Mt. Etna Sulfur Dioxide Plume From
  NASA Atmospheric Infrared Sounder

Mount Etna, a volcano on the island of Sicily, erupting in late October, 2002. Mount Etna is Europe’s largest and most active volcano. This image from the Atmospheric Infrared Sounder on NASA’s Aqua satellite shows the sulfur dioxide (SO2) plume in shades of purple and black. Climate may be affected when large quantities of SO2 are injected into the atmosphere.