Slowing of jet stream causing extreme winter weather

BBC : Recently the US Midwest has been suffering an unusually bitter winter, and the UK has been experiencing a rash of torrential storms. Such extreme weather events are the result of the slowing of the northern polar jet stream, according to Rutgers University’s Jennifer Francis, who presented her recent findings at the annual meeting of the American Association for the Advancement of Science. The jet stream is powered in part by the temperature differential between the Arctic and the midlatitudes. As the Arctic has been warming up, the temperature differential has been decreasing, which slows the air current flow. As a result, weather patterns can get stuck over certain areas for extended periods of time. Whether the recent extreme weather events are due to manmade climate change, however, remains to be determined, says Francis.