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MJO
Wed Jun 18, 2003
Listen in RealAudio 
Hi, I'm Bryan Yeaton for The Weather Notebook
Back in 1971, two scientists named Roland Madden and Paul Julian analyzed a decade's worth of
readings from the tropical Pacific and discovered that the atmosphere down there periodically
coughs up a massive bubble of acute meteorological disturbance. An armada of high-topped
clouds rises over the Indian Ocean and then sails east, inundating Indonesia before invading
the western Pacific. Strong westerlies blow over the western Pacific, while at 50,000 feet,
fitful gusts created by rapidly rising air columns circle the globe. This atmospheric kink,
dubbed the Madden-Julian Oscillation or MJO, takes between 30 and 60 days to work itself
out.
Pretty interesting - but so what? Well, in the past few years, some atmospheric scientists
have begun to connect the MJO with weather anomalies around the world. For starters, there is
strong evidence that the MJO enhances and may even trigger El Niņo. A recent study has
correlated MJO-generated winds in the eastern Pacific with the genesis and intensity of
hurricanes in the Gulf of Mexico and Caribbean. And finally, the MJO significantly roils the
weather in Western North America, bringing a deep chill to western Canada while winter storms
pound the Pacific Northwest. One Seattle meteorologist has started issuing informal 3 to 4
week local forecasts based on MJO activity in the Indian Ocean.
Still, the MJO presents one big forecasting catch: no one can yet predict when a new cycle
will fire up, but that should provide plenty of opportunity for future researchers.
Today's show was sent in by David Laskin. The Weather Notebook is produced with support from
Subaru of America and the National Science Foundation.
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