El Nino Messes with Earth in Weird Ways
A shift of the winds can alter ocean temperature in the Pacific and weather patterns across the planet. Continue reading →
You may have seen some of the recent headlines warning of a "Monster" El Niño, possibly the most powerful one in history, which could have all kinds of dramatic effects on weather across our planet -- from more intense storms in the Pacific and a gentler hurricane season in the Atlantic, to a temperature boost that seems likely to ensure that 2015 will be the warmest year ever.
Which may lead you to wonder: What exactly is an El Niño, anyway? Is it some sort of freak natural event, or something that happens on a regular basis? And how much should you be worried about it? For those who aren't meteorologists or hard-core weather junkies, it's as bewildering of a dilemma in some ways as the dreaded polar vortex, a term that strikes fear into the hearts of suddenly shivering people each winter.
But don't worry. Here are some basic facts about the phenomenon, and how it affects us, from sources such as the National Oceanic and Atmospheric Administration, NASA's Earth Observatory website and the University Corporation for Atmospheric Research.
El Niño basically is a temporary warming of the waters of the equatorial central and eastern Pacific Ocean. Official definitions vary a bit, but by NOAA's standards, we're having an El Niño when surface temperatures rise in that area by at least 1 degree Fahrenheit for three months or more in a specific section of the ocean that government scientists monitor.
Typically, the temperature shift is 1 to 3 degrees Fahrenheit, and it usually lasts from nine months to a year, though sometimes it persists even longer. Though the frequency of El Niño is irregular, it usually happens fairly often -- about every two to seven years.
What causes it? Basically, a change in wind patterns. According to NASA, the Pacific receives more sunlight than any region on Earth, most of which is stored in the water in the form of heat. Typically, the Pacific trade winds blow from east to west, pulling the warm surface water westward, where it accumulates in a large, deep pool around Indonesia and Australia. As that happens, the deeper, colder waters in the eastern Pacific rise to the surface. That's the basic circulation pattern.
But every so often, the winds pushing that natural conveyor belt weaken. There are different reasons why this may happen, but subtle shifts in the Earth's orbit around the sun is one major factor, according to a 2014 study by University of Wisconsin researchers, who used computer models to look at El Niño over more than a 20,000-year period.
In any case, the result is that not as much water gets moved around. That causes the waters of the equatorial central and eastern Pacific to get warmer. As the waters warm, they have a feedback effect, weakening the winds even more. That causes the ocean to get even warmer, and makes an El Niño grow more powerful.
So why is that a big deal? Changing the temperature in one part of the ocean can have all sorts of strange effects. In the east, the water expands, raising the sea level by as much as a foot, according to NASA. And slowing the conveyor belt that brings cold water to the surface also decreases the supply of nutrients that feed phytoplankton, the tiny organisms near the surface that fish and marine mammals depend upon for food. That can be a big problem for coastal areas where many people depend on fishing for their livelihood.
As the warm water moves eastward, more heat and moisture rise into the atmosphere there, which disrupts the usual global weather patterns and shifts the jet stream over the western Pacific eastward. In the eastern Pacific, that means more storms, which translate into more rainfall in places like California. (That's one reason that residents of the drought-ravaged state may see El Niño as a savior.)
At the same time, the atmospheric shifts caused by El Niño can also lower the probability of hurricanes in the Atlantic and cause severe drought in Australia, Indonesia and parts of southern Asia. A really powerful El Niño, such as the one in 1982-83, can cause billions in damage from floods, storms, crop-ruining droughts and forest fires across the planet.
El Niño can drive up global atmospheric temperature, too, but predicting exactly how much is tricky, because that number is affected by numerous other factors as well, according to NOAA's Climate.gov. But scientists say that its presence raises the possibility that 2015 will set a new temperature record.
Finally, we should mention that El Niño actually is part of a bigger phenomenon called the El Niño-Southern Oscillation cycle, or ENSO. There's also another phase, called La Niña, in which the Equatorial central and eastern Pacific is colder than usual. That results in cooler temperatures in the Pacific Northwest and warmer winters in the Southeast.
The winners are in from the National Oceanic and Atmospheric Administration's "Weather in Focus" photo contest, picked from more than 2,000 entries taken between Jan. 1, 2014 and March 31, 2015. "From rainbows and sunsets to lightning and tornadoes, the winning photos aren’t just captivating to look at, but inspire us to look at the world in different ways," said Douglas Hilderbrand, NOAA's contest judge and Weather-Ready Nation Ambassador Lead. "It was difficult to pick winners from so many good entries." In first place, from the category "Science in Action," is "Green Bank Telescope in WV" by Mike Zorger, Falls Church, Va.
All 16 winning images will be displayed in a
exhibit located on the NOAA campus in Silver Spring, Md., starting in July. Second place in "Science in Action" went to "Photographer captures the aurora" by Christopher Morse, Fairbanks, Alaska.
In third place: "Atmospheric Research Observatory" by Joseph Phillips, Boulder, Colo.
And honorable mention also went to Joseph Phillips, Boulder, Colo. for "Atmospheric Research Observatory."
In the category "Weather, Water & Climate," first place went to "Snow Express" by Conrad Stenftenagel, Saint Anthony, Ind.
In second place was "Proton arc over Lake Superior" by Ken William, Clio, Mich.
"With a Bang" by Bob Larson, Prescott, Ariz., won third place in the "Weather, Water & Climate" category.
Honorable mention went to Alana Peterson, Maple Lake, Minn. for "Raindrops on a Leaf."
A second honorable mention was won for "Fire in the Sky over Glacier National Park" by Sashikanth Chintla, North Brunswick, N.J.
In the category "In the Moment," first place went to "Smoky Mountains" by Elijah Burris, Canton, N.C.
Second place went to "Spring Captured: Freezing rain attempts to halt spring" by Mike Shelby, Elkridge, Md.
And third place went to "Rolling clouds in Lake Tahoe" by Christopher LeBoa, San Leandro, Calif.
Of course the professionals had their own category. First place was won by Brad Goddard, Orion, Ill., for "Stars behind the storm."
Brad Goddard pretty much cleaned up this category, winning second (and third) place with "A tornado churns up dust in sunset light near Traer, IA."
Third place went for "A tornado crosses the path, Reinbeck, IA" by Brad Goddard.
“Fog rolls in from the ocean on a hot summer day, Belbar, N.J.” by Robert Raia, Toms River, N.J., won honorable mention in the pro category.