Understanding (some of) the Arctic Ocean: the Pacific inflow via the Bering Strait - change, implications and solving the 60-yr old riddle of what drives it

In the last 30 years, the Arctic has lost ~ 75% of its summer sea ice 
volume. This dramatic change is driven (it is thought) by a host of 
atmospheric and oceanic drivers. From the ocean side, both the 
Atlantic and Pacific oceans have influence on the Arctic - Atlantic 
waters entering through the Fram Strait and Barents Sea, and the fresher 
(and seasonally warmer) Pacific waters entering through the Bering 
Strait, a narrow (85km), shallow (50m) passage between the USA and 
Russia. Though this Pacific inflow (1Sv) is smaller than the net 
Atlantic inflow (~3-7Sv, depending on whom you ask), it is found to have 
a clear influence on the melt back of sea ice in the western Arctic. 
Year-round mooring observations in the Bering Strait show significant 
flow increase and warming since the 1990s, the only Arctic gateway to 
show significant trends. But what drives the Bering Strait flow in the 
first place? And what is causing the recent changes? And why (polar 
bears aside) should you care about a small strait on the other side of 
the world anyhow? Starting from an overview of key Arctic Oceanography 
and recent Arctic Change, we will move to addressing the 60-yr old 
riddle of what drives the Pacific Inflow to the Arctic Ocean.