The threat of volcanic ash to the safety of aircraft operations is well established. Very dramatic encounters over the past 20 years have clearly demonstrated this problem. Since high altitude ash clouds can travel over long distances, the problem is a global one.
In response to this threat, the International Civil Aviation Organization (ICAO) has implemented the International Airways Volcano Watch (IAVW) in collaboration with the World Meteorological Organization (WMO). Many agencies and players collaborate in this effort. The objective is to ensure that a real-time operational response can be provided to the aviation community.
As part of this effort, nine Volcanic Ash Advisory Centers (VAAC) are designated to provide real-time guidance about the displacement and dispersion of the volcanic ash plume. to identify volcanic ash clouds through satellite images/data and other means; and to prepare/issue advisory messages. Various models are used by the VAACs to produce the guidance: the Volcanic Ash Forecast, Transport and Dispersion Model (VAFTAD), the CANadian Emergency Response Model (CANERM), the Modele Eulerien de Dispersion Atmospherique (MEDIA), etc.
The VAACs are faced with a number of scientific challenges:
- Eruption parameters are largely unknown (what initial data do we input in the forecast model?);
- Eruptions are often hard to detect;
- Volcanic ash in the atmosphere is not easily identified;
- Assimilation of plume data in forecast models is not done;
- Concentrations at which volcanic ash becomes a threat to aviation are not known;
- etc.
There are also so very practical / operational challenges for the VAACs. They include:
- How to ensure consistency in the information provided to and by the various partners;
- Coordination of information across areas of responsibility;
- Needs for backup, testing and comparisons;
- etc.
These challenges are important factors than can influence the ability to alert rapidly and to deliver timely and reliable advice. Finding and implementing solutions to these challenges will require time, effort and international collaboration. Already, we all benefit from long standing close working relationships among various players, agencies, and stakeholders around the world with keen interests in the volcanic ash problem. It must also be recognized that great advances have been made in this area over the last few years thanks to the work of many, including ICAO's Volcanic Ash Warning Study Group (VAWSG).
The 8th Conference on Aviation, Range, and Aerospace Meteorology