Aerosols & volcanic ash warning

Solar wind - Heliosphere
Magnetosphere
Planetary atmospheres
Radiation belts
Comets, Asteroids,
Meteors and Dust

Ionosphere
Atmospheric chemistry
Atmosphere & biosphere
Electromagnetic radiation

Mission scenarios
Instrument design
and technology
Mission operations
Data management

Impact on the safety of air traffic and on human health

Volcanic eruptions may eject large amounts of ash (aerosols) and trace gases such as sulphur dioxide (SO2) into the atmosphere. These ejecta can have considerable impact on the safety of air traffic and on human health. Ground-based monitoring is carried out at only a limited number of volcanoes: most volcanoes are not monitored on a regular basis, in particular the remotely located volcanoes.

Global observations of SO2 and aerosols derived from satellite measurements in near-real time may therefore provide useful complementary information to assess the possible impact of volcanic eruptions on air traffic control and public safety.

The Support to Aviation Control Service (SACS) focuses on the timely delivery of SO2 data derived from different satellite instruments.

Impact of aerosols on incoming solar radiation

During a volcanic eruption sulfuric gasses are injected into the stratosphere, where they convert to sulfate aerosols (sub-micron droplets containing about 75 percent sulfuric acid).

Following an eruption a large amount of these particles are formed and a large amount of aerosols fall back to the lower layers of the atmosphere. This explains why the impact of aerosols on incoming solar radiation varies significantly depending on if one is in a period of low or high level volcanic activity.

For example, when the Pinatubo volcano erupted in June 1991, scientists estimated that about 10% of the solar radiation was lost at the Earth’s surface, in comparison to about 0.1% the month before.

Mount St. Helens erupts

BIRA-IASB database and user interface for stratospheric aerosols