Ash cloud models – overrated? A word on Post Normal Science by Dr. Jerome Ravetz

Figure 1. NAME prediction of the visible ash plume resulting from an eruption of Mount Hekla in Iceland on 16 February 2000.

“We sent ten Boeing 747 and Airbus 340 jets on transfer flights from Munich to Frankfurt,” Lufthansa spokesman Klaus Walther told the paper. The planes were moved in order to be in the most useful place once the ban is lifted, he explained.

“Our machines flew to a height of 24,000 feet, or around 8,000 metres. In Frankfurt the machines were examined by our technicians. They didn’t find the slightest scratch on the cockpit windscreens, on the outer skin nor in the engines.”

“The flight ban, which is completely based on computer calculations, is causing economic damage in the billions. This is why, for the future, we demand that dependable measurements must be available before a flight ban is imposed.”

Source: “the Local

At left: the model from the Met Office used to look at dispersion.

The Nuclear Accident Model (NAME) was originally developed after the nuclear accident in 1986 at Chernobyl, which highlighted the need for a capability to predict the spread and deposition of radioactive material released into the atmosphere. The model has continued to be developed and is now applied to a wide range of atmospheric pollution problems, ranging from emergency responses to daily air-quality forecasts.

Over the years, NAME has been applied to a number of atmospheric releases, including radioactive releases, the Kuwaiti oil fires, major industrial fires and chemical spills, and two major volcanic eruptions that occurred in Iceland. Both of these eruptions resulted in aircraft having to be re-routed to avoid potentially dangerous ash clouds. An example of the volcanic ash guidance provided to the aviation community is shown in Figure 1.

Source: NWP Gazette

Here is what Professor Jerom Ravetz of Oxford has to say about the issue (via email):

Interim contribution to the Post-Normal Science debate.

Considering the effects of the Icelandic volcano on air transport, we seem to have:

  • Facts Uncertain:  how thin must the dust be, for it to be safe enough for flying?
  • Values in Dispute:  Regulators wanting safety at all costs, others needing to get flying now.
  • Stakes High:  Crippling costs to industry, versus big risks to aircraft and people.
  • Decisions Urgent:  Every day the immediate costs mount, and the long-term costs grow.

Is this analysis an invitation to scientists to cheat?  Some of my critics would say so, and perhaps even some of my supporters as well!

h/t to  WUWT readers Nigel Brereton and Bernd Felsche


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The BBC reports that there is ‘zero tolerance’ on ash.
” ‘No tolerance’ rule for volcanic ash”:
[Quote] “Over the weekend, [our observations] have detected dust in the atmosphere and on the ground,” the Met Office said on its website.
“A research aircraft has recently encountered dust during its flight, albeit in fairly low concentrations.”
And, no matter how low the concentration, aviation authorities will not reinstate normal control over airspace while the ash cloud is still there.
A spokesperson from from Nats, the UK’s air traffic control authority, told BBC News that there was “no threshold” for concentrations at which volcanic ash was acceptable…Whether to open or close airspace is a decision for national aviation authorities, but all European nations abide by the rules set by ICAO, which recommends implementing a no-fly zone if volcanic ash is detectable in airspace. [end quote]
Theoretically, therefore, if we have sensitive enough detectors we will always find SOME volcanic ash everywhere in the world. If the only safe threshold is the threshold of detectability, we could soon see all aircraft banned at all times the world over as instrumentation and thus detectability improves. What utter stupidity. There surely has to be an ash density below which the risk to passenger aircraft is acceptable (say, commensurate with other normal hazards), for example 100ug per cubic metre continuously and 1mg per cubic metre for periods not exceeding one hour.
To adopt a ‘zero tolerance’ approach is like the Royal Society’s definition of ‘Dangerous Climate Change’ which is that there is no safe limit for climate change. All climate change , however miniscule is always ‘dangerous’:
“There is no such thing as ‘safe’ climate change…Any level of climate change will be dangerous”
Whilst it may be exceedingly difficult (or philosophically impossible) to define what is ’safe’, i.e. to define the boundary where it becomes ‘dangerous’, the problem is not solved by eliminating the category ’safe’ and therefore defining the whole universe of possibilities as ‘dangerous’. That neatly avoids the problem of having to define limits of acceptability and thresholds, but it is crass stupidity as well. Since climate has changed ever since the world began, by the Royal Society’s definition it will have always been dangerous.

