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article imageNASA scientists: A strange thing is happening in the stratosphere

By Karen Graham     Sep 4, 2016 in Science
Greenbelt - For 60 years, scientists have watched the wind circulation patterns in the stratosphere, that stretch of the atmosphere that extends about 10 to 30 miles above the Earth. And in all that time, they have remained the same, that is, until late in 2015.
The wind circulation pattern is called the "quasi-biennial oscillation" or QBO. NASA scientists have been observing it since 1953, and it did not appear to have any impact on weather or climate as we experience it on the Earth's surface.
The QBO's wind circulation is a recurring pattern that takes place every 28 months, miles above the Earth's surface. And this almost clock-like recurring pattern has had scientists wondering what would happen if it suddenly changed. What would it mean, and what effects would it have?
"The quasi-biennial oscillation is the stratosphere's Old Faithful," said Paul Newman, Chief Scientist for Earth Sciences at NASA's Goddard Space Flight Center, Greenbelt, Maryland, according to Science News Online. "If Old Faithful stopped for a day, you'd begin to wonder about what was happening under the ground."
The stratosphere sit above the Earth s troposphere  the site of all weather on Earth.
The stratosphere sit above the Earth's troposphere, the site of all weather on Earth.
NASA
Over the last 60 years, the QBO has always circulated the planet in an alternating easterly and westerly direction, taking about two years. Westerly winds develop at the top of the stratosphere and descend downwards, and are replaced by easterly winds above them. Then the easterlies descend and are replaced by the westerlies above them, and so it has gone, until the winter of 2015-2016.
The QBO throws a curve-ball
Near the end of 2015, when the Westerlies were supposed to be starting their downward descent and the easterlies were supposed to be replacing them, something unprecedented happened. The westerlies appeared to be moving upward, blocking the easterly winds' downward movement.
This new pattern held for six months before the easterly winds finally replaced the westerlies back on top again in July when the regular old pattern appeared to have resumed. "It's really interesting when nature throws us a curve-ball," Newman said, reports Gizmodo.
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UCAR
The stratosphere and the QBO
The QBO seems to have an influence on conditions in the stratosphere, according to the paper NASA published in the journal Geophysical Research Letters. Scientists found that the amount of ozone at the Equator changes about 10 percent between the peak phases of the easterlies and westerlies.
They found that the oscillation effect has an impact on the ozone levels in the polar regions. We know, too, that large volcanic eruptions or meteorite impacts can fling particles up into the stratosphere where they may linger for months, affecting the Earth's global climate.
Newman and his colleagues are now studying the causes and potential impacts associated with the now documented anomaly in the QBO. They have a couple of theories, as yet unproven. One theory suggests the change in circulation was a side-effect of the massive El Nino we just went through. The second theory asks the question - is this an effect of the rising temperatures and warming climate here on Earth?
Newman and his associates now have to figure out if this was a "black swan," a once-in-a-generation event, or a "canary in the coal mine," a warning to us of unforeseen events yet to come.
More about Stratosphere, QBO, Curveball, El Nino, Climate change
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