A Volcanic Ash Advisory Center (VAAC) is a group of experts responsible for coordinating and disseminating information on atmospheric volcanic ash clouds that may endanger aviation. As at 2019, there are nine Volcanic Ash Advisory Centers located around the world, each one focusing on a particular geographical region. Their analyses are made public in the form of volcanic ash advisories (VAAs), involving expertise analysis of satellite observations, ground and pilot observations and interpretation of ash dispersion models. [1]
The worldwide network of Volcanic Ash Advisory Centers was set up by the International Civil Aviation Organization (ICAO), an agency of the United Nations, as part of the International Airways Volcano Watch (IAVW), an international set of arrangements for monitoring and providing warnings to aircraft of volcanic ash. The operations and development of the IAVW are coordinated by the Meteorology Panel (METP) established by the ICAO Air Navigation Commission. [2] [3] The individual VAACs are run as part of national weather forecasting organisations of the country where they are based, e.g. the US National Weather Service or the British Met Office.