Scientific advice and evidence in emergencies - Science and Technology Committee Contents

Examination of Witnesses (Questions 123-154)

Chair: Thank you for attending this morning. Perhaps you would be kind enough to introduce yourselves briefly.

Dr Parker: I am Miles Parker. I am the Deputy Chief Scientific Adviser at the Department for Environment, Food and Rural Affairs.

Professor Collins: I am Professor Brian Collins. I am the Chief Scientific Adviser, Department for Transport.

Professor Slingo: I am Professor Julia Slingo. I am the Chief Scientist at the Met Office.

Q123 Chair: Our previous session with witnesses slightly overran because I think colleagues found some of the contradictions coming from them intriguing. You all three were at the heart of the matter. Who assumed leadership of this emergency and how did it evolve?

Professor Collins: My understanding is that the Prime Minister took the decision to call a meeting of SAGE and asked John Beddington, now Sir John Beddington, the Government Chief Scientific Adviser, to form up a SAGE group. I believe that was on the Friday. John sent a message to all the Chief Scientific Advisers and others whom he thought could contribute for names of people who could provide the expertise to form a SAGE meeting, and John chaired that first meeting on the following Wednesday. So it was the then Prime Minister's initiative. I should add, of course, that we were in purdah at the time when this incident occurred.

Q124 Chair: When the Cabinet Office was managing this, was there sufficient expertise there to deal with emergencies like this?

Professor Collins: You suggest that the Cabinet Office had been—

Chair: The Prime Minister himself.

Professor Collins: I see what you mean. I think that is exactly why he asked Sir John Beddington to create a special group around this particular topic because it was immediately seen that it was extremely complex. A large number of disciplines needed to interact with each other to understand the nature of the problem and what the possible solutions might be. That is why he went through John to get an external group of people together, as you have heard in the previous evidence.

Q125 Chair: Had the Government been ignoring warnings about the potential risk from volcanic eruptions?

Professor Slingo: I will go back to your first question because I think it is important that the Committee understands that, as soon as the volcano erupted, as the agency responsible for natural hazard emergencies and well used to dealing with them, we immediately alerted the Cabinet Office, the CAA and the Civil Contingencies Secretariat, and we had a member of staff in the Civil Contingencies Secretariat within an hour. So that had all happened as soon as the volcano erupted. We were well aware of it by Thursday and looking at the meteorological situation and so forth. I was called by Sir John on Saturday and spent Sunday with him in the Cabinet Office.

The processes around natural hazard emergencies and our role as operating and providing the London VAAC got into gear very, very early on.

Professor Collins: That was separate from forming up SAGE.

Professor Slingo: Yes, but a COBRA was called and the Civil Contingencies Secretariat went into full activity immediately with our engagement and providing advice right from the word go. We immediately set our teams in place and the operational process of the forecasting, what we were doing about monitoring, etcetera, etcetera, all went into full swing by the end of that week.

Q126 Chair: Previous witnesses have suggested that the radar evidence that you were relying on from Iceland was not up to scratch. When were you aware of that and when were Sir John and others notified of that?

Professor Slingo: In terms of the radar?

Chair: Yes.

Professor Slingo: We don't rely solely on any radar evidence.

Q127 Chair: No. I didn't say you relied solely on it. I asked when you were aware that the radar that you were partly relying on was inadequate.

Professor Slingo: We have always known that in terms of quantifying the source would always be challenging. I think we need to be clear that at the start of this emergency the guidance from ICAO, which goes to the VAACs, is for the VAACs to advise on the ash/no ash boundary. Our duty to the VAAC is to say, "Is there ash there?", not "How much ash is there?" Actually, we were the first VAAC, and indeed the first Met, to have to start producing forecasts about ash concentration as opposed to where ash is. So the issues around knowing the source term really came to the fore as soon as it became apparent that we would have to move from ash/no ash, which is quite constrained by the meteorology rather than the source term, to concentration, which is constrained both by the meteorology and what's coming out of the volcano.

Going back to your question about characterising the source, we were in very close contact with the Icelandic Met Office, who were working with the Icelandic Earth Science Department, who are very experienced in Iceland volcanoes. We were talking to BGS. We had aircraft reconnaissance of the plume. We had satellite information about the plume. To be fair, it's not what is coming out of the volcano at the volcano that matters for us. It is what was about tens of kilometres downstream where the big stuff had dropped out and you were left with a fairly stratified plume with the ash that would actually influence airspace. That was what we were looking at all the time. We were not relying that strongly on the radar to tell us about the source because it can't. It's not designed to give all the information required.

Q128 Chair: But it has been replaced?

