This picture of Mt. St. Helens illustrates the giant ash column of a volcano called the eruption column. This column of ash can sometimes rise to the stratosphere, where it is more difficult for the particles to be removed from the atmosphere. In that case, the ash column of a volcano can affect the weather for months to come, as was the case with the 199x eruption of Mt. Pinatubo.
This is page 6 of 23