Tero-Petri Ruoko

I don’t think that a REALLY short flight between Frankfurt to Munich really tells anything about the possible effects of the ash. And Germany isn’t even the country with most ash in the atmosphere. When lives can be in direct harm, better to be safe than sorry…


Better safe than sorry!!!


It’s all about the EU bureaucrats’ creeping control over their growing empire. This has been the perfect opportunity to see how the masses will react to being told when and where they can go. The results so far? EU 1 – plebs 0. Barely a peep from the sheep.


This only shows that Post Normal Science creator Jerome Ravetz had some shares of aviation companies in his portfolio.

Funny after posting the original post about the climategate files on Nov 19th
Tom Fuller and I went to see 2012.
At one point in the movie after the computer model misforecast the disaster, the head scientist came into the presidents office and said ” I was wrong”
I turned to Tom and asked ” Do you think anyone at CRU was ever so forthright?”
While not a luddite I think there is something disturbing about the way we turn decisions over to code. Which is really turning decisions over to programmers. Much as I would like to live in a world governed by “guys like me” It’s clear that if code drives our decisions processes, then that code must be open.


Over the weekend, I did see an article somewhere that mentioned “Met Office” and “computer models.”
And I thought,


So…PNS works as far as it does not touch my wallet.
Wrong PNS analysis Mr. Qliphot:
Facts Uncertain: how thin must the dust be, for it to be safe enough for flying?
Values in Dispute: PASSENGERS LIVES.
Stakes High: People in danger VERSUS crippling costs to INDUSTRY.
Decisions Urgent: Stop flights.
If you were a christian my advice would be: confess your sins to a priest and repent yourself.
As you are not, my advice to you is: Ask your Rabbi if your PNS agrees with the Torah.



