The Coolest Meteorological Term You'll Learn This Week

Two tropical cyclones orbiting around each other in the northwestern Pacific Ocean on July 25, 2017.
Two tropical cyclones orbiting around each other in the northwestern Pacific Ocean on July 25, 2017.
RAMMB/CIRA

What happens when two hurricanes start to invade each other's personal space? It's easy to picture the two hurricanes merging into one megastorm that tears across the ocean with twice the fury of a normal storm, but what really happens is less dramatic (although it is a beautiful sight to spy on with satellites). Two cyclones that get too close to one another start to feel the pull of a force called the Fujiwhara Effect, a term that's all the rage in weather news these days.

The Fujiwhara Effect occurs when two cyclones track close enough to each other that the storms begin orbiting around one another. The counterclockwise winds spiraling around each cyclone force them to participate in what amounts to the world's largest game of Ring Around the Rosie. The effect is named after Sakuhai Fujiwhara, a meteorologist who studied this phenomenon back in the early 1900s.

The extent to which storms are affected by the Fujiwhara Effect depends on the strength and size of each system. The effect will be more pronounced in storms of equal size and strength; when a large and small storm get too close, the bigger storm takes over and sometimes even absorbs its lesser counterpart. The effect can have a major impact on track forecasts for each cyclone. The future of a storm completely depends on its new track and the environment it suddenly finds itself swirling into once the storms break up and go their separate ways.

We've seen some pretty incredible examples of the Fujiwhara Effect over the years. Hurricane Sandy's unusual track was in large part the result of the Fujiwhara Effect; the hurricane was pulled west into New Jersey by a low-pressure system over the southeastern United States. The process is especially common in the northwestern Pacific Ocean, where typhoons fire up in rapid succession during the warmer months. We saw a great example of the effect just this summer when two tropical cyclones interacted with each other a few thousand miles off the coast of Japan.

Weather Channel meteorologist Stu Ostro pulled a fantastic animated loop of two tropical cyclones named Noru and Kulap swirling around each other at the end of July 2017 a few thousand miles off the coast of Japan.

Typhoon Noru was a small but powerful storm that formed at about the same latitude as Kulap, a larger but much weaker storm off to Noru's east. While both storms were moving west in the general direction of Japan, Kulap moved much faster than Noru and eventually caught up with the latter storm. The Fujiwhara Effect caused Typhoon Noru to stop dead in its tracks, completely reverse its course and eventually perform a giant loop over the ocean. Typhoon Noru quickly strengthened and became the dominant cyclone; the storm absorbed Kulap and went on to become a super typhoon with maximum winds equivalent to a category 5 hurricane.

Amazon's Under-the-Radar Coupon Page Features Deals on Home Goods, Electronics, and Groceries

Stock Catalog, Flickr // CC BY 2.0
Stock Catalog, Flickr // CC BY 2.0

This article contains affiliate links to products selected by our editors. Mental Floss may receive a commission for purchases made through these links.

Now that Prime Day is over, and with Black Friday and Cyber Monday still a few weeks away, online deals may seem harder to come by. And while it can be a hassle to scour the internet for promo codes, buy-one-get-one deals, and flash sales, Amazon actually has an extensive coupon page you might not know about that features deals to look through every day.

As pointed out by People, the coupon page breaks deals down by categories, like electronics, home & kitchen, and groceries (the coupons even work with SNAP benefits). Since most of the deals revolve around the essentials, it's easy to stock up on items like Cottonelle toilet paper, Tide Pods, Cascade dishwasher detergent, and a 50 pack of surgical masks whenever you're running low.

But the low prices don't just stop at necessities. If you’re looking for the best deal on headphones, all you have to do is go to the electronics coupon page and it will bring up a deal on these COWIN E7 PRO noise-canceling headphones, which are now $80, thanks to a $10 coupon you could have missed.

Alternatively, if you are looking for deals on specific brands, you can search for their coupons from the page. So if you've had your eye on the Homall S-Racer gaming chair, you’ll find there's currently a coupon that saves you 5 percent, thanks to a simple search.

To discover all the deals you have been missing out on, head over to the Amazon Coupons page.

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The Northern Lights Storms Are Getting Names—and You Can Offer Up Your Suggestions

A nameless northern lights show in Ylläs, Finland.
A nameless northern lights show in Ylläs, Finland.
Heikki Holstila, Flickr // CC BY-ND 2.0

While all northern lights are spectacular, they’re not all spectacular in the same way. Aurora borealis, or “northern dawn,” occurs when electrons in the magnetic field surrounding Earth transfer energy to oxygen and nitrogen molecules in the atmosphere. The molecules then emit the excess energy as light particles, which create scintillating displays whose colors and shapes depend on many known and unknown factors [PDF]—type of molecule, amount of energy transferred, location in the magnetosphere, etc.

Though the “storms” are extremely distinct from each other, they haven’t been named in the past the way hurricanes and other storms are christened. That’s now changing, courtesy of a tourism organization called Visit Arctic Europe. As Travel + Leisure reports, the organization will now christen the strongest storms with Nordic names to make it easier to keep track of them.

“There are so many northern lights visible in Arctic Europe from autumn to early spring that we started giving them names the same way other storms are named. This way, they get their own identities and it’s easier to communicate about them,” Visit Arctic Europe’s program director Rauno Posio explained in a statement.

Scientists will be able to reference the names in their studies, much like they do with hurricanes. And if you’re a tourist hoping to check out other people’s footage of the specific sky show you just witnessed, searching by name on social media will likely turn up better results than a broad “#auroraborealis.”

Visit Arctic Europe has already given names to recent northern lights storms, including Freya, after the Norse goddess of love, beauty, and fertility, and Sampo, after “the miracle machine and magic mill in the Finnish national epic poem, ‘Kalevala.’” A few other monikers pay tribute to some of the organization’s resident “aurora hunters.”

But you don’t have to be a goddess or an aurora hunter in order to get in on the action. Anybody can submit a name (along with an optional explanation for your suggestion) through the “Naming Auroras” page here. It’s probably safe to assume that submissions related to Nordic history or culture have a better chance of being chosen, but there’s technically nothing to stop you from asking Visit Arctic Europe to name a northern lights show after your dog.

[h/t Travel + Leisure]