Recent Slowdown of AMOC Possibly Linked to Greenland Melt

[jai mitchell]

http://www.vox.com/2015/3/23/8277345/atlantic-overturning-circulation

Now, a new study in Nature Climate Change argues the Atlantic overturning already seems to be weakening dramatically. The researchers, led by Stefan Rahmstorf of the Potsdam Institute for Climate Research, created a novel reconstruction of the AMOC's behavior going back centuries. They conclude the system hasn't been this weak in 1,100 years, perhaps due to an influx of freshwater from Greenland's melting ice sheet. (This contrasts with previous research suggesting the AMOC was still fluctuating in natural cycles.)

So how worrisome is this? For now, most scientists remain confident we won't see a sudden shutdown anytime soon. Mainstream climate models have long predicted that the AMOC would eventually weaken as the Earth warms, but those models don't forecast huge, abrupt changes this century.

In their study, Rahmstorf and his co-authors point out that Greenland has been melting significantly in the past few decades. That influx of cool freshwater can reduce the surface density of ocean water in the North Atlantic and, in turn, weaken the AMOC. If that's true, then the AMOC is already slowing down due to climate change, not fluctuating naturally:

[Neven]

Thanks for opening this topic, jai, but another one has been opened already dealing with this subject.