http://news.discovery.com/earth/mystery-...160416.htm
EXCERPT: When Mt. Vesuvius erupted in the year 79, famously burying the town of Pompeii in ash, historian Pliny the Younger recorded that the volcano expelled “frightening dark clouds, rent by lightning twisted and hurled, opening to reveal huge figures of flame.” It was the first description of a phenomenon that, almost 2,000 years later, is the stuff of viral Internet photos: lightning that arcs its way through the ash plumes of some volcanic eruptions. It’s a phenomenon that has, however, puzzled scientists, who have wondered exactly how such lightning is generated. Two new papers, published in Geophysical Research Letters, the journal of the American Geophysical Union (AGU), have helped provide clarity and, in the process, unify two competing schools of thought....
EXCERPT: When Mt. Vesuvius erupted in the year 79, famously burying the town of Pompeii in ash, historian Pliny the Younger recorded that the volcano expelled “frightening dark clouds, rent by lightning twisted and hurled, opening to reveal huge figures of flame.” It was the first description of a phenomenon that, almost 2,000 years later, is the stuff of viral Internet photos: lightning that arcs its way through the ash plumes of some volcanic eruptions. It’s a phenomenon that has, however, puzzled scientists, who have wondered exactly how such lightning is generated. Two new papers, published in Geophysical Research Letters, the journal of the American Geophysical Union (AGU), have helped provide clarity and, in the process, unify two competing schools of thought....