Study pinpoints location of world's worst weather extremes
Tuesday, June 24, 2014, 6:31 PM - Strong atmospheric currents steer extreme weather to the same parts of the planet time and time again, according to a new study.
Atmospheric currents swish back and forth across the hemisphere about 5 km above the surface in a giant wave pattern.
There are also vertical pressure waves that force air around the globe and, in the process, pick up cold air from the Arctic and warm air from the tropics.
Extreme weather arises when the waves come to a halt, trapping storms or temperature fluctuations that can persist for weeks at a time. The air flow can also trigger rain by "steering" storms over a community.
Researchers from the University of Exeter and the University of Melbourne have determined that the wave patterns leave the Northern Hemisphere more prone to these weather extremes.
"We're not saying these extremes are becoming more prevalent," lead study author James Screen of the University of Exeter told Live Science.
"These waves have preferred locations, so you're more likely to get extreme weather in one place over another."
The team analyzed extreme weather events from 1979 to 2012 and determined that the waves halt in the same locations repeatedly because geographical features like mountain ranges and oceans.
The complete paper was published Monday in the journal Nature Climate Change.