tzu "comments"
My 2c, the slowing of the Gulf stream/N.Atlantic drift imho is caused by mixing with arctic waters which are inert and hold fast to the American mainland, that inertia is reflected in the size of the cold blob which is the G.S./Arctic water mixed to latitudinal equilibrium. The cold blob forces the G.S. south, it's relative inertia means it spends more time further south, travels further, gets warmer, more saline and arrives later. The loss of ice cover in Barentz has allowed more Atlantic water to force it's way into the Arctic over that shelf, in turn this has led to an [unconfirmed] steady increase in flow at depth though Fram. In turn this acts a little like a flywheel and if more water is leaving here more must flow in, according to 'current' circumstances. Generally this means increased inflow from the Atlantic either side of Svalbard or from the Pacific influenced by tides and barometric pressure, so extremely variable on any day. Every tidal cycle can add a little more power to the 'flywheel', and given the activity at Humbolt it seems something similar is evolving in Nares.