What Is El Niño, and Why Does It Have Such a Big Impact?

Sea surface temperature anomalies, in °C, January 24–31, 2016

A snowstorm in the Midwest this week has its roots in a weather pattern influenced by El Niño—a disturbance that dropped several inches of rain in California, traversed the Rocky Mountains, and spun-up a formidable blizzard that threatens to produce up to a foot of snow across the central United States. El Niño has taken on an almost legendary quality in the United States, entering the collective mind of the public in the late 1990s as an epic weather pattern that drenches California in an unending deluge of tropical moisture.

An El Niño is the abnormal warming of sea surface temperatures in the eastern equatorial Pacific Ocean. The event occurs when winds over the Pacific Ocean near the equator slow down or reverse direction, allowing unusually warm water to accumulate around the eastern part of the equatorial Pacific. When sea surface temperatures in this portion of the Pacific climb 0.5°C above average for seven consecutive months, it’s officially considered an El Niño. Now, an upward shift of one-half of one degree doesn’t sound like much—it’s not!—but, in a similar way to a fever in the human body, it doesn’t take much abnormal heat to make a huge impact both on the ocean and the atmosphere above it.

How can warm water in the Pacific Ocean affect the weather thousands of miles away? Everything is connected. One of the most heavily advertised effects of El Niño is that it can squash the Atlantic hurricane season as the warm water triggers thunderstorms in the eastern Pacific, causing strong upper-level winds to flow east over the Caribbean and Atlantic. This wind shear tears the tops off thunderstorms, keeping tropical activity to a minimum. This is an easily observable effect that we experienced just this past summer. However, the warmer water can also alter the jet stream, which is how we most commonly feel its influence here in the United States.

The jet stream is a fast-moving river of air in the upper levels of the atmosphere that’s usually located between 25,000 and 35,000 feet, the typical cruising altitude for commercial jets. This ribbon of powerful winds is caused by the temperature difference between the tropics and the poles. Weather exists as a result of nature trying to balance itself out—in this case in the Northern Hemisphere, rising warm air in the tropics flows north toward the Arctic, turning east thanks to the Coriolis effect. The resulting river of westerly winds is the jet stream.

The subtropical jet stream over the southern U.S. on February 5, 2016. Source: Tropical Tidbits

During the summer months, the jet stream is usually weaker and stuck in the higher latitudes. This is why weather is generally calmer during the summer, allowing long stretches of hot, humid weather only broken by occasional pop-up thunderstorms. During the cooler months, however, the north-south temperature gradient is much sharper, allowing the jet stream to dive south over the United States (and sometimes even farther south than that). This curvy, dippy jet stream provides us a constant offering of volatile weather, bringing everything from heavy rain or snow to extreme bouts of cold weather.

This is where El Niño factors in. There are actually two jet streams in the Northern Hemisphere: the polar jet stream, which circulates in the higher latitudes, and the subtropical jet stream, which we’ll often find around the southern United States. The polar jet is what brings us our deep shots of frigid air during the dead of winter, and the subtropical jet is often at least partially responsible for the huge, historic snowstorms that occasionally whomp the East Coast.

When the water in the eastern equatorial Pacific Ocean is abnormally warm like it is during an El Niño, it can affect air temperature above the surface. The warmer air allows the subtropical jet stream to grow stronger and establish itself over the southern United States, shoving the polar jet stream farther north near the border between the U.S. and Canada. This brings stormy weather to the southern half of the United States, often manifesting itself in wet low-pressure systems that smack California before slowly trundling across the rest of the country. This also tends to keep the northern United States drier and warmer than normal, though snowy conditions and arctic blasts aren’t uncommon.

If you hear people talk about El Niño causing flooding and snow out west or news anchors report that “El Niño brought heavy rain to Los Angeles yet again today,” take comfort in the fact that you now know that’s not true. El Niño doesn’t directly cause rain or snow or heat or cold in the United States, and El Niño doesn’t make landfall like a hurricane, either, since it’s just abnormally warm ocean water. If all of that warm water ever comes ashore, we’ll probably have a few more problems than worrying about scientific accuracy and semantics. El Niño isn’t and won’t always be the cause of our weather woes this season, but it sure doesn’t help.

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6 Signs You're Getting Hangry
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Hangry (adjective): Bad-tempered or irritable as a result of hunger. This portmanteau (of hungry and angry) is not only officially recognized as a word by the Oxford English Dictionary, but it's also recognized by health experts as a real physiological state with mood-altering consequences.

