Support to Aviation for Volcanic Ash Avoidance
This project addresses the important problem of providing accurate and timely satellite-based information to Volcanic Ash Advisory Centres (VAACs) with the goal of improving and supporting services to the aviation community. There are now numerous sources of imagery and sounder data from both operational and research satellite sensors that can be used to identify and track airborne volcanic debris.
However, there are no standard data products speciﬁcally designed for volcanic ash and volcanic gas (principally SO2) and this has led to a number of ad hoc approaches and systems, and a lack of data product coordination between various VAACs. Despite the lack of standard products there are several mature techniques available from the research community that could be implemented for operational use. There are also no internationally agreed satellite-based volcanic product standards and no protocols or procedures in place to permit speciﬁcation of safe limits for aviation encountering airborne volcanic substances. Part of this problem lies with the lack of sufﬁcient information regarding what constitutes safe operating limits when ﬂying near to volcanic clouds.
Part of the solution lies in being able to provide quantitative satellite information and some means for validation. Another important factor in providing support to the aviation industry is timeliness. Most danger to jet aircraft occurs within 3 hours of a volcanic eruption and often the most critical time period is during the night, when visual identiﬁcation of airborne volcanic hazards is reduced. Once volcanic debris has been correctly identiﬁed, either through satellite detection of ash or SO2 , sophisticated atmospheric dispersion models can be run to predict the path of the volcanic clouds. The injection height of the volcanic debris is a critical piece of information in this process. Currently, there is no objective means for determining the injection height of a volcanic eruption, and usually multiple dispersion simulations must be run and matched “by eye” to current or prior satellite imagery. This is a subjective process that takes time and can lead to errors or very conservative predictions on regions of airspace deemed safe for ﬂying.