Dust, ash, or other particulate matter commonly suspended in the atmosphere after volcanic eruptions. After explosive eruptions the dust may be thrown to heights of 20–30 km or more. The fall-out times of dust particles are quite short, a matter of days or weeks, depending on altitude and precipitation. Volcanogenic aerosols, usually sulphates, may linger for months, spreading as a long-lived veil in the stratosphere over much of the Earth.
Subjects: Meteorology and Climatology.