“THE RECENT trend (of change) seems unprecedented in the historical model,” David Thompson of the University of Washington told reporters Thursday at a meeting of the American Geophysical Union.
 
Changes in the “polar vortex,” the pattern of winds which encircles the pole, may well be a sign of more severe weather shifts to come, he added. He and other scientists presented reports showing that, on balance, the polar vortex has tightened since 1970 — meaning that the upper-atmosphere winds are blowing in a smaller, stronger circle around the polar region itself.
 
As a result, frigid polar weather has not moved as far south during the Northern Hemisphere winter, leading to climate changes ranging from higher temperatures across Europe and Asia to a sharp decrease in Spanish rainfall.
 
Scientists also theorize the shifting polar vortex could be responsible for fiercer winter storms across western North American and western Europe as higher temperatures in the lower, more-populous latitudes clash with the very cold temperatures above the North Pole, generating high-altitude winds that later pull heat and moisture from the Atlantic and Pacific oceans.