Volcanic ash clouds are formed when a volcano erupts, releasing tiny fragments of rock, minerals, and volcanic glass into the atmosphere. These particles can be carried by winds over long distances, affecting air quality and visibility. The ash can also disrupt air travel, as it poses risks to aircraft engines. The composition of volcanic ash varies depending on the type of eruption and the materials involved. Ash clouds can contain harmful gases, such as sulfur dioxide, which can lead to acid rain and other environmental issues. Monitoring these clouds is crucial for public safety and aviation management, especially near active volcanoes like Mount St. Helens or Kilauea.