In addition to gases like sulfur dioxide,
huge amounts of ash (very small particles of rock material)
were injected into the atmosphere by the eruption.
Small particles of dust, smoke, and
volcanic ash suspended in the air are called aerosols.
The Aerosol Index (also measured by TOMS instruments)
is a measure of the relative amount of aerosols in the
atmosphere. This animation shows the Aerosol Index for
six days after Mount Pinatubo's main eruption. The eruption
is not the only source of worldwide aerosols, but you
can easily follow the "cloud" it generated
through the animation.
! Click the image to see the animation.
Step through the frames to examine the behavior of the