New Scientist - Rapidly Warming Arctic May Power Extreme Heatwaves & Droughts In N. Hemisphere

[hatrack]

It seems our weather is getting slower – and hotter. Arctic warming appears to be aggravating summer heatwaves across Europe and North America, by putting the brakes on atmospheric circulation in mid-latitudes.

The team that uncovered this Arctic effect says it caused the Russian heatwave of 2010, which lasted six weeks, killing crops and causing massive forest fires; the west European scorcher of 2003 that killed an estimated 70,000 people; and possibly the record US heatwave of 2012, which decimated corn crops.

Dim Coumou and colleagues at the Potsdam Institute for Climate Impact Research in Germany studied atmospheric circulation in the northern hemisphere from 1979 to 2013. They found longer and more frequent hot spells in mid-latitudes that, they say, are likely to have been triggered by a reduction in the temperature difference between the Arctic, which is warming quickly, and mid-latitudes, where average warming is slower.

The Arctic has in fact warmed twice as fast as the rest of the globe, because of the melting of the ice replaces a reflective surface with dark ocean that absorbs much more solar energy. Climatologists believe that this temperature difference drives the general west-to-east movement of mid-latitude weather systems, such as the depressions that bring storms and the high-pressure systems that bring hot dry weather in summer and intense cold in winter. A smaller temperature difference slows these systems down, so their associated weather persists for longer.

EDIT

http://www.newscientist.com/article/dn27150-warming-arctic-blamed-for-worsening-summer-heatwaves.html#.VSNOoeHth3M

[WheelWalker]

1. Kick

[Bigmack]

2. And the GREAT irony of this is that

with more fresh water about in the No. Atlantic, the further south the thermohaline current will sink down, and the COOLER Europe will be!!!!! Ms. Bigmack