A study by scientists, from the universities of Würzburg, Hamburg and Lancaster, has shown that a new generation of tiny satellites, due for launch in 2020, have the potential to substantially reduce the uncertainties in current models used to predict ash dispersal from volcanic eruptions.

Uncertainty about where ash clouds would spread after previous eruptions has meant that thousands of kilometres of airspace have been closed to aircraft as a precaution, leaving holidaymakers stranded and costing billions of pounds in lost business.

Dr Klemen Zakšek, the lead author on the study, won first prize at the 3rd Mission Idea Contest for Micro/Nano-Satellite Utilization in 2014 with a proposed mission for photogrammetric observations of volcanic clouds - photogrammetry uses a series of photographs of the same scene to build 3D models.

Prof Klaus Schilling from the Center of Telematics at the University of Würzburg spotted the potential of the photogrammetry proposal and suggested that it matched well with the aims of the planned Telematics Earth Observation Mission (TOM)

The primary goal of TOM is providing accurate satellite data to improve predictive modelling of ash clouds. The mission consist of three picosatellites - tiny satellites that have many benefits over classic satellites including simpler and cheaper designs and faster build times, allowing many more units to be deployed. The TOM satellites, which are around the size of a domestic toaster and equipped with cameras, are planned to launch in 2020.

Klemen, originally from the University of Hamburg and now at the University of Ljubljana (Slovenia), wanted to provide proof of concept for his idea before the launch of the TOM technology. So he needed photographs of a volcanic eruption taken from space, which he could use as a proxy for the TOM imagery of the future.

He got access to photos of a 2009 eruption of the volcano Sarychev Peak, taken by astronauts through the windows of the International Space Station, but then struggled with the photogrammetry involved. He turned for help to Dr Mike James from the Lancaster Environment Centre at Lancaster University, who combines a background in volcanology, with expertise in photogrammetry.

“We wanted to better understand the early part of an eruption,” said Mike. “The biggest uncertainty when forecasting where ash will disperse in the atmosphere is the amount and size of the ash particles initially injected into the atmosphere, and how high they ascend.

“This is critical for accurately modelling how the plume will then disperse down wind and into the flight paths of aircraft,” said Mike. “Uncertainties at this early stage can give much larger uncertainties in the down wind models which are used to predict the spread of the ash plume.”

Using the space station photos, Mike built sequential 3D models of the growing ash plume from the Sarychev Peak eruption. These were then used by Klemen and his former colleague Prof Matthias Hort from the University of Hamburg, to create an eruption model, showing how much material per second came out of the volcano and how high it reached.

“This is strong support for the TOM proof-of-concept mission, aimed at reducing uncertainties in forecasting the spread of ash clouds,” said Mike.

Mike and his colleagues are now waiting for some more photographs to advance their simulations. They hope to get some images from the 57th International Space Station mission, happening in May–December 2018. Its commander, Dr Alexander Gerst, is a volcanologist as well as an astronaut and has promised to take photographs of volcanic eruptions from space if the opportunity arises.