字幕列表 影片播放 列印英文字幕 The polar vortex is upon us! Sinners turn up your local heat sources, prepare for the oncoming snowpocalypse! Where did this thing come from? Hey cold ones, this is DNews, I'm Trace. If you'd asked me about the POLAR VORTEX in 2013, I'd have assumed it was the bad guy in some new cheesy superhero show. In 2014, when a blizzard and cold system struck for some reason it got a new, catchy name: the Polar Vortex. It was so popular, Bloomberg joked it was in the “uncontested lead” for “buzzword of 2014” This “new” meteorological term was everywhere! Except that, the polar vortex as you know it is a lie. It's not new. What the media dubbed 'the polar vortex' is really just the arctic or polar jet stream, also known as one of the “Westerlies,” or circumpolar vortex; we've known about it for decades. Though, now that we have a cute term for it, we're hearing it more! You're not imagining things. I'm about to say something confusing, but trust me on this. The polar vortex is spilling out of the top of the planet... scientists think… because of global warming. Yes, it's getting colder because it's getting warmer. It's called the “warm Arctic-cold continents” pattern. Atmospheric science is complicated. But, again, the polar vortex isn't a new thing. In January 1985, we hit record cold temperatures, negative 34 degrees in North Carolina, paired with blizzards in the Northeast -- even Florida was affected! Then, in December of 1989, another very cold huge blizzard hit, dropping record snow and dipping the temperature to zero in North Carolina . They didn't call it the polar vortex, instead referring to “Cross-polar flow” or the polar jet stream was pushing this cold air onto us. Blizzards and polar air hit in 1977, '78, '82 '85, '89. In '93 they called it “the storm of the century!” '96, 2008 you get it. In 2014, a bit of this jet stream shifted, allowing polar air to “slosh out of the bowl” on top of the planet. Jet streams and low-pressure systems were hitting the U.S. almost every year -- all thanks to this 'polar vortex.' OK. So. What is this thing… Here is the top of the Earth, just chilling. That is a sweet Earth you might say. And that is the circumpolar vortex. A.k.a. 'The polar vortex.” As the National Oceanic and Atmospheric Administration puts it: the jet stream is “wobbling” because the circumpolar vortex is basically a low-pressure cold system that is held in place, by the west-to-east moving jet stream. But in recent years, the oval-shaped jet stream on top of our planet is breaking down. It's been on this trend for decades. And, a study in October 2016's Nature explores how climate change is a possible cause. The warming of our planet is weakening the polar jet stream, reducing sea ice and causing this “sloshing of cold air.” That cold air causes cold temperatures, and crazy winter weather. On top of that, as the jet stream changes, the polar vortex is shifting from North America to Europe and Asia. You can secretly cheer, but you'd be wrong to do so. A weaker polar jet stream means more cold air down away from the poles, not less -- it might mean longer winters, with the polar vortex showing up in March. This stuff is really complicated. And, to further complicate things. There are two polar vortices! One circumpolar vortex floats in the stratosphere, which rests 50 kilometers above the Earth, and another circumpolar vortex sits in troposphere (between 5 and 20 kilometers). So what you're feeling on your frozen face, is just the influence of these polar winds, not necessarily the polar winds themselves. Whew. This could get chilly. Oh, and P.S. there are polar vortices at the bottom of the planet, too. To be honest, as much as we humans love going to the beach, we can only hope that the cold air stays cold. Because if that sea ice melts, we're screwed. Global warming. Not only is it hotter, but it's colder too. Why doesn't winter disprove global warming? Don't worry. Got the answer to that for you right here. I remember cold, probably why I have a MOP of hair in that vid. How do you feel about the media blowing up these winter norms? Tell us about it down in the comments, make sure you come back here everyday for more DNews and thanks for watching!