I’m leaving it up here so that people know.
– Anthony
See below email exchange on Iceland volcano links to money and climate change. Seems like something is rotten in the state of Iceland!!!
—– Forwarded message ———-
From: Halldor Eggertsson
Date: Mon, Apr 19, 2010 at 8:11 PM
Subject: Fw: Latest from Iceland
Dear Ron,
The embargo is Midnight GMT 20th April. Please DO NOT publish prior! This is the biggest story our little paper is ever likely to break unless Bjork dies choking on her herrings!!!
Yeah, this is big story. Lot of people sweating here. I dont know how far this goes but lots of angles.
When this breaks its going to go crazy here so lets catch up when the dust settles (no pun intended heh!). We think there may be more to the climate change angle. The team is busy following up on that. It looks they made 2.6bn euros before the agencies caught on to them.
———- Forwarded message ———-
From: Ron Jedwood (Daily Mail – News Desk)
Date: Mon, Apr 19, 2010 at 7:25 PM
Subject: Fw: Iceland Volcano
To:; Halldor Eggerstsson (Reykjavik Bureau)
Hey Halldor,
Ron from London here, just got your mail. Your phone isnt answering. Must be getting a lot of traffic.
This is a big story! When are you running this? When can DM go? Unclear on the embargo.
Call when you can.
—– Forwarded Message —-
From: Hanfluss Janesbaer
To: Ron Jedwood (Daily Mail – News Desk)
CC: Halldor Eggerstsson (Reykjavik Bureau); Fjaldar Sigur Jonsson (Editor); Gunnar Skoleskar (Reykjavik Bureau)
Sent: Mon, 19 April, 2010 18:51:08
Subject: RE: Icelandic Volcano
Attention: Ron Jedwood – News Desk
FYI below. I received a bounce back message from your e-mail account. Please confirm receipt.
Hanfluss Janesbaer
Reykjavik: 20th April 2010
By Gunnar Skoleskar in Reykjavik and additional reporting from Hanfluss Janesbaer in Amsterdam
In a new twist to the ongoing eruption of Iceland’s Mount Ejafjallajoekull, spreading volcanic ash and dust across Europe and grounding thousands of flights, investigations into the activities of the energy consultancy, Icelandic Geothermal have revealed massive short selling of airline stocks, a leading airline organization has revealed.
The Amsterdam based Center for Airline Carbon Emissions (CACE) are investigating claims that Mr. Olaf Selfoss Olafson, founder of the Reykjavik (RSX) listed technology company, sold substantial holdings in several European airlines just weeks before the eruption.
Olafson’s company, a geo-thermal consultancy, developing technology to harness volcanic lava flows for water heating and steam turbine production has been linked to the eruption, following a several month undercover CACE investigation trailing the activities of Icelandic Geothermal, acquiring incriminating evidence on the way.
“We know that these guys were involved in the eruption” Helmut Schnellerflugzoeg, in charge of the CACE investigation told us. “Our team of analysts have been following the company’s activities after intelligence analysts intercepted their plans and contacted us.”
“They hired drilling machines to bore into the area where the volcano erupted, a couple of months ago, and we have video-footage of the lowering of large objects into the bore holes.”
When asked as to what these large objects could be, Schnellerflugzoeg was vague. “We have a good idea what it may be, and we know that it is a catalyst to volcanic eruptions,” he told reporters.
“The whole point was to help kill the airline industry and prove that global warming was in part due to aircraft emissions,” Schnellerflugzoeg said. “With aviation grounded, scientists would be able to gather evidence of a drop in mean temperatures and doctor the figures, showing perhaps as much as a 2 degrees centigrade drop.”
“It’s too early to say whether it may be linked to a wider conspiracy,” he continued, “but we are determined to get to the bottom of this exploding volcano.”
The fall-out could be sulphurous if there is any evidence linking the climate change lobby to the eruption, already reeling from criticism for providing information leading scientists to predict the disappearance of Himalayan glaciers by 2035. “If the climate change lobby is in any way linked to this volcanic eruption, it could be very damaging.” Professor David Sonnenbaum a climate specialist at the University of Berlin told us.
A spokesperson for Icelandic Geothermal denied any involvement in the eruption or the sale of any airline stocks. “We categorically deny any involvement in the eruption of the volcano,” Lars Grindavic Magnusson, CEO of the company told reporters at a press conference in Reykjavik on Monday.
Analysis of trades on European Stock Markets, including London, Paris and Frankfurt seems to indicate a substantial turn-over of stock in major airlines in the first week of April, a source close to the CACE investigation told the paper.
“There’s activity which potentially links the company to the eruption” Verloke Shomes, a senior investigator told our reporter in Amsterdam. “We are investigating a surge of buying activity on the markets on Friday, where a Cayman Islands holding company appears to have bought a lot of stock in publicly listed European carriers at bargain basement prices.”
The eruption has caused serious disruption to global air-traffic, grounding more than 17,000 flights daily and preventing transit across European airspace, potentially affecting more than 1.7 million travellers a day.
—–Original Message—–
From: Hanfluss Janesbaer (Amsterdam Bureau)
Sent: 19 April 2010 10:02
To: Reuters (London Desk); AFP (Paris Desk); IHT (Brussels Desk); Associated Press (London Desk); The Times (London Desk); The Daily Telegraph (London); Bild (Editor – Berlin); Le Monde (Paris Desk); Frankfurter Allgemeine (Frankfurt Desk); Editor (El Mundo – Madrid) La Republicca (Rome Desk); IHT (New York Desk); Editor (Washington Post); Editor (New York Times); News Desk (Daily Mail); Editor (Sydney Morning Post); Editor (LA Times) Editor (Straits Times); Editor (China Daily); Editor (South China Morning Post); Editor (Shanghai Daily); Editor (Khaleej Times – Dubai); Editor (Hindustan Times – New Delhi); Editor (Times of India – New Delhi); Editor (Indian Express – New Delhi); Editor (The Bangladesh Today); Editor (Dawn – Karachi); Editor (Kathmandu Post); Editor (Cape Times – South Africa); Editor (Jornal do Brazil); Editor (Buenos Aires Herald); Editor (Ashai Shimbum-Tokyo)
Subject: Re: Icelandic Volcano
All. Attached is our piece we have just put out on the Icelandic Volcano, which you may run Midnight GMT 20th April.
Hanfluss Janesbaer
> This message
> and any attachment are confidential and may be privileged or otherwise protected from disclosure.
> If you are not the intended recipient, please telephone or email the sender and delete this message and any
> attachment from your system. If you are not the intended recipient you must not copy this message or attachment
> or disclose the contents to any other person.
—–Original Message—–
From: Fjaldar Sigur Jonsson (Editor)
Sent: 13 April 2010 16:37
To: Hanfluss Janesbaer (Amsterdam Bureau); Gunnar Skoleskar (Reykjavik Bureau); Jon Smorgesbord Stefanson (Reykjavik Bureau); Kristabjorg Soren Kjellner (Reykjavik Bureau); Hjalmar Ericson (London Bureau);
Subject: Re: Final Copy
Dear team,
Attached is a piece which we are going to press with in tomorrow’s edition.
Gunnar, Hanfluss, make sure you double check the copy for any errors and double check your notes for the quotes.
Some fantastic undercover reporting here. You get your cases of Vodka for this one.
Hanfluss – Expense the accommodation and keep your meal receipts.
We’ll syndicate it with the agencies next week.
—–Original Message—–
From: Hanfluss Janesbaer (Amsterdam Bureau)
Sent: 13 April 2010 16:37
To: Fjaldar Sigur Jonsson (Editor); Jon Smorgesbord Stefanson (Reykjavik Bureau); Kristabjorg Soren Kjellner (Reykjavik Bureau); Hjalmar Ericson (London Bureau);
Cc: Gunnar Skoleskar (Reykjavik Bureau)
Subject: Re: Final Copy
Eitt tungumál er aldrei nóg. Attached is the final draft in English. Good to go when you’ve checked the facts.
Gunnar – you’ve got anything to add from Olafson?
Looks like I’m going to be stuck here in Amsterdam for some time. Hvar er klósettið?
—–Original Message—–
From: Fjaldar Sigur Jonsson (Editor)
Sent: 12 April 2010 09:46
To: Hanfluss Janesbaer (Amsterdam Bureau); Jon Smorgesbord Stefanson (Reykjavik Bureau); Kristabjorg Soren Kjellner (Reykjavik Bureau); Hjalmar Ericson (London Bureau);
Cc: Gunnar Skoleskar (Reykjavik Bureau)
Subject: Re: Final Copy
H – Gætirðu skrifað þetta niður? Any more?
G – Langt síðan við höfum sést. Speak with Olafson – he’s hiding something, I can smell it. Svifnökkvinn minn er fullur af álum
Krista – Lawyers?
What a story! Náið í lögregluna!


I’m leaving it up here so that people know.
– Anthony


All of this has been based on the MET’s computer models????,1518,689735,00.html
‘Air Berlin CEO Joachim Hunold criticized the fact that the results of test flights had no influence on the decision of the air traffic control authorities as to whether to reopen airspace in countries across Europe. “In Germany, no one has even sent up a weather balloon to measure if volcanic ash is in the air, and if so, how much,” Hunold told the Süddeutsche Zeitung newspaper.’


Is this analysis an invitation to scientists to cheat?
It’s an invitation for them to get out of the way and let people with real-world experience handle the issue. Test flights have been safely concluded, some have recommended daytime flying as pilots can see and avoid ash clouds… Those who actually do the flying know they can be flying, those sitting behind computer screens looking at model outputs say they can’t.
Reality trumps modeling. Experience trumps theory. It’s a reoccurring theme, better get used to it.

The density of ash various tremendously spatially and temporally, with eruption parameters and wind changing constantly. The fact that a few cherry picked test flights made it though safely isn’t particularly interesting.
Challenger O-Rings worked fine, until they didn’t. The computer simulations are the best tool available.

JIm (08:18:41) :
Met Office computer models, like other weather models, work fine for a few days into the future.

Hu Duck Xing

I’m inclined to side with “better safe, than sorry.” From the AP;
“BRUSSELS — A senior Western diplomat says several NATO F-16 fighters suffered engine damage after flying through the volcanic ash cloud covering large parts of Europe.
The official declined to provide more details on the military flights, except to say that glasslike deposits were found inside the planes’ engines after they patroled over European airspace.
Last week, two Finnish Air Force F-18 fighter-bombers suffered similar damage while flying through the ash plume that has paralyzed air traffic over much of Europe. Both landed safely, but their jet engines will require expensive overhauls.”


“Oh, models, models, how many crimes have been commited in thy name”


More than any other country, Britain has turned into the nanny-state. If the airlines and the passengers agree to take their chances on a flight, then fly they should. Life is full of risks and those that are “better safe than sorry” are a sorry, cramped, gray lot indeed.
“Those who would give up Essential Liberty to purchase a little Temporary Safety, deserve neither Liberty nor Safety.” B. Franklin

Gareth Phillips

Aircraft have been damaged. The BBC reported that “A build-up of glass has been found in the engine of a Nato fighter jet in Europe, a US official says”
Now, ask yourself, would you risk it? are you feeling lucky? Or should we play safe?


If they need to fly then let them send a small scout aircraft ahead of the larger plane. All it does is monitor the ash etc and send info to the large plane following. If it gets too thick then the small plane changes direction and the large one follows to an altitude without ash before it even hits the thick stuff.
There are alternatives but shutting everything down in the name of safety first seems to be the default reaction.


Nothing is better than real experimentation… I mean, we are not talking about a sand storm here!

Stephen Wilde

I think I’ll stay in bed for the rest of my life.
It’s just too dangerous to get up.
Better safe than sorry 🙂


You know what? You who are parroting the “precautionary principle”: get a clue.
Atmospheric ash is a measurable risk to aircraft. So are storms, turbulence, quality of fuel, loading, etc. etc. etc. It is not very intelligent to believe that zero-ash is the only way to fly.
It should be the decision of the airlines in this case, and if it requires more frequent engine and window maintenance, then so be it.


No scratches… great.
But how about fused ash “glass” microcoatings on the high temperature power turbine blades and combustors?
This has been reported as THE mechanism of major damage on military jets used in similar testing in Europe, not erosion.

p.g.sharrow "PG"

Bureaucrats will always destroy the industry they manage. In a bureaucracy you advance by saying no, never by by allowing things to move forward. There is a “policy” of ,When in doubt say NO, you don’t need judgment. Normal people live with risk.

Tom in Florida

The “no tolerance” rule is just a way to prevent someone from sticking their neck out and being blamed. If no one has to make a decision on what is safe and what isn’t, then no one can be sued for being wrong.

Pat Moffitt

Tero-Petri Ruoko (08:06:36) :
There are always second order consequences. 9/11 and the fear it produced pushed large numbers of passengers away from airplanes and into their cars. Car travel (per mile) mortality rates are far greater than is air travel and death rates rose dramatically in the months following 9/11.
Risks are rarely avoided they are transferred . Its at the heart of the precautionary principle fallacy– you must look at all risks not just the ones you choose to fear.

Alan the Brit

Yet again we see computer models that cannot get the weather right months in advance, claim that they can predict climate 100 years from now, & now tell uss where a dust cloud is or isn’t going to be!
There just has to be a safe upper & lower limit of volcanic ash definition as we in the construction industry have been operate a trigger system with the Interdepartrmental Committee on the Redevlopment of Contaminated Land guidance!

Ryan C

Funny, on the NationalPost today there is an article about how the EU is planning on using taxpayers money to send poor people on vacations. They say that vacationing is a `human right`. Where do they keep finding all of these extra tax dollars..


I thought that Global Warming science has proven that computer models are reality, not that reality is reality…


I wonder if the 10 747s and A340s were a sort of sacrifice to the volcano in lieu of the traditional virgins, as they couldn’t find any on short notice?
Clearly it is the ‘wrong sort of ash’?

matt v.

Iceland major volcanic eruptions since 800AD
800 -1[0]
900 -2[2]
TOTAL -35[19]
The analysis shows that there were fewer eruptions during the MWP and the current warm period and more eruptions during the LITTLE ICE AGE.[1500-1800 ]
KATLA is the dominant eruption [50% of all eruptions ] and historically overdue .Erupts typically 2-3 times a century but no eruption since 1918 or for 92 years. However it was also quiet 934-1210 AD or during much of the last warm period [MWP]
If Katla does erupt it is likely next year after current eruption of Eyjafjallajokul ends. The latter may continue on and then in a more subdued way and then active again type of cycle for a year. This was the pattern 1821-1823. I cannot comment on the ash issue or their models

Henry chance

If the models are acceptible, which model predicted the eruption? But the models failed?
What percent of the time should we go by computer models and simulation and what percent of the time do models say we should ignore the models?


