Mystic Met closed Europe with computer model
And not much data
So the UK Met Office closed European civilian airspace on the basis of one computer model, which it didn't check against reality. We already knew that the great volcano shut-down was based on a model, but we didn't know how little atmospheric sampling was performed to test the simulation against the atmosphere. It turns out only four test flights have been made to sample the composition of the cloud.
Matthias Ruete, the European Commission's transport chief, accused the Mystic Met of preferring virtual reality to evidence. "We have a model that runs on mathematical projections. It is probability rather than things happening," he said.
As a result the Met Office continued to issue projections of where it thought the ash cloud should be, but was unable to report its density and composition with confidence. These are critical vital factors an airline needs to know. European airlines sounded the alarm on Sunday, when they noticed that the satellite pictures didn't tally with the centre's output.
No volcano has ever had such intense media coverage - with newspapers even live-blogging the ash. But hardly anyone paused to check whether it was actually there. Only the BBC's Robert Peston, and a report on an environmental website Earth Times reported the airlines pointed out it was single sourced and a simulation.
The Met Office is involved because of its pioneering atmospheric dispersion model, now called NAME III, developed after Chernobyl in 1986. The Met's Volcanic Ash Advisory Centre is one of a network of 12, and advises Nats and the Civil Aviation Authority. It combines NAME with the Met's weather model, which is renowned for its accuracy [are you sure? - ed].
Instead of air sampling, the Met is obliged to fall back on Lidar, an optical sensing technology similar to radar but with severe limitations - the Met admits it can't tell the density of the ash.
Lidar results: less than comprehensive
Field testing from balloons or light propeller-driven craft would have filled the knowledge gap. UK civilian airspace shut down on Thursday morning. A four-hour test flight was made that evening, according to the Telegraph, but was inconclusive. Europeans had to provide their own sampling data on the composition and density.
The Met hadn't got back to us yesterday. Maybe we should lend them Vulture 1 - and a few balloons. ®
Yes, it's a model - short of populating the upper atmostphere with an array of sensors, that was always going to be the case.
Does it fall short of reality? Yes, it's a model.
Were "mistakes made" and will "lessons be learned"? Yes. It's a model.
Does it err heavily on the side of caution? Yes, because erring the other way involves probable loss of life (http://tinyurl.com/y4mmqqa)
I appreciate it may not be as accurate as everyone wants, but I'd be interested to know how accurate it needs to be before it's above criticism. Given the single event they've had to model from and the consequences if they get it wrong, this article sounds a little churlish to be honest.
Never let it be said the Reg let an atmospheric model pass without criticism.
Predict vs Measure ...
Ok, so who's volunteering to fly over the Atlantic , safe in the knowledge that ash hasn't fallen on Biggin Hill yet ?
The MO need to predict _in_advance_. As the joke goes, prediction is hard, especially of the future. And its easy to criticize if its not your prediction that causes hundreds of deaths.
Yes, measuring the density of the ash is a good thing. That requires specialised aircraft (adapted radar, particle protection on the engines, etc.) of which there aren't many. Aircraft that have flown through the ash (the Finnish air force) demonstrate how much damage it does.
Sure, some aircraft have flown at safe levels. They took a guess, and flying with the predictions of the Met services (and no passengers) landed safely. But tens of thousands of flights take place over Europe every day. How confident are you that, with a poorly tested model (not many volcanoes around here, you see), you can predict paths for aircraft so that not one in 50,000 flights gets hit ?
Its easy to claim over-zealous when its not you who has to make the decision. Meanwhile, airlines that decided it wasn't economically worth investing in dust-proofing their planes are looking at someone to sue to recoup their losses, and pick on the Met Office.
OK, we get it.
You don't like the anthropogenic climate change theory. You don't like institutions that appear to support it. You'll have a go at every opportunity, granted. But do yourself (and everyone else) a favour and PLEASE try to keep a bit of perspective; have a look at http://www.flightglobal.com/articles/2010/04/16/340727/pictures-finnish-f-18-engine-check-reveals-effects-of-volcanic.html . Now tell us all whether you'd be just fine with flying in a plane whose engines were in a similar state to those illustrated in that article. Didn't think so, because any other answer would indicate that you were stark slathering swivel-eyed windowlicking bugfuck nuts. The Met Office, with limited resources, issued advice that was extremely cautious, knowing that it would be used to determine whether flights carrying thousands of people might be put at risk. You know what? They still put a shitload more effort in and obtained more data than a publicity stunt with Willie Walsh did. NATS took their advice on board, and as noted above NATS took the decision, and quite rightly adopted a highly bcautious view also.