Professor Slingo: There is a new one. There is an Italian one that we talked about, which is en route and will be in place, I believe, next week.

Q129 Chair: In your written submission you mention six-monthly contingency planning exercises. Was the Government really unprepared? There do not seem to be any contingency plans for this event.

Professor Slingo: Yes, we have these six-monthly planning tests and they are done using the current weather conditions so we go through the process. I think when we talk about being unprepared we have to understand that the meteorology that was prevailing at that particular time was almost the worst possible situation that you could get meteorologically. I remember thinking, when it first erupted and looking at the weather maps, we're in some trouble here because this is not going to change for several days and the flow is bringing the ash almost directly over the UK. It's very unusual. So the combination of the nature of the volcano and the meteorology put us in a place that, with the best will in the world, even through a lot of six-monthly testing with the real weather conditions at that time, and testing all our processes and all our modelling, to anticipate an event like that in advance is very, very tricky.

That being said, if we were just required to provide ash/no ash guidance, which is what the London VAAC was required to do, we did a fantastic job. Despite what other witnesses have said—I have the evidence and we showed it at the CAA conference—the comparison between the model's forecast of the extent of the ash cloud and what we observed very clearly from satellites and from other ground-based observations was incredibly accurate. So I think we were doing a really good job with what we were required to do at that time.

Q130 Gavin Barwell: I have three questions for you about the working of SAGE. First of all, in terms of transparency, neither the membership nor the minutes of the SAGE meetings have been published. Why is that?

Professor Collins: I discussed that with Sir John Beddington about two hours ago. He, of course, is reporting to you later. There isn't a secretariat in the context of the way this particular SAGE group was put together because of it being led from No. 10 at that particular point in history. So John is well aware that the record is not yet published. It is in preparation. I think you need to ask him whether there were factors that he felt were appropriate at the time that would have suggested it shouldn't be published.

Gavin Barwell: You didn't. We will do that.

Q131 Chair: Can you see any reason why it shouldn't have been in the public domain?

Professor Collins: I can see some sensitivities, yes, but I believe you should ask Sir John what they are.

Q132 Chair: I am asking you what your view is.

Professor Collins: I don't want to answer that question in a public domain.

Q133 Stephen Mosley: Did you have to sign non-disclosure agreements as part of your conditions?

Professor Collins: I am an adviser to Government so I don't have to sign a non-disclosure agreement.

Q134 Stephen Mosley: Did others?

Professor Collins: Yes.

Stephen Mosley: They did. Okay.

Q135 Gavin Barwell: My second question is about the timing of the SAGE meetings, so that the first meeting actually occurred on the day that UK airports re-opened.

Professor Collins: That was the Wednesday.

Q136 Gavin Barwell: 21 April?

Professor Slingo: Yes; that's right. The full SAGE met on Wednesday.

Q137 Gavin Barwell: There was a telephone conference the day before, I think?

Professor Collins: Yes, there was.

Q138 Gavin Barwell: The full meeting was the day they re-opened. Was there a reason that it took that time to get the SAGE meeting for the first time?

Professor Collins: You were involved before that.

Professor Slingo: As I said, I was involved with Sir John on the Sunday. We had discussions then, with myself and Sue Loughlin, whom you have just talked to, and we were asked to provide suitable names to represent the meteorology and the volcanology, particularly across academia and people who had not got vested interests. So by Monday I had provided Sir John with a list of names that I believed represented well the research aircraft community that you have heard from, from the academic community in terms of LIDAR technology, scattering processes, all that sort of atmospheric physics community and the meteorological weather conditions-type community. Sue Loughlin did the same on the volcanology. Those phone calls were then made on the Monday. There was a teleconference and that group met on Wednesday. It is hard to do it much faster than that.

Q139 Gavin Barwell: I will press a little bit on that. Obviously, the decisions that were being made in terms of shutting down UK airspace had a very significant impact on individual companies and on the UK economy as well. Is the time it took to identify those people perhaps an indication that this wasn't a risk that had been particularly anticipated? If you look at some of the other things that are on the Government's risk register, is there already drawn up a view that, "If this happens, these are the people we would get on to SAGE" and you would get a meeting quicker? Is that why it took a little time?

Professor Slingo: I think that's probably a fair comment, yes.

Q140 Gavin Barwell: My final question on SAGE is about the process for appointing people and whether you feel, with hindsight, that the right balance of expertise was on there from the start. I think we got the impression from our previous evidence session that, at least initially, there weren't necessarily people with engineering experience in terms of the operation of engines and what the tolerances might be.

