standard deviation event in the stratosphere causing extreme upper altitude warming. I have not seen any characterization of causality yet. Very high geopotential height and temperature anomalies at the 10 hPa altitude level. [emphasis mine]
Temperatures are expected to rise above freezing over the next few days in the Arctic Ocean north of Svalbard. See the pink excursion marked with an arrow. Above freezing air temperature north of the Arctic Circle in deep Winter is unusual.
image source (arrow mine) I had to chop the title "Stratospheric Monitoring" in half to fit both parts of the chart here.