Volcanic Ash and Aviation—The Challenges of Real-Time, Global Communication of a Natural Hazard

Abstract

More than 30 years after the first major aircraft encounters with volcanic ash over Indonesia in 1982, it remains challenging to inform aircraft in flight of the exact location of potentially dangerous ash clouds on their flight path, particularly shortly after the eruption has occurred. The difficulties include reliably forecasting and detecting the onset of significant explosive eruptions on a global basis, observing the dispersal of eruption clouds in real time, capturing their complex structure and constituents in atmospheric transport models, describing these observations and modelling results in a manner suitable for aviation users, delivering timely warning messages to the cockpit, flight planners and air traffic management systems, and the need for scientific development in order to undertake operational enhancements. The framework under which these issues are managed is the International Airways Volcano Watch responsible for observing, analysing, forecasting and communicating the aviation hazard (airborne ash), using agreed techniques and messages in defined formats. Continuous improvement of the IAVW framework is overseen by expert groups representing the operators of the system, the user community, and the science community. The IAVW represents a unique marriage of two scientific disciplines, volcanology and meteorology, with the aviation user community. There have been many multifaceted volcanic eruptions in complex meteorological conditions during the history of the IAVW. Each new eruption brings new insights into how the warning system can be improved, and each reinforces the lessons that have gone before. The management of these events has improved greatly since the major ash encounters in the 1980s, but discontinuities in the warning and communications system still occur. A good example is a 2014 ash encounter over Indonesia following the eruption of Kelut where the warnings did not reach the aircraft crew. Other events present enormous management challenges-for example the 2010 Eyjafjallajökull eruption in Iceland was, overall, less hazardous than many less publicised eruptions, but numerous small to moderate explosions over several weeks produced widespread disruption and a large economic impact. At the time of writing, while there has been hundreds of millions of US dollars in damage to aircraft from encounters with ash, there have been no fatalities resulting from aviation incidents in, or proximal to volcanic ash cloud. This reflects, at least in part, the hard work done in putting together a global warning system-although to some extent it also reflects a measure of good statistical fortune. In order to minimise the risk of aircraft encounters with volcanic ash clouds, the global effort continues. The future priorities for the IAVW are strongly focused on enhancing communication before, and at the very onset of a volcanic ash-producing event (typically the more dangerous stage), together with improved downstream information and warning systems to help reduce the economic impact of e...

Optical and geometrical aerosol particle properties over the United Arab Emirates

“…Additionally, aerosol particles are tied to health (Davidson et al, 2005), biological processes (Kanakidou et al, 2018;Moore and Braucher, 2008) and aviation safety (Guffanti et al, 2010;Lechner et al, 2017). Mineral dust is one of the most mass abundant types of primary aerosol particles emitted into the atmosphere (Kok et al, 2017).…”

An adaptation of the CO<sub>2</sub> slicing technique for the Infrared Atmospheric Sounding Interferometer to obtain the height of tropospheric volcanic ash clouds

“…They are commonly used to demonstrate the utility of new remote sensing developments (e.g. Mackie and Watson, 2014;Taylor et al, 2015;Ventress et al, 2016;Western et al, 2017) and similarly are often used in modelling research (Matthias et al, 2012;Webster et al, 2012;Moxnes et al, 2014;Wilkins et al, 2016). This makes them the ideal first candidates for the CO 2 slicing technique.…”

“…In extreme cases, these have resulted in engine failure (Miller and Casadevall, 2000;Chen and Zhao, 2015) and subsequently life-threatening circumstances. Ash clouds are closely monitored by the Volcanic Ash Advisory Centre (VAAC), who use a variety of data sources including information from volcano observatories and satellite data (Prata and Tupper, 2009;Thomas and Watson, 2010;Lechner et al, 2017). This allows informed decisions on the closure of airspace following an eruption, which can result in severe disruption and have significant financial implications.…”

“…This has included detection schemes which flag pixels that contain volcanic ash (e.g. Prata, 1989a, b;Ellrod et al, 2003;Pergola et al, 2004;Filizzola et al, 2007;Clarisse et al, 2010;Mackie and Watson, 2014;Taylor et al, 2015). Other methods have been developed to quantify parameters such as the mass, ash optical depth (AOD), effective radius and altitude of the ash cloud, usually relying on look-up tables or optimal estimation techniques (e.g.…”

Review of `Analysis of properties of the 19 February 2018 volcanic eruption of Mount Sinabung in S5P/TROPOMI and Himawari satellite data' by de Laat et al.

“…I suggest changing to 'Evaluation of Himawari-8 geostationary InfraRed (IR) brightness temperature differences...'. P2L35: 'global monitoring of volcanic eruptions..' -Volcanic Ash Advisory Centers began to do this in 1987 under the International Airways Volcano Watch (see Lechner et al, 2017). This could be mentioned here as well.…”