That hangry feeling results from your body's glucose level dropping, putting you into a state of hypoglycemia, or low blood sugar. Glucose is the body's primary source of energy, so when you don't have enough, it affects your brain and other bodily functions, including the production of the hormones insulin and glucagon, which help regulate blood sugar. Check out the symptoms below to see if you've crossed over into the hanger danger zone.

1. IT TAKES EVERYTHING IN YOUR POWER JUST TO KEEP YOUR EYES OPEN.

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Glucose equals energy, so when your blood sugar levels are low, you may start wishing you were back in bed with the shades drawn. If you start feeling sluggish or tired even though you’re well-rested, you might just need to eat something.

2. THE EASIEST ITEM ON YOUR TO-DO LIST SEEMS LIKE AN IMPOSSIBLE TASK …

It’s hard to concentrate when all you can think about is whether you're going to order the fish or beef tacos for lunch. The distraction goes beyond fantasies about food, though. The brain derives most of its energy from glucose, so when it's low on fuel, a serious case of brain fog can set in. Confusion and difficulty speaking are among the more serious symptoms you may experience when you're hangry.

3. … AND YOU HAVE A BAD CASE OF WORD VOMIT.

Blame this on brain fog too. The gray matter in your noggin goes a little haywire when blood sugar is in short supply. That's why you may start stuttering or slurring your words. You might also have difficulty finding your words at all—it can feel like your mouth and brain are disconnected.

4. YOU’RE SHAKING LIKE A LEAF AND FEEL LIGHTHEADED.

Tremors and dizziness are both signs that you should pay closer attention to your body, which is screaming, "Feed me!" Once again, low blood sugar is often the culprit of trembling hands and feeling faint, and exhaustion and stress make the symptoms worse.

5. YOUR COWORKERS SEEM ESPECIALLY ANNOYING.

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You’re tense and irritable, and it’s starting to show. Hunger causes your body to release cortisol and adrenaline, the same hormones responsible for stress. This can put you on edge and lower your tolerance for other people’s quirks and irksome habits, which suddenly seem a lot less bearable.

6. YOU SNAPPED AT YOUR FRIEND OR PARTNER FOR NO GOOD REASON.

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Not only are you irritable, but you’re more likely to lash out at others because of it. The doses of adrenaline and cortisol in your body can induce a fight-or-flight response and make you go on the attack over matters that—if you had some food in you—would seem unimportant.

So what should you do if these descriptions sound all too familiar? Eat a snack, pronto—one with complex carbohydrates, lean protein, and healthy fats. The first one brings up your blood sugar level, and the other two slow down how fast the carbohydrates are absorbed, helping you to avoid a sugar crash and maintain a normal blood sugar level. Eating small meals every few hours also helps to keep hanger at bay.

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Astronomers Discover 12 New Moons Around Jupiter
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As the largest planet with the largest moon in our solar system, Jupiter is a body of record-setting proportions. The fifth planet from the Sun also boasts the most moons—and scientists just raised the count to 79.

A team of astronomers led by Scott S. Sheppard of the Carnegie Institute for Science confirmed the existence of 12 additional moons of Jupiter, 11 of which are “normal” outer moons, according to a statement from the institute. The outlier is being called an “oddball” for its bizarre orbit and diminutive size, which is about six-tenths of a mile in diameter.

The moons were first observed in the spring of 2017 while scientists looked for theoretical planet beyond Pluto, but several additional observations were needed to confirm that the celestial bodies were in fact orbiting around Jupiter. That process took a year.

“Jupiter just happened to be in the sky near the search fields where we were looking for extremely distant solar system objects, so we were serendipitously able to look for new moons around Jupiter while at the same time looking for planets at the fringes of our solar system,” Sheppard said in a statement.

Nine of the "normal" moons take about two years to orbit Jupiter in retrograde, or counter to the direction in which Jupiter spins. Scientists believe these moons are what’s left of three larger parent bodies that splintered in collisions with asteroids, comets, or other objects. The two other "normal" moons orbit in the prograde (same direction as Jupiter) and take less than a year to travel around the planet. They’re also thought to be chunks of a once-larger moon.

The oddball, on the other hand, is “more distant and more inclined” than the prograde moons. Although it orbits in prograde, it crosses the orbits of the retrograde moons, which could lead to some head-on collisions. The mass is believed to be Jupiter’s smallest moon, and scientists have suggested naming it Valetudo after the Roman goddess of health and hygiene, who happens to be the great-granddaughter of the god Jupiter.

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