Local sources major cause of US near-ground aerosol pollution

A cloud of pollution hangs over the Eastern United States in this image captured in July 2002 by NASA's Moderate Resolution Imaging Spectroradiometer (MODIS). The majority of such haze originates locally in North America, and only a small amount is imported from other continents, new research suggests. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC