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Reducing the threat to aviation from airborne volcanic ash
From belgian newspaper "Libre Belgique" (20/04/2010)
It is beautiful, the birds sing. The quiet fills the skies above Europe hardly touched by the hubbub of this world: the planes can fly? The answers vary with particular airlines, testing support, requesting the reopening of the skies they get little by little.
But the debate rages about many unknowns. "States are working to get quantitative and qualitative observations about pollution and determine a degree of dangerousness is acceptable, says Mr Peter calmly Ghyoot Secretary General of the Belgian Cockpit Association. It is extremely difficult to determine because at the global level today, when there is presence of volcanic dust, air traffic is banned: it is the rule. In fact, there are no standards on the number of grams of ash per m3 air. It does not exist. And even if we knew a number concentrations in the air, it changes all the time. "
Alain Bernard, he rejoices in good volcanologist from the Free University of Brussels, to see the volcanic particles reach our region, is not optimistic: "The rules or criteria to tell the airlines," you can fly because the organic particles are below a certain threshold, it does not. It quoted figures, but we could not verify. Aeronautics grumbles because the aircraft can not fly, but at the same time, we never really tested what degree of problem with a dilute cloud of ash. There was absolutely no objective criteria to say "Here, the concentrations are such a level and you can fly. "There are research aircraft that made the tests, but nothing can make, because we did not test the tolerance of prolonged engine aircraft vis-à-vis volcanic ash. "
For his part, Gerald Ernst, a volcanologist at the University of Ghent, enraged. There are about ten years, he had already warned against this kind of phenomenon and its impact on air traffic. Specialist physical dispersion of explosive eruptions and volcanic ash, he helped set up an alert system in Iceland, but his research, like that of his colleagues, suffered a setback due to lack of resources and interest. He points the finger when the unpreparedness about this event: "We did not models that take into account the reality of the eruption. This model has been developed for the Chernobyl disaster and it does not consider the dynamics characteristic of the explosion. An eruption is not Chernobyl and the cloud is not dispersed passively by wind. And there is another aspect not taken into account: it's like a rash happens near a glacier, he yal'interaction between lava and ice, and it explodes. Very fine particles then form aggregates, pellets of ash and ice. These flakes falling so quickly. A good Part of gases and ash are discharged early, causing damage mainly in Iceland. But the problem is that the ice clouds the satellite and it causes uncertainty about the amount of aggregate, gas and ash that contains cloud "
And Gerald Ernst to suggest a quack occurred ten years ago with the current forecasting system: "In 2000, there was an explosion in Iceland. A cloud moved over the north. A research aircraft from NASA to then walked around 1 800 km north. According to the simulation made at the time, it should not be a cloud of ash. They are still spent in the middle and it cost four to five billion dollars repair the aircraft. It shows that the model was not developed and they use the same model today. There should have been laboratory experiments to calibrate the instruments. It has not been done: no funding. "
No doubt the magnitude of the economic mess will soon present standards and research on the subject.