Even scientists, it seems, have a hard time agreeing on how to define this phenomenon and what causes it.
What Does the Polar Vortex Have to do With Climate Change?
Published: February 4, 2019
Caitlin Saks: This is Antarctica. It was so cold that my snot froze. I just got home to the States, and it’s actually colder here than it was there, and I’m not even in Chicago.
So what on Earth is going on? I mean, literally, what the heck is our planet up to? If the planet’s supposed to be warming, why is it so cold?
This polar vortex has dominated the news headlines for the last week, but there’s a lot of confusion about what it actually is. To atmospheric scientists, the “polar vortex” refers to these high altitude stratospheric winds that are spinning really fast up near the North Pole. They trap a pool of super cold air over the Arctic. Sometimes, it splits in two. And that forces colder air south. But, this polar vortex has become well, polarizing.
It’s counterintuitive. If our planet is warming, then why is it so cold outside?
Jonathan Martin: The trend, even this year, with our cold this year, this winter is still among the warmest ever.
Jennifer Francis: It’s not negating global warming. There are really only two areas on the whole globe that are colder than normal right now. Everywhere else for the most part is warmer than normal.
Saks: Just because a particular weather event bucks the trend, doesn’t mean that the planet on average isn’t warming as a whole. And in fact, some scientists are starting to argue that this polar plunge is caused by climate change. Here’s the thinking: As the planet warms, the poles are warming a lot faster than the mid-latitudes, places like the US. The difference in temperature, or gradient between the North Pole and, say, the Midwest, is much less extreme than it used to be. That causes the polar vortex to weaken. And this makes our jet stream, which is at a lower altitude than the polar vortex, weaker and wavvier. And that drives our weather in the United States. But this is still a hotly debated hypothesis.
Martin: I think that the jump between saying that by slackening that temperature contrast from the midlatitudes to the pole, that doesn’t necessarily mean the jet stream is going to become wavvier.
Francis: It’s certainly played out this year just like the hypothesis says, and last year too.
David Holland: It looks like it’s global warming, but I don’t think anyone yet has enough data to nail that to the ground.
Saks: One thing is clear: the scientific community agrees that, despite the antarctic temperatures in the Midwest this week, the globe on average is still warming.
But if you are in one of those places that is experiencing record cold, try to stay warm. Check out some of the links in the description for more on the science of the arctic vortex, and how to survive the antarctic cold.
Hosted By: Caitlin Saks
Digital Producer: Emily Zendt
Production Assistance: Sukee Bennett, Allison Eck, Taylor White, Natalie DiDomenico, Lorena Lyon, Rishya Narayanan, Ana Aceves
Additional Footage: NASA, NOAA, ClimateReanalyzer.org, WKAR, Zachary Lawrence, Mat Rotman, Greg Kestin
© WGBH Educational Foundation 2019