What Is the Jet Stream, and How Does It Work?

Trapped between two big high-pressure systems, Hurricane Harvey has stalled over Houston, to devastating effect. As the Washington Post notes, if the jet stream were to dip far enough south, it could push Harvey out. Unfortunately, that's not in the forecast.

But what is the jet stream?

A jet stream is a swift current of air that encircles the globe right around the cruising altitude of a commercial airplane. It's easy to forget that there are vast rivers of wind whooshing just a few miles above our heads at speeds that could put most hurricanes and tornadoes to shame, but jet streams affect us every day without our realizing it. These speedy winds drive or influence just about every weather system that we have the pleasure—or misfortune—of experiencing. Planes even use it to cut down on fuel consumption and travel times.

There are usually two jet streams in each hemisphere, the polar jet and the subtropical jet. When we talk about "the jet stream," we're generally talking about the stronger polar jet stream, because most of our weather is driven by it. It's typically found at the same latitude as the U.S.-Canadian border.

We're often guilty of oversimplifying weather events by blaming everything on a clash between warm air and cold air, but temperature gradients really do have an enormous impact on where the jet stream forms and how strong it is. Jet streams form as air in the upper atmosphere moves from south to north and gets deflected to the east by the Coriolis effect. The jet stream will get stronger if the warmer temperatures are to the south and the colder the air is to the north. This is why the jet stream strengthens and dips over the United States during the winter, while it weakens and retreats north into Canada during the heat of the summer.

The jet stream drives our weather through phenomena called troughing, ridging, and jet streaks. Troughs and ridges are curves in the jet stream that are analogous to low pressure (troughs) and high pressure (ridges). In the northern hemisphere, a trough is a southward dip in the jet stream and a ridge is a northward hump in the wind current. You can expect active weather ahead of a trough and quiet weather beneath a ridge.

A jet streak is an area of much faster winds within the jet stream itself. Winds in a jet stream routinely climb above 100 mph, but the wind in a jet streak can clock speeds of more than 200 mph in a boisterous weather pattern. Troughs and jet streaks often team up to create low-pressure systems at the surface, and that's what gives birth to most of our interesting weather. Winds don't flow in a straight line as they twist around a trough or speed in and out of jet streaks. Air collides going into a trough and diverges as it leaves a trough. The same goes for jet streaks.

The process of winds exiting a trough or a jet streak, known as divergence, creates a void in the upper atmosphere. Nature hates imbalance and will do just about anything to balance something that's out of whack. When winds diverge coming out of certain parts of the jet stream, air will rush up from lower altitudes to fill the void. This upward rush of air from the surface leaves lower air pressure at the surface, creating a low-pressure system that can trigger all sorts of nasty weather.

The jet stream is also one of those weather features that could feel the effects of climate change over the coming decades and centuries. Since these wind currents rely on sharp temperature gradients in order to form, a warmer atmosphere will lessen the temperature difference between north and south and possibly create weaker jet streams. A weaker jet stream could act more erratically, creating longer stretches of quiet weather—but also more frequent weather extremes.

Divers Swim With What Could Be the Biggest Great White Shark Ever Filmed

iStock.com/RamonCarretero
iStock.com/RamonCarretero

New pictures and video taken by divers show what could possibly be the largest great white shark ever caught on camera, CNN Travel reports.

Deep Blue, a 50-plus-year-old great white first documented 20 years ago, was spotted off the coast of Hawaii recently in a rare close encounter. Divers were filming tiger sharks feeding on a sperm whale carcass south of Oahu when Deep Blue swam up and began scratching herself on their boat. They accompanied the shark in the water for the rest of the day, even getting close enough to touch her at times.


View this post on Instagram

A post shared by Ocean Ramsey #OceanRamsey (@oceanramsey) on

"She swam away escorted by two rough-toothed dolphins who danced around her over to one of my [...] shark research vessels and proceeded to use it as a scratching post, passing up feeding for another need," Ocean Ramsey, one of the divers, wrote in an Instagram post.


