Scientists suspect this may be making the jet stream slow down and meander, rather than speeding around the planet as it usually does. That's because of the jet stream-a narrow band of strong winds high up in the atmosphere that pushes weather systems along. The jet stream is powered by the temperature difference between the Arctic and the mid-latitudes, and this difference is shrinking as the Arctic warms. In some places, winter temperatures are as much as 7☏, or almost 4☌ warmer than they were just 50 years ago.Īrctic warming affects weather patterns in the mid-latitudes, where most people live. The Arctic has warmed about twice as fast as the rest of the world. A warmer Arctic may be causing wintertime weather to get "stuck" more often, with cold air diving south and warm air heading north. The rapid rise in Arctic temperatures relative to the slower warming elsewhere may be leading to a more meandering jet stream. The Arctic is warming twice to three times as fast as the global rate due to the unique features in the Arctic climate system-a phenomenon known as Arctic amplification. We may see more unusual polar vortex behavior in the future. Thee link between a slow, wavy jet-stream and extreme U.S. When the jet stream gets wavy, cold Arctic air “falls” down into lower latitudes - sometimes into the U.S. But there is mounting evidence that the rapid warming of the Arctic is making for a more wavy jet stream, with waves that move more slowly across the globe. The extremely cold air above the Arctic in winter is typically corralled by the polar vortex jet stream. There is significant evidence that this particular type of cold snap, known as an extension of the polar vortex, may be a symptom of climate change. And just because the globe is warming overall doesn't mean cold temperatures have been completely eradicated. Cold snaps in the Upper Midwest have become much less frequent. The recent National Climate Assessment explained how warmer winters are allowing pests to kill more trees, which leads to more wildfires are already decreasing snowpack and costing the winter recreation industry money and allowed for the northward spread of Lyme disease, among others.īut as NOAA has explained, there’s actually good reason to expect heavier snow storms in some locations, even as we experience less overall cold. We’re seeing a lot more record hot weather than record cold, by about a 2 to 1 margin. The past four years have been the hottest on record for the globe, and there hasn’t been a cooler-than-average year in three decades. The long-term warming trend is clear and undeniable. It means more warm weather than cold, and that’s what we’ve seen. īackground information Climate change doesn’t mean no more cold weather anywhere ever. Global warming has now gone beyond adding energy to the thermodynamic dimension of our climate and is now the patterns of atmospheric circulation, including the jet stream.Ītmospheric blocking due to anomalous, persistent, meandering of the jet stream often causes weather extremes in the midlatitudes. ĭisruption via Arctic warming affects weather patterns in the mid-latitudes, e.g. The Arctic is warming twice to three times as fast as the global rate due to the unique feedbacks in the Arctic climate system-a phenomenon known as Arctic amplification. Climate change disrupts regional weather patterns and can bring cold further south while warm air can travel further north.
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