The unprecedented loss of polar sea ice may lead to ‘wild extremes’ in the UK and northern Europe. This heat and water vapour will affect the all-important jet stream – the west-to-east winds that are the boundary between cold Arctic and the warm mid-latitudes. Others researchers have already shown that the jet stream has been shifting northwards in recent years. Dr. Francis and colleagues have recently documented that the jet stream is also slowing down.
“The jet stream is clearly weaker,” said Francis. That means weather systems, be it rain or dry conditions, are slow to move on and last longer. Ultimately this can result in “blocking” events. These changes are happening much earlier than scientists thought. As the sea ice continues to decline, the jet stream will likely continue to slow more, and shift further north “bringing wild temperature swings and greater numbers of extreme events” in the future he said. “We’re in uncharted territory.”


[link to climatetoday.org]