As a follow up to our 4/19 story about ash cloud modeling:
Ash cloud models – overrated? A word on Post Normal Science by Dr. Jerome Ravetz
I offer below a compendium of articles from Benny’ Pieser’s CCNET and GWPF of the UK
Above:
The Met Office has been blamed for triggering the “unnecessary” six-day closure of British airspace which has cost airlines, passengers and the economy more than £1.5 billion.–The Telegraph 19 April, 2010
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Global airlines have lost about $1.7bn of revenue as a result of the disruptions caused by the Icelandic volcanic eruption, a body has said. Giovanni Bisignani, chief executive of IATA, criticised governments for the haste with which they closed airspace, and called on them to provide compensation to the airlines. “Airspace was being closed based on theoretical models, not on facts. Test flights by our members showed that the models were wrong.” —BBC, 21 April 2010
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We are becoming a risk-averse society and that is dangerous. You cannot run a national economy on the precautionary principle; indeed, the sound position is to embrace as much risk as possible. Societies that embrace risk, such as the United States and recently the UK, tend to thrive, while those that seek to minimise risk, such as Britain during the 1970s, tend to wither. Financial capital is now fleeing Britain, heading to the Far East. A long queue of companies is chasing the money, including our own Prudential, which is floating a business on the Chinese stock market. The true venturers are over there, not in Britain. —The Times, 21 April 2010
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Rational decisions have to be taken on the basis of some empirical understanding of the risks involved, and on the balance between risk and reward (or the cost of avoiding risk). Exposing the nonsense and muddle of the so-called precautionary principle is an essential part of the GWPF’s declared mission ‘to bring reason, integrity and balance to a climate debate that has become seriously unbalanced, irrationally alarmist, and all too often depressingly intolerant’. If the argument now raging over the policy response to the volcanic ash clouds assists in achieving this, it will demonstrate that ash clouds, too, have a silver lining. —The Global Warming Policy Foundation, 20 April 2010
Phil. (12:47:43) :
Al Gored (12:04:53) :
I love this story.
Models versus reality with enough cost and consequences to hopefully make people think.
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So do you think that they should shut down the Alaska VAAC after all it only gives advisories based on computer models?
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The point is that because this cost so much money and grief this episode does make people think about the very obvious difference between models and reality. You are thinking about it.
The problem has been that too many people don’t understand the difference at all. In the AGW debate some people actually take model projections and predictions as some kind of concrete ‘proof’ or reality when time and again they have proven to live up to their basic ‘garbage in, garbage out’ premise.
And as I am sure you know, one can tweak the inputs and assumptions to make a model show anything you want it to.
Models are often wrong but reality never is.
Echoing Steve and some others, there is nothing inherently wrong about using computer models for forecasting ash dispersion. Over the short-term, these have a good track record – the parameters being modelled are limited and, unlike long-term climate models, are falsifiable. Thus, there have been several upgrades, based on real data from actual eruptions, which makes the model a fairly useful tool.
However, from what I can ascertain, the predictions degrade with distance and time, and after about three days there are considerable uncertainties, both as to location and to particle density. Thus, it is imperative to supplement the modelling with physical measurements – using ground sensors and airborne sampling.
This is where the UK (and the rest of Europe) seems to have been caught out. There is a serious shortage of suitably equipped and available aircraft for ash sampling, which meant that the first sampling flight by a suitable research aircraft (i.e., other than the “noddy” Do 228) was not carried out until Monday in UK airspace. It is no coincidence that, by Tuesday, the ban was lifted.
It seems to me, therefore, that the essential flaw is that the ICAO contingency plan puts too much emphasis on modelling, and does not insist on confirmation from physical measurement. I have my suspicions that this omission is due to a reluctance to commit member states to additional monitoring costs.
I have explored these issues here:
http://eureferendum.blogspot.com/2010/04/struggling.html
Anthony -I think you’re missing the point.
The Met Office is tasked with providing predictions of where ash concentrations will be above engine safety tolerances. It is not the Met Office’s task to decide how much ash an airliner engine can ingest before damage occurs -that lies with the manufacturers.
At the start of this crisis, the engine tolerances as defined by the aircraft engine manufacturers was “zero”. i.e. the aircraft manufacturers said that if there is any ash at all, then it is not safe to fly.
The Met Office did a good job at showing the areas containing ash -even though many of those areas would have very low concentrations. It would have been completely inappropriate for the Met Office to have used any threshold other than that defined by the manufacturers (they are the experts in aircraft engines).
