article_snippet.sent: Just like in a thunder cloud, electric charge in the ash cloud eventually builds up until electric charge in the ash cloud seeks a path through to the ground as lightning.
article_snippet.sent: scientists found that the intense heat generated by the lightning bolts causes the ash to melt into spherules of smooth glass.
article_snippet.sent: scientists at the Ludwig Maximilian University of Munich found that the movement of ash particles against each other as scientists at the Ludwig Maximilian University of Munich go from the compressed environment under the Earth's surface into the atmosphere during an eruption causes a built of up static charge.
article_snippet.sent: When the ash reaches the atmosphere, the energy is discharged as lightning bolts.
highlights_snippet.sent: Strikes caused by high levels of electric charge building up as ash particles  rub together .
  