By Sid Perkins
From Acapulco, Mexico, at a meeting of the American Geophysical Union
During the 1930s, immense clouds of dust wafting over the Great Plains blocked so much sunlight that temperatures there were significantly lower than normal during summer months, a new analysis suggests.
From 1930 to 1938, an extended drought transformed the central United States into the Dust Bowl of popular legend. That dry spell, like many others that have struck the United States, occurred during a lengthy La Niña, when sea-surface temperatures in the central Pacific were cooler than normal (SN: 8/10/02, p. 85).