In 2010, ash from Iceland’s Eyjafjallajökull volcano disrupted flights across Europe and cost the airline industry around £1billion in lost revenue. Since then, governments have invested heavily to understand how volcanic ash plumes develop. With volcanic activity at Iceland’s Bárðarbunga volcano increasing, and local flights across Alaska cancelled in June last year due to eruptions from the Pavlof volcano, the need to understand ash plumes is more important than ever.

‘A big problem is knowing how much volcanic ash is coming out of an eruption. There’s considerable uncertainty in this area,’ says Professor Jim Haywood, a Met Office scientist. ‘There are a number of initiatives to validate the Met Office modelling of volcanic ash.’

One such initiative comes from the Civil Aviation Authority, which has established ground-based lidar (or ‘light radar’) sites across the UK. Lidar uses a laser to illuminate a target, and then analyses the reflected light. ‘Essentially, lidar can give you the altitude for volcanic ash,’ says Haywood. Lidar data are supported with information from sun-photometers, which detect ash concentration.

Another approach comes from ZEUS, a prototype device that measures atmospheric ash using static electricity. Created through a collaboration between the Met Office and the Natural Environment Research Council, ZEUS has already been mounted to a British Airways 747 and has undergone successful flights to South Africa. It will now be flown on long-haul flights around the world for a year collecting data. ‘ZEUS has the potential to provide a clearer picture of ash distribution and could be used to inform decision making-processes in the event of future eruptions,’ says Captain Dean Plumb from British Airways.

The Met Office also uses its own small plane – the Met Office Civil Contingency Aircraft (MOCCA) – to gather information on ash clouds. This two-man, one-scientist Cessna 421 can be scrambled during eruptions to sample an ash plume as it develops. MOCCA flies above the ash layer to gather information using lidar and measures particles collected through wing-mounted instruments. The findings are returned to the London Volcanic Advisory Centre, a Met Office centre tasked with monitoring eruptions in Iceland and the northwest Atlantic.

This story was published in the January 2015 edition of Geographical Magazine