Warmer Arctic, Weaker Jet Stream Make Long-Term Severe Winter Cycle Possible For N. Hemisphere

[hatrack]

EDIT

According to Jennifer Francis, a climate expert at Rutgers University, the Arctic air has warmed in recent years as a result of melting polar ice caps, meaning there is now less of a difference in temperatures when it hits air from lower latitudes.

"The jet stream is a very fast moving river of air over our head," she said Saturday at a meeting of the American Association for the Advancement of Science. "But over the past two decades the jet stream has weakened. This is something we can measure," she said.

As a result, instead of circling the earth in the far north, the jet stream has begun to meander, like a river heading off course. This has brought chilly Arctic weather further south than normal, and warmer temperatures up north. Perhaps most disturbingly, it remains in place for longer periods of time.

The United States is currently enduring an especially bitter winter, with the midwestern and southern US states experiencing unusually low temperatures. In contrast, far northern regions like Alaska are going through an unusually warm winter this year. This suggests "that weather patterns are changing," Francis said. "We can expect more of the same and we can expect it to happen more frequently."

EDIT

http://www.google.com/hostednews/afp/article/ALeqM5gRATyEqJNYEkuLb_12r2gh86GqrQ?docId=0e8aa38a-f890-4f3a-8068-bad3b6a90be6

[freshwest]

1. Good explanation. Still won't affect the deniers. 'But it's cold!' n/t