Arctic Sea Level Falling?

HRH King Lerxst with a link to BBC News' report that "Arctic sea level has been falling by a little over 2mm a year — a movement that sets the region against the global trend of rising waters. ... It is well known that the world's oceans do not share a uniform height; but even so, the scientists are somewhat puzzled by their results."

Comments

Re:Isostatic rebound

[Vreejack]

I would hope they had taken isostatic rebound into account. Actually what puzzles me is how they measured sea level. Are they comparing it to the earth's geode? For those who never heard this before, the geode is an imaginary surface that represents where sea level would be if water were magically allowed to flow without viscosity underneath the earth's land mass. It is not a sphere or even a spheroid but follows the local gravity variations so that it actually rises underneath mountains and dips over marine trenches. The net force of gravity is always perpendicular to the surface of the geode, and when they report the height of Mount Everest it is with respect to the geode, not to the sea level a thousand miles away (which is lower).

So again, how are they measuring this? I can't think of any measurement that makes any sense. The ocean cannot be above the geode in one part of the world and below it in another _by definition_. At least not on average over a year.

Okay, here is my off-the-wall speculation: a new change in wind patterns has resulted in a net outflow of wind at the earth's surface around antarctica, effectively blowing the water away.