Abstract: The International Civil Aviation Organization (ICAO) and other Aviation
concerns recognized the need to keep aviators informed of volcanic hazards. To
that end, nine Volcanic Ash Advisory Centers were created. These centers are
tasked with monitoring Volcanic Ash plumes with in their assigned airspace.

Each VAAC is responsible for providing Volcanic Ash Advisories (VAA)
whenever an volcanic event ... occurs in their area of responsibility.

Anchorage VAAC - Anchorage, AK, United States
Buenos Aires VAAC - Buenos Aires, Argentina
Darwin VAAC - Darwin, Australia
London VAAC - London, United Kingdom
Montreal VAAC - Montreal, Canada
Tokyo VAAC - Tokyo, Japan
Toulouse VAAC - Toulouse, France
Washington VAAC - Washington, DC, United States
Wellington VAAC - Wellington, New Zealand

Each Volcanic Ash Advisory Center performs these functions:
- Develop and execute numerical meteorological and volcanic ash
dispersion numerical models in real-time.
- Continuously obtain and use satellite information to discriminate
volcanic ash clouds from weather clouds.
- Issue Volcanic Ash Advisories (VAAs), and provide guidance to World
Meteorological Organizations (WMOs) for Sigmet issuance involving
volcanic ash.
- Provide advisory service to Regional Area Forecast Centers (RAFCs),
Meteorological Watch Offices (MWOs) and other VAACs.
- Coordinate aviation and public information about volcanic episodes
with the national and international volcanic community.
- Provide adequate communications with the aviation and public
community and other VAACs.