View this post on Instagram

A post shared by Ocean Ramsey #OceanRamsey (@oceanramsey) on

Deep Blue is roughly 20 feet long and weighs an estimated 2 tons—likely making her one of the largest great whites alive. (The record for biggest great white shark ever is often disputed, with some outlets listing an alleged 37-foot shark recorded in the 1930s as the record-holder.)

Deep Blue looks especially wide in these photos, leading some to suspect she's pregnant. Swimming so close to great whites is always dangerous, especially when they're feeding, but older, pregnant females tend to be more docile.

Though great white sharks are the largest predatory sharks in the ocean, sharks of Deep Blue's size are seldom seen, and they're filmed alive even less often, making this a remarkable occurrence.

[h/t CNN Travel]

The Psychology Behind Kids' L.O.L. Surprise! Doll Obsession

Jack Taylor, Getty Images
Jack Taylor, Getty Images

Isaac Larian, the founder and CEO of toymaker MGA Entertainment, is an insomniac. Fortunately for him, that inability to sleep forced him to get up out of bed one night—a move that ended up being worth $4 billion.

Larian’s company is the architect of L.O.L. Surprise!, a line of dolls with a clever conceit. The product, which retails for about $10 to $20, is encased in a ball-shaped plastic shell and buried under layers of packaging, forcing children to tear through a gauntlet of wrapping before they’re able to see it. The inspiration came on that highly profitable sleepless night, which Larian spent watching unboxing videos on YouTube. It resulted in the first toy made for a generation wired for delayed gratification.

The dolls first went on sale in test markets at select Target stores in late 2016. MGA shipped out 500,000 of them, all of which sold out within two months. A Cabbage Patch Kid-esque frenzy came the following year. By late 2018, L.O.L. Surprise! (the acronym stands for the fancifully redundant Little Outrageous Little) had moved 800 million units, accounted for seven of the top 10 toys sold in the U.S., and was named Toy of the Year by the Toy Association. Videos of kids and adults unboxing them garner millions of views on YouTube, which is precisely where Larian knew his marketing would be most effective.

A woman holds a L.O.L. Surprise doll and packaging in her hand
Cindy Ord, Getty Images for MGA Entertainment

The dolls themselves are nothing revolutionary. Once freed from their plastic prisons, they stare at their owner with doe-eyed expressions. Some “tinkle,” while others change color in water. They can be dressed in accessories found in the balls or paired with tiny pets (which also must be "unboxed"). Larger bundles, like last year’s $89.99 L.O.L. Bigger Surprise! capsule, feature a plethora of items, each individually wrapped. It took a writer from The New York Times 59 minutes to uncover everything inside.

This methodical excavation is what makes L.O.L. Surprise! so appealing to its pint-sized target audience. Though MGA was advised that kids wouldn’t want to buy something they couldn’t see, Larian and his executives had an instinctual understanding of what child development experts already knew: Kids like looking forward to things.

Dr. Rachel Barr, director of Georgetown University’s Early Learning Project, told The Atlantic that unboxing videos tickle the part of a child’s brain that enjoys anticipation. By age 4 or 5, they have a concept of “the future,” or events that will unfold somewhere other than the present. However, Barr said, they’re also wary of being scared by an unforeseen outcome. In an unboxing video, they know the payoff will be positive and not, say, a live tarantula.

L.O.L. Surprise! is engineered to prolong that anticipatory joy, with kids peeling away wrapping like an onion for up to 20 minutes at a time. The effect is not entirely novel—baseball card collectors have been buying and unwrapping card packs without knowing exactly what’s inside for decades—but paired with social media, MGA was able to strike oil. The dolls now have 350 licensees making everything from bed sheets to apparel. Collectors—or their parents—can buy a $199.99 doll house. So-called “boy toys” are now lurking inside the wrappers, with one, the mohawk-sporting Punk Boi, causing a mild stir for being what MGA calls “anatomically correct.” His tiny plastic genital area facilitates a peeing function.

Whether L.O.L. Surprise! bucks conventional toy trends and continues its popularity beyond a handful of holiday seasons remains to be seen. Already, MGA is pushing alternative products like Poopsie Slime Surprise, a unicorn that can be fed glitter and poops a viscous green slime. An official unboxing video has been viewed 4.2 million times and counting.

SECTIONS

arrow
LIVE SMARTER