An ash cloud is a dense cloud of ash particles that is released into the atmosphere during a volcanic eruption. These clouds can rise high into the sky and spread over large areas, affecting air quality and visibility. The ash consists of tiny fragments of rock, minerals, and volcanic glass, which can be harmful to both the environment and human health. When an ash cloud forms, it can disrupt air travel by causing flight cancellations and delays. Airlines often reroute flights to avoid areas affected by the ash, as it can damage aircraft engines. Monitoring organizations, such as the Volcanic Ash Advisory Centers, provide crucial information to help manage these risks.