Do you remember the Eyjafjallajokull eruption of 2010? Of course you do. It closed massive chunks of European airspace for around a week and caused one heck* of a disruption.

*Heck is the official term for between 95,000-107,000 flight cancellations impacting some 10 million passengers.

Why was it so big? Well, you would have to ask Eyjafjallajokull that (ok, fine, it’s a stratovolcano fed by a huge magma chamber, and the ice cap and resulting steam and the pressure build up are what contributed to such an mighty meltdown).

But the real meltdown—that of European aviation—was due to a few things. The top two being a) volcanic eruptions lead to ash and b) airplanes don’t like ash.

There are a few other key things to note as well though. For example, how much ash is too bad for aircraft, in terms of the composition of ash clouds, was not super well studied back then. This resulted in everyone going “any is bad” (this has since been looked into more).

And while responses to disasters and airspace closures were thought about, they weren’t to this scale meaning everyone was just not really prepared and everything shut for ages.

Where are we at with it all now

Well, ICAO and EASA and any other authority for a region that gets impacted by volcanoes now run VOLCEX simulations. That means Volcanic Ash Exercises, and these are aimed at testing contingency procedures and building up coordination, response and communication policies to help in the event of another one happening.

In order to keep folk informed on what’s popping and spitting around the world, we have nine Volcanic Ash Advisory Centers (VAACs). These each monitor volcanoes in their region and issue advisories on any pertinent volcanic rumblings.

Here is what we saw for the latest eruption to occur which impacted aviation, the Hayli Gubbi volcano in Ethiopia:

It popped its top on November 23, and the initial ash plume headed up to around 45,000’ (FL450) and hitched a ride on a jet stream over the Arabian Peninsula, Pakistan, India and towards China.

What’s the problem?

Well, you will see a line in the text bit which says ‘Aviation Colour Code’ and then ‘Unknown’. This is because most of the ash cloud was obscured in satellite imagery meaning assessing the amount of ash and where it was, was hard to do, and this makes it hard for operators to decide whether its ‘bad’, ‘very bad’ or a ‘just keep flying through it’ sort of a level.

Generally, if the risk cannot be assessed then flights will divert around possible risk areas, but it does mean you waste a lot of fuel and time, or can potentially head into a region that actually is still ‘too high’ a risk.

If they do head through by accident, there are signs and procedures for pilots to follow to help them mitigate the effects of ash. The main one being ‘turnaround’. The second one being a checklist to try and keep the engines running*.

*The only all engines out because of volcanic ash event was way back in 1989 and they did get them started enough to land somewhere relatively safely.

So what’s new now?

The UK Met Office and Meteo France are becoming the first to launch a new volcanic ash forecasting service, and it is going to be much more detailed.

Mark the date in your calendars (or just remember it because it’s coming up soon: November 27, 2025

The QVA (Quantitive Volcanic Ash) forecasts will use a gridded system showing 12 horizontal slices of the atmosphere. A sort of a Damian Hirst style if you like. These will start at ground level and go up to 60,000’, with each level 5000’ deep, and updates will be issued every 6 hours while ash is thick ‘n’ heavy.

The big difference is the shift away from the ‘what we can actually see’ reporting, and more of a forecasting based on environmental specifics, as well as including more consideration to engine and airframe volcanic ash certification standards (remember the ‘how must is too bad’ measurements).

Those specifics, in case you’re wondering, are

• Eruption Source Parameters: So location, height, ash properties etc. Basically the ‘what actually came out’ info
• Observational Data: Satellite, LIDAR and any other imagery
• Data-fusion: Combining observations with clever forecasting stuff
• MOGREGPS-G: Which sounds like the DJ name of a volcano goblin, but is actually a system which helps determine and show forecast uncertainties.

All this means operators should hopefully be able to make more informed decisions about whether to fly through areas, and ATS will be able to reduce airspace closures and the closure areas a little more, making everything a little bit safer and more efficient.

Tell me more

Alrighty then.

The QVA will consist of three core data sets:

• Expected Ash Concentration: A gridded dataset providing specific 3-dimensional ash concentration location details. 
• Probability of Ash Exceedance: A dataset indicating the likelihood of ash exceeding key concentration thresholds (0.2mg/m³, 2mg/m³, 5mg/m³, and 10mg/m³). 
• Feature Objects (IWXXM Format): Representations of areas where ash exceeds concentration thresholds at various flight levels. 

Here’s an image of the concentration forecast for the FL150-FL200 layer.

These will be sent out via VAA bulletins so that flight planners can plan more, and pilots will still receive ash advisories and other information in their briefing packs as well.

Get more info here: MET Office QVA Forecasts