Last winter, after parts of the eastern United States, including NYC, suffered an extended cold snap that broke all-time records in some places, the media latched onto the term: “polar vortex.” It sounded movie-title-ish, like a sequel to The Day After Tomorrow, and so was bound to catch on. And it did.
This year we’re at it again, touting headlines like “The Polar Vortex is Coming to Ruin Your Week.” But climate experts say the December-like chill we’re poised to experience later this week is not the polar vortex moving over the United States. First off, the polar vortex is a fixed natural phenomenon, a region containing cold air that has always existed at the poles in both the Northern and Southern hemispheres. And if the entire entity actually moves over the U.S., that could spell big planetary problems. In the Northern Hemisphere, the cold air is called Arctic air.
A polar vortex consists of what Mark Serreze, a meteorologist at the National Snow and Ice Data Center, calls “meanders in its flow” — akin to spinning eddies of air. During last winter’s cold spell, one of these meanders dipped southward, causing an outbreak of cold air.
— Susie Martin Wx (@smartinWX) November 10, 2014
This southward dip of some of these “meanders” is what New Yorkers should brace for as the Arctic air, and its unseasonably cold temperatures, makes it way steadily to New York and other states in the eastern and central U.S. But it’s not a polar vortex. And meteorologists of the world are kindly asking that we stop using that term.
Some are comfortable with using the term “polar-vortex-influenced cold air” instead. The air is “cold because it moved from the pole to lower latitudes fairly quickly,” says Adam Sobel, an atmospheric scientist and Columbia University professor. Sobel, who authored Storm Surge, a book on Hurricane Sandy and climate change, says there are different reasons for the meanders.
This week’s case “appears to be influenced in part by former typhoon Nuri, now a very powerful winter storm approaching Alaska,” he told the Voice.
“To some extent every winter storm is connected to the polar vortex in at least an indirect way,” he said. “That is one of the reasons the term [polar vortex] is not very helpful — it seems to be a new word that people associate with last winter’s very extreme cold, but really one could relate almost any cold snap to the polar vortex in some way if one were inclined toward hype.”
While the circumstances behind last winter and this week’s freezing temperatures are similar, it will not get as cold on the East Coast in particular, as it is too early in the season. Temperatures in NYC are likely to remain in the 30s towards the end of the week.
According to Serreze, this week’s wintry spell will manifest in the “passage of a strong cold front,” i.e., the leading edge of an advancing mass of cold air, which typically moves in such a way that colder air replaces warmer.
Sobel says he and many of his colleagues wish the media would drop the term polar vortex altogether, as it seems to confound people as much as it educates them. “However, I’m afraid it may be too late to put that cat back in the bag,” he said.
On the other hand, Serreze, who specializes in Arctic climate and the global implications of climate warming, pointed out the danger in labeling every push of cold air the “polar vortex.” “In using sensationalism to sell a story, the science becomes distorted and people can get very confused.
“There will always be interesting weather events, and many will be newsworthy, but when the science gets lost in hype, we all lose,” he said.