Professor Collins: At the first meeting it is perfectly true to say, because those people were seriously busy dealing with their activity, and there aren't many of them, that at the first meeting they weren't present. Sir John and I had private meetings with the Chief Engineer of Rolls-Royce in the gap between the first meeting and the second meeting of SAGE. He was represented, as were the CAA engine experts, at the next meeting. So from that point on, as a result of identifying that that was a community we needed at that table, the answer is correct. Yes, we moved as quickly as we could.

Q141 Stephen Mosley: Having heard Professor Collins' earlier answer, my question is probably best off being pointed at Sir John Beddington when we talk to him. Can I just come back on something that we had in the first discussion? It was just the issue that Mr Stringer was raising about the difference between the model and the actual evidence, when you sent the aeroplane up there. We are told that you might have the answers as to the actual levels of ash that you discovered when you went up there. Could you just let us know? Did you find ash, what concentrations were they in and did they fit in with what the model was predicting?

Professor Slingo: When we moved on to having to talk about how much ash we believed was in the atmosphere, those measurements became crucial. From the point of view of was there ash/no ash, the reconnaissance flights in the early part of the emergency were finding ash where we expected it to be. As I have said, we then had to move to saying how much ash was up there. The other point about this particular event and the meteorology is that we had a high pressure system so the ash was layering. It was being stratified into layers with quite large amounts. So for us it was more about, "What's the peak concentration? What is the risk of exposure?". So we were required to talk about peak concentrations. So the red and black areas, which we have been hearing about, which were the 2x10-3, 2x10-4g/m3, those, not just from the aircraft but also from our ground-based instruments—this is LIDARs, aerosondes and so forth—all suggested that we were pretty accurate, within an order of magnitude, which, when you think about the range of values that you could get in a situation like that, showed we were pretty close on the peak concentrations.

That was a very important point for us because, even if we can't characterise the source, we can back-calibrate the source by the monitoring that we had in place over the UK, from aircraft and, indeed, from satellite observations. There are ways—it is quite scientifically challenging—that you can retrieve concentrations. We had scientists working on that throughout this episode.

I think a fair assessment is that, for the peak concentrations, we were within at most an order of magnitude and probably better than that. So the ash was there. It was at the levels pretty much that we were predicting it to be. That is a remarkable achievement considering that we had to move from saying "Is ash there?" to "How much?" within, literally, five days.

Professor Collins: Yes.

Professor Slingo: I can assure you my scientists were working long hours with no breaks for several weeks. It was a very challenging period for us.

Professor Collins: Could I just pick up on a question that Mr Stringer asked earlier about accuracy of measurement? The accuracy, as you have just heard, order of magnitude, that was about as best you could achieve.

Professor Slingo: Yes.

Professor Collins: The margin between where the safety limit was set and where we knew ash damage would occur in an engine, as described by the consortium of engine manufacturers, who, you have just heard, got together to decide what that number would be, left another factor of 100 between what they saw as damaging to the peak concentration that the measurement that the Met Office had said. So we combined all those uncertainties together in that process within about 10 days of the volcano going up, from a standing start. I don't know whether that actually answers the question you were asking, but I felt it was relevant to the uncertainty that maybe you were left with.

Q142 Graham Stringer: I will come to a question I've not yet asked. Is this work peer reviewed and publicly available, where you say that you are accurate within an order of magnitude?

Professor Slingo: Of course it's not peer reviewed yet, because this was new science. The papers are being reviewed now in the literature, so we have a series of papers that cover the observations, that cover the models, that actually even cover some of the sensitivity tests that we have been doing with the models to try and look at the range of uncertainties that might have arisen due to not knowing the particle size distribution accurately and not knowing the vertical structure of the source term.

In terms of observational evidence, we were putting that stuff out on our website at the time along with the five-day forecasts of the plume concentrations that we were asked to do by Government. So all that information is freely available. The observations were on the website. So those of a scientific bent could have looked at them and seen evidence of this layering that I've talked about and some of the evidence for the sorts of concentration values.

Professor Collins: There was also an event that was held jointly, which you have already heard about, sponsored by the CAA and SAGE, which was attended by a very wide audience. All of the science and all of the considerations that SAGE had been talking about was discussed on that day. The airlines were there in force at the most senior level.

Q143 Graham Stringer: When you are talking about being accurate within an order of magnitude, what are you talking about? Are you talking about getting the level at which the ash was accurate so that you knew precisely where the layering was or are you talking about concentration?

Professor Slingo: I am talking about peak concentrations.

Q144 Graham Stringer: But not, actually, the location of it in a vertical axis?