@ScientistForTruth (08:05:13) :
I suggest you leave the job of aircraft safety with those who know what they are talking about!!!


Pops (08:09:18) : “Barely a peep from the sheep.”
I don’t think that contemptuous language likes this is going to help us to convince people of the strength of skeptic arguments. Most of us can be unaware and even gullible sometimes when it comes to questions outside of any expertise we may have. Slurring people who have different views from oneself is largely the domain of Real Climate and the like, lets keep it that way as it just alienates most people.
In this instance, most people have barely been exposed to any evidence that some current flying bans may be unreasonable. The only such reports I’ve seen in the media suggesting this are quoting the airlines. Airlines, to say the least, have not always put passenger safety first when money is at stake so the general public would not be unwise to treat their views with some suspicion, even if they might happen to be right in this instance.

John Blake

Aristotle described motion as due to mechanical “impetus”: Released from archers’ bows, arrows fly straight, as aimed, until their impetus is exhausted, whereupon (says Aristotle) they cease moving forward and fall directly to the ground.
No-one in his right mind could ever justify such nonsense by observation; yet over some 1,800 years, to Galileo’s time, Aristotle’s physics ruled Scholastic teachings unopposed. “Post-normal Science” is just such an atavistic phenomenon, an anti-empirical/observational approach akin to sad-sack literary critics’ embrace of Derrida’s “deconstruction”, which elevates PCBS academics over any vestige of creative imagination.
Just so, staggeringly arrogant and malfeasant bureaucratic authorities actively oppose real-world constraints on power-hungry authority, which invariably acts only in the negative– never a constructive policy of monitoring activities within risk parameters, but always the playground-level approach of equating skinned knees as quadriplagic paralysis. Needless to say, reigning administrative sycophants have nothing of their own at stake… one smidgen of impact on their rent-seeking operations would instantly require ordering airlines to take flight regardless of contingent consequences.
Big Government is the Enemy of the People. Foot on neck, airlines and passengers await the fatal chop.

Craig Goodrich

Just a minute. The Brits shut down Heathrow on the basis of a model from the Met Office?? Where is Piers Corbyn when you need him?

L Nettles

As a rule of thumb, “Zero Tolerance” can usually be substituted by “stupid” without a loss of meaning

“Facts Uncertain: how thin must the dust be, for it to be safe enough for flying?”
Since aircraft have been flying around volcanoes for decades, not to have threshhold levels (say, 100ug per cbm continuous; 1mg per cbm not exceeding one hour; 3 mg per cbm not exceeding 2 minutes etc) is unforgivable. This is therefore simply an ‘own goal’. It is negligence by the regulators (not only financial regulators guilty of this, then).
“Values in Dispute: Regulators wanting safety at all costs, others needing to get flying now.”
Give over – passengers want safety as well. The problem is conflated with the ‘facts uncertain’, since if it ‘safe enough for flying’, then that’s going to satisfy all parties.
“Stakes High: Crippling costs to industry, versus big risks to aircraft and people.
Decisions Urgent: Every day the immediate costs mount, and the long-term costs grow.”
Only because of the paralysis due to the ‘facts uncertain’, which should never have been allowed to happen. This is a self-generated problem. There was, after all, an International Symposium on Volcanic Ash and Aircraft Safety, in Seattle in 1991 NEARLY 20 YEARS AGO, see here for Proceedings:
The paper by Przedpelski and Casadevall states:
“The greatest threat to aircraft and engines is presented by “new” clouds (within hours of eruption) that contain large concentrations of ash particles…The ash particle size distribution in volcanic eruption clouds should be documented. In addition, engine and (or) combustor tests should be sponsored by the Federal Aviation Administration (FAA) to establish threshold values for “safe” levels of ash concentration and the “safe” range of combustor temperature. This information, combined with updated dispersion and theoretical fallout models (and with improved cloud tracking) can establish when an ash cloud ceases to be a flight hazard. These efforts will enhance aviation safety and reduce air traffic delays resulting from volcanic activity.”
Let’s face it, the regulatory authorities and the engine manufacturers have had decades to perform actually very simple and controllable experiments, and so enact the recommendations from the international symposium. I have no idea whether they did so – it appears that they focused on detection and avoidance rather than thresholds, and so we have the unacceptable situation we have today. The same type of thing occurred when London had an unexpected snowfall in 2009: not a single London bus ran that day. Strangely enough, this sort of invocation of the precautionary principle (if in doubt do nothing or shut everything down) is nothing more than a cop-out, and it is interesting to note that the more businesses are required to do ‘risk assessments’ the more the precautionary principle is employed, not the less. Risk assessment today seems to be more a process of risk identification and avoidance, giving more and more excuse to shut activities down rather than properly manage the risks.
If the authorities have not actually performed the relevant experiments to determine what ash density thresholds are commensurate with acceptable aviation risk (say, similar to other risks) – experiments that CAN be done in the lab on multiple engines in controlled conditions – and ESPECAILLY after that International Symposium 19 years ago, then they have saddled the world with the problem we are facing today. The fact that ‘scientists’ seem to want to avoid doing properly conducted experiments with copious real world observations withrobust physics is a drift back to the Aristotelian method where dogma, theory and dialectic took the place a proper evaluation of the real world. This is where we have arrived at in climate science, to a large degree.
I conclude that this is NOT a scenario suitable for Post Normal Science, but a complete fiasco that could have been avoided by the application of proper scientific method.

