Dominoes fall: Vanishing Arctic ice shifts jet stream, which melts Greenland glaciers [View all]

[jpak]

https://www.washingtonpost.com/news/energy-environment/wp/2016/05/02/dominoes-fall-vanishing-arctic-ice-shifts-jet-stream-melts-greenland-glaciers/

Investigating the factors affecting ice melt in Greenland — one of the most rapidly changing places on Earth — is a major priority for climate scientists. And new research is revealing that there are a more complex set of variables affecting the ice sheet than experts had imagined. A recent set of scientific papers have proposed a critical connection between sharp declines in Arctic sea ice and changes in the atmosphere, which they say are not only affecting ice melt in Greenland, but also weather patterns all over the North Atlantic.

The new studies center on an atmospheric phenomenon known as “blocking” — this is when high pressure systems remain stationary in one place for long periods of time (days or even weeks), causing weather conditions to stay relatively stable for as long as the block remains in place. They can occur when there’s a change or disturbance in the jet stream, causing the flow of air in the atmosphere to form a kind of eddy, said Jennifer Francis, a research professor and climate expert at Rutgers University.

Blocking events over Greenland are particularly interesting to climate scientists because of their potential to drive temperatures up and increase melting on the ice sheet.

“When they do happen, and they kind of set up in just the right spot, they bring a lot of warm, moist air from the North Atlantic up over Greenland, and that helps contribute to increased cloudiness and warming of the surface,” Francis said. “When that happens, especially in the summer, we tend to see these melt events occur.”

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