Professor Slingo: We can't be entirely accurate about the vertical location because of the way the model is constructed and the computational cost. We could put many more vertical layers in. But, again, you have to say to what degree can you evaluate that and is that useful information? Later on, and actually during the whole event, we were looking at between what flight levels the ash was situated. That's fairly important information. But to say exactly in the vertical where these layers were a day or two ahead is extremely difficult, but, even with that, we have good evidence that the model was doing a remarkably good job. These layers were descending slowly towards the surface, the old ash layers, and the model was capturing all those processes. The meteorology is a major driver.

There is a key point here as well. Our global weather forecasts are, arguably, the best in the world alongside the European Centre for Medium-Range Weather Forecasts in Reading. The meteorology that drives the dispersion of the ash was actually a really key factor in also getting the concentration and the structure of this major ash plume right. The weather forecasts at that time were extremely good so it is the combination of state-of-the-art atmospheric dispersion modelling with state of the art global weather forecasting which gave us quite a lot of confidence in what we were doing and what we were saying.

Q145 Graham Stringer: The Royal Aeronautical Society, the Airport Operators' Association, British Airways and Manchester Airport have all criticised your lack of responsiveness to their criticism that the inputs into the model were poor. How do you respond to that criticism?

Professor Slingo: We know that the uncertainty in the source term is an issue. We were looking at that and adjusting it on a six-hourly basis with the advice we were getting from the Icelandic Met Office, the Icelandic Earth Sciences Department, BGS—

Q146 Graham Stringer: I don't quite understand that. There was a limited amount of source information, wasn't there, from Iceland around when the volcano went off? How could you change that?

Professor Slingo: I think Sue Loughlin talked about the relationship between the height of the—there are various things. You can look at the height of the plume. You can also look at the lightning activity within the plume. We were also using that to give us some idea of the intensity of the volcano. We have satellite observations. We had information downstream, certainly coming into the UK, which would give us an idea of whether we had the mass amounts anything like right. As I said, we were in an order of magnitude on peak concentrations.

In terms of the changing nature of the source, the volcano was changing after the first eruption quite rapidly at times. We were re-doing our forecasts on a six-hourly basis and adjusting the source term as soon as we had any change in information about the activity. That, on occasion, meant that there were what appeared to be random changes in the forecast from one six hours to the next, but that's the nature of the beast you are dealing with. You can't forecast volcanic activity in the same way that you can forecast the weather.

Q147 Graham Stringer: I understand that. Maybe I am not making myself clear. The criticism was that the actual information from the source was poor quality going into the model.

Professor Slingo: Yes.

Q148 Graham Stringer: Those organisations, in all their submissions, are critical that you were unwilling to accept that the data input was itself inaccurate, not that the model didn't work.

Professor Slingo: I totally disagree. We have been very clear right from the word go that a major constraint on the accuracy of the ash concentration forecast has to be in the definition of the source term. We are all agreed. It's a major recommendation. At the Met Office we have done a major review of what happened during that emergency and one of our strongest recommendations is to get a better handle on not so much what's actually coming out of the volcano in the vicinity of the volcano but what exits finally in this contained plume that enters into the free atmosphere downstream of the volcano.

We have a couple of additional recommendations. One is that we need an aircraft that can really get into these plumes. With the CAA and DfT we are just completing the tendering process for fully instrumented aircraft, a civil contingency aircraft, that will be on 24-hour call, fully instrumented. It's a turbo prop. It's not a jet so it can fly where our BAe 146 could not fly safely. That will be ready early next year to go. So that will be invaluable in telling us to the north of Scotland what's coming our way because actually that is far more useful to us than knowing exactly what's coming out of the volcano at the volcano.

Then the other thing is that we have what we call "sondes" that can be launched from the surface or dropped from an aircraft which have a package of instruments on that look at aerosols. They look at particle sizes, composition, mass concentrations. At the time of this event we had three of those instruments available. They are research instruments. They were used, and that is part of the evidence that we had for knowing what the peak concentrations are. We now have 20. We can deploy those from the surface or we can drop them out of an aircraft through the plume. So, for me, we understand that that is a major constraint on the confidence of the ash concentration forecast and we are acting on it. So we've never denied that there was uncertainty there.

Q149 Chair: Dr Parker—I think this is more or less agreed—there are other areas where safety considerations are paramount where we expect the producer to collect data on behalf of Government. In this case, isn't there an argument for the airline industry collecting data on behalf of Government?

Dr Parker: If you are referring to the environmental issues—

Chair: Yes.

Dr Parker: No, they are not, really, because most of them are happening at ground level rather than at the upper layers.

Q150 Chair: So you see a difference between ground level activity and things in the air?

Dr Parker: Our concerns were entirely with what might have been deposited in water, in breathable air or on the ground.

Q151 Chair: I know that was your concern. On many