Indeed – here’s the interesting thing. Most of the EU’s airspace has been closed down on the say so of the Met’s model. Which some in the EU commission are starting to question:
“The science behind the model we are running at the moment is based on certain assumptions where we do not have clear scientific evidence. We don’t even know what density the cloud should be in order to affect jet … engines. We have a model that runs on mathematical projections.” – EU Commissoner Matthias Ruete

Bernd Felsche

Short flights inconclusive, eh? currently shows whatappears to be a test flight from Airbus Industrie (callsign F922),an A340-642, with the track first originating around Paris. The aircraft flew athigh latitude to the Germanborder and turned North until it was well over the sea and about level with the Danish border, whereup it did a U-Turn while losing altitude. The crossed the coast and headed towardsHamburg which it “buzzed” at less than 3000 m (10,000 ft), flying a loop around before turning towards Berlin. But before it was about half-way there, it turned NE, climbing gradually until it got near the coast before it again turned at the Polish border, still climbing.
But it’s not landed in Berlin. (Flights have been taking off from there all day.) F922 is currently on a track (heading) of 282 — no, now 227 — at FL410.
A B747 cargo flight left Amsterdam a while ago, now at FL290 on a track of 156.
There’s been activity like that since dawn.


JIm (08:18:41) :
Over the weekend, I did see an article somewhere that mentioned “Met Office” and “computer models.”
And I thought,

I saw a similar arcticle, unfortunately it’s now behind a subscription paywall. In it a spokesperson from Lufthansa said that all the aircraft groundings are solely based on computer simulations of the ash cloud from a volcanic ash center in Southern England, which passes its findings to the Met Office, which distributes it to the national authorities in Europe. Not a single weatherbaloon was sent up to actually measure if the ash is even there over Germany, he said.
Now I thought also that this sounds familiar:
– Far reaching and very expensive decisions based solely on computer models
– No independent measurement of real world data
– Ignoring real world data from test flights
– Met Office involved
Where have I heard that before?

Lionell Griffith

Tell the decision makers who are trying to duck the responsibility for the consequences of their decisions the following:
1. You picked the software program
2. You picked the people to run the program
3. You picked the people who selected the data for the program to use
4. You made the decision to rely on the computer output
5. A computer can do only what it is told to do
6. You are responsible for the consequences, not the computer
Unfortunately, this is asking them to deal with reason, reality, and logic, Such things don’t seem to be the concern of the “decision” makers. They have the power and they will use it no matter what. That reality does not behave according to their decisions makes, in their opinion, reality wrong. The only thing that matters to them is that the rest of us have to beg “Mother may I?” before we can act.
Question: why have we allowed the inmates to run the asylum?
Question: why have we given them the tools to force their psychosis upon the rest of us?
Question: why do we accept the situation without doing something about it?

The response to the issue of airborne ash highlights the enormous loss of scientific/ engineering capability at the disposal of the UK government. At one time the resources of the National Gas Turbine Establishment and the Royal Aircraft Establishment would have been available, these institutions have been either closed or privatised. A comperehensive test and analysis program would have been initiated invoving extensive flight and ground test. In addition computer models would have been calibrated and boundary conditions determined by the use of REAL FLIGHT AND GROUND TEST MEASUREMENTS.


This will be a grand lesson in who’s got the beef in European international politics.
1. The traveling public have interests in getting where they want
or have to go, getting there affordably, and getting there safely.
2. The airlines have a quadruple interest in getting them there, getting them there safely, getting them there at a profit per seat, and maintaining their overall corporate revenue streams.
3. The EU in conjunction with several members’ nation air
administrations want no additional risks accepted by airline
companies ro get their passengers from one place to another.
They want to enforce their ability to restrict travel under the
terms of the EU charter.
4. The investors in airline companies, including those nations running their own airlines, want to stay in business while breaking even or turning a profit.
5. The insurance companies covering airline companies for risks to passengers, or assets like planes and ground facilities, and/or
unavoidable revenue or profit loss due to involuntary situations
like being grounded for “dust”.
6. The re-insurance companies that cover the insurers in case a
whopping claim can’t be immediately covered by the regular
insurance firms.
7. The individual nations who have travelers that conduct their
business on an international level and keep their respective
national economies pumping.
8. Investors and the investment community in general who hate
falling profits, stressed insurers and re-insurers, impediments
to economic expansion, and national/regional economies made
sluggish by some unnecessary government impediment.
I’m betting on No. 6, the re-insurers having the most influence.
I doubt the EU will continue to have unfettered dominion in
situations like the Icelandic eruptions in the future.
It looks like both the politics and the science have yet to be


Link Between Solar Activity and the UK’s Cold Winters
with the obligatory disclaimer that this is minor trend within the overall scheme of AGW. How about this jarring quote:
“This year’s winter in the UK has been the 14th coldest in the last 160 years and yet the global average temperature for the same period has been the 5th highest. We have discovered that this kind of anomaly is significantly more common when solar activity is low.”
There you have it. Only the UK is affected, you see. A special place indeed, it must be.

This event is not a good advertisment for using “models”.


Here is a report from the NASA DC8 encounter with volcanic ash in 2000. It details the insidious nature of the ash – no strong indication to the pilots/crew that they were in the plume, and no readily apparent damage after the flight, but after the engines were disassembled, damage to the engines was discovered, which would have reduced the engine lifetime to 100hrs.
Definitely not fun stuff…

Bernd Felsche

Short flights inconclusive, eh? currently shows whatappears to be a test flight from Airbus Industrie (callsign F922),an A340-642, with the track first originating around Paris. The aircraft flew athigh latitude to the Germanborder and turned North until it was well over the sea and about level with the Danish border, whereup it did a U-Turn while losing altitude. The crossed the coast and headed towardsHamburg which it “buzzed” at less than 3000 m (10,000 ft), flying a loop around before turning towards Berlin. But before it was about half-way there, it turned NE, climbing gradually until it got near the coast before it again turned at the Polish border, still climbing.
But it’s not landed in Berlin. (Flights have been taking off from there all day.) F922 is currently on a track (heading) of 282 — no, now 201 — at FL410.
A B747 cargo flight left Amsterdam a while ago, now at FL290 on a track of 156.
There’s been activity like that since dawn.

“No threshold” is a threshold, in this case the threshold is greater than zero! ASH_LEVEL > 0.
I love double speak.
Maybe the fuss over basing the decision on a “model” rather than something as strange as “measurement” will sink in with people finally.


Hasn’t been much comment on Ravetz, per se. Is this proof of the validity of “Post Normal Science?” I do not see how. The “extended peer group” here would seem to be the travelers and airlines, wondering when it will be safe to fly again. That is not a question that depends on science. It is a question that depends on technology. Instead of looking to scientists for answers to the question, we should be looking to engineers. This is question more like whether it is safe to cross a bridge that has been stressed or damaged by an earthquake. I’ll ask an engineer the answer to that question, not a scientist.
Sorry, Dr. Ravetz. No go.

I would like to know if these models predicted that the ash cloud would end up in Canada. If not, they are truley usless.