Satellite observations dating back to 1995 indicate that strong winds and an ocean current known as the Beaufort Gyre have made the sea surface bulge upward, especially over the past decade when it rose by 6 inches.
Trapped in this vortex is a mass of freshwater from unusually high river and stream runoff originating on the Eurasian (Russian) side of the Arctic basin.
Of concern is what could happen if the winds were to reverse, which happened between the mid-1980s and mid-1990s.
That could allow the dome to collapse and spill out to the edges of the Arctic and beyond.
If the freshwater were to enter the North Atlantic in large volumes, scientists fear it could disturb a current coming from the Gulf Stream, which keeps Europe much warmer than its high-latitude position would normally allow.
Some researchers believe the effects on climate from such a reversal of the Arctic winds could be much greater now due to recent global warming.