When the manufacturers eventually came up with the more realistic tolerence value of 0.002g/m3 then the no-fly areas shrank dramatically at the planes could start flying again.
e.g. see the red zones in the new maps:
http://newsimg.bbc.co.uk/media/images/47685000/gif/_47685766_forecast_21st_1229_4663.gif
You haven’t shown any evidence to indicate that the model ash concentration predictions were inaccurate. The problem was with a (possibly) over-cautious engine tolerance threshold as defined by the aircraft engine manufacturers.
there are so many UAVs. they go from a few pounds to 1 ton.
http://www.globalsecurity.org/intell/systems/uav.htm
Almost all of them have excellent cameras. Why could they not use those for figuring out where the clouds are, a simple jury-rigged, filter, mounted on those babies could get you the concentration, composition and size diistribution of the ash. a an army of thousand of those puppies would have been cheaper than 250Million Dollars a day.
Anu (11:45:59) :
i like your sarcasm. but i don’t think anybody on this site was that cavalier about “lives”. All, most of the “should have flown” crowd is saying, why are they making such momentous decisions on some Model”, that does not seem to have been validated with real-life data. That is a legitimate beef
The only reason a pilot flies through an area of thunderstorms is because they have radar to show them a reasonably safe path through the storms.
If icing is forecast, they have de-icing equipment that can melt/shed accumulated ice, up to a certain point.
Ash could be enveloped by clouds, being invisible to pilot and satellite. They have no “de-ashing” equipment.
With the amount of air traffic over europe, you can’t have 747’s etc. running around “willy nilly”, avoiding areas of concern. That’s not how air traffic control works in crowded airspace.
As i said earlier, quite the dilemma.
nandheeswaran jothi (13:35:40) You must admit that the real (fashion) models are by far better.
I GOT IT! Those models are anorexic!!
First, it’s unlikely — I dare say impossible — that an airplane would crash from flying through light (undetectable by satellite) ash. (There have been no crashes from flying through even the heart of heavy plumes, despite some flame-outs.) The worst would have been a need for earlier maintenance on the engine. That trade-off should be the airline’s call to make.
Second, I don’t think it was necessary to prohibit flights over areas far away from the potential cloud, like Spain, at such an early date as was done. Whoever was responsible was exhibiting hall monitor behavior (jack-in-office officiousness).
Third, the real scandal was the failure to do pro-active and coordinated contingency planning, despite having a month’s advance warning. Hopefully, that planning will now occur.
Fourth, an ash-cloud-monitoring drone/UAV should be designed that can fly through ash (maybe using the old V1 bladeless design) and report on its characteristics in real time, and fleets of them should be deployed in volcanic hotspots on heavily traveled airline routes. The cost/benefit ratio would be attractive, even if the project costs over 100 million $.
“stevengoddard (10:33:04) :
The Met Office models are actually quite good at modeling atmospheric circulation over a period of a few days.”
This winter they failed to predict several major storms only a few days in advance, as Andrew Neil pointed out in his interview of John Hirst on January 6. That’s why the BBC has seriously and publicly considered no longer using the Met Office forcasts.
PS: Ash-testing drones could take off from Iceland and land downwind in Scotland, Scandinavia, SE England, Germany, etc., etc. There they’d be refueled and head back to Iceland (or wherever they were needed most). Their range wouldn’t be cut in half by a need to return to a home base, IOW.
My laymans experience with ash clouds from NZ volcanoes (e.g. from Mt Ruapehu) is that the airlines keep an eye on the actual ash clouds and taking into account the best available meteorological information they simply fly around them or over them. No big deal really. They only stop flying if the shit really does hit the fan and flights are cancelled only in the immediately affected area.
This whole Icelandic ash thing seems like a massive over-reaction from where I sit.
“Ian (13:26:51) :
Many posting here have indicated “Better safe than sorry” a sentiment with which I agree. But by the same token, shouldn’t that sentiment apply to the models that suggest human produced CO2 is largely responsible for climate change? And if not, why not?”
Once it was proven that the ash did not produce as much of a risk as guessed, the planes flew again. Facts trumped theory. The difference between that and AGW is this: Long term warmist predictions have been consistently wrong for the last 30 years and they never, ever, ever let facts get in the way. If anything, Dr. James Hansen’s latest prediction about sea level was more fabulous than his previous predictions and also, so far, more wrong.
AGW alarmism is impervious to facts, and thus more like a cult. Man of course has some effect on weather, but so far, the effect is barely detectable. The long-term trends have been the same as since the LIA.
Before computer models they would have to have sent up piston engine aircraft (or UAVs) with beefed up air cleaners. And collected real data in real time, you know like the old scientific way.
