Volcanic eruptions in high latitudes can greatly alter climate and distant river flows, including the Nile, according to a recent study funded in part by NASA. Researchers found that Iceland’s Laki volcanic event, a series of about ten eruptions from June 1783 through February 1784, significantly changed atmospheric circulations across much of the Northern Hemisphere. This created unusual temperature and precipitation patterns that peaked in the summer of 1783, including far below normal rainfall over much of the Nile River watershed and record low river levels. The study provides new evidence that large volcanic eruptions north of the equator often have far different impacts on climate than those in the tropics. ‘While considerable research has shown that eruptions in the tropics influence climate in the Northern Hemisphere winter, this study indicates that eruptions in high-latitudes produce changes in atmospheric circulation in the Northern Hemisphere summer,’ said lead author Luke Oman, Rutgers University, New Brunswick, N.J. Using a sophisticated computer model developed by NASA’s Goddard Institute for Space Studies, New York, the researchers linked the Laki eruptions to a cascade of effects that rippled across much of the Northern Hemisphere, altering surface temperatures that ultimately resulted in much below […]