Guys, in my days – admittedly a long time ago – we (the USAF) had air sampling capability. I was on a sampling Recon crew for several years. We sampled for things other than volcanic ash, but I fail to see a significant difference. Particulates in the air can easily be sampled. And once you know just what is up there, and exactly where it is, short term modeling should be a great tool.
I suspect that since atmospheric nuclear testing is a thing of he past, so are these capabilities. Anthony is absolutely on-target when rating observations as more accurate than models.
Maybe a consortium of airlines finance sampling, and a UAV may well be the way to do it!
The Met Office Forecast accuracy interval has been increasing at about 0.5 days per decade.
http://www.metoffice.gov.uk/corporate/verification/forecast.html
Reactions to the few days of flight restrictions are wildly exaggerated, and comparing all this with the carnivalesque nonsense of the CAGW industry is rather silly. That the airlines lost money for a few days is unfortunate, but really, I can’t see what the great wise alternatives should have been, on short notice and with little data to go by. The situation of having a large amount of volcanic ash blowing steadily toward Europe was totally unprecedented. The fact that this ash poses significant risk to aircraft is well known. Nobody knew exactly how the ash was dispersing. Airplanes are not equipped with ash radars, which means pilots could fly into it without even noticing it.
What else could they have done? Wait until something happens? It’s more than understandable that the people or entities in charge of making those decisions must not have been too thrilled about adopting a “let’s keep flying and see what happens” kind of strategy, if only for the sake of covering their own behinds. That’s perfectly understandable to me, and has nothing to do with the army of psudoscientific louts and the future carbon barons that fund them to keep peddling the catastrophic “climate change” snakeoil.
So the airlines lost some money for a few days. Well – not the end of the world, is it? I am sure they’ll be just fine, or be bailed out when and if necessary.
“”” len (10:11:15) :
wish there was an edit:
yes the models were probably too “conservative” from a safety point of view, but i’d rather have safe + all the airlines all got a free cover your *** excuse. “””
Well we know it is possible to build an absolutely safe aeroplane. Where it gets tricky is if you also want flight with your absolutely safe aeroplane; we are not at that point in the technology yet.
Rob R (14:29:26) :
My laymans experience with ash clouds from NZ volcanoes (e.g. from Mt Ruapehu) is that the airlines keep an eye on the actual ash clouds and taking into account the best available meteorological information they simply fly around them or over them. No big deal really. They only stop flying if the shit really does hit the fan and flights are cancelled only in the immediately affected area.
Just like the London VAAC the Wellington VAAC covers the airspace around NZ and issues SIGMETS and Volcanic Ash Advisories, according to them:
“Volcanic ash constitutes a serious threat to aircraft operations primarily due to the effect of the corrosive gases and abrasive particles on aircraft engines and airframe. In addition to loss of engine performance or even flameout, ash effects may include instrument and radio failure, visibility problems and damage to other external flying components as well as contamination of the aircraft interior.
Such potentially serious and expensive damage is best prevented by avoiding flying through ash altogether. Over recent years, improvements in observation networks, satellite technology, computer modelling and our increased understanding of the phenomena have led to improved volcanic ash forecasting methods.”
nandheeswaran jothi (14:04:15) :
Anu (11:45:59) :
i like your sarcasm. but i don’t think anybody on this site was that cavalier about “lives”. All, most of the “should have flown” crowd is saying, why are they making such momentous decisions on some Model”, that does not seem to have been validated with real-life data. That is a legitimate beef
No it’s not a legitimate beef, it’s rubbish based on a totally false premise! The models are tested against real-life data and proved to be very reliable.
REPLY: Nobody is suggesting pilots fly through the visible ash, like thunderstorms, they can simply avoid it if they know where it is. You don’t need a model to show you where it is if you can observe it. You don’t need to ground a whole continent if you can follow the plume. -A
But that’s the point Anthony, you can’t see them, the best information on the 3-D location of the plume are the model reports. That’s why IATA initiated the VAAC system, which the London VAAC is part of. If it were as simple as VFR rules, approximately stay out of clouds which you can see it would be easy (except at night of course). We’re not talking about thick black clouds like the ones emerging from the volcano.
Phil,
Some models are good, and some are not. GCMs are NG: click
Time to add another 16K of memory to the Altair.
I’ll bet that most people that fly a lot, never knew that when coming in their destination, the pilots main concern was to get the ice off the wings and control surfaces, picked up coming through the clouds.
Super-cooled water droplets freezing on contact.
The engineers made an app., for that.
bemused (13:57:18) :
“You haven’t shown any evidence to indicate that the model ash concentration predictions were inaccurate. The problem was with a (possibly) over-cautious engine tolerance threshold as defined by the aircraft engine manufacturers.”
There is no evidence I have seen that say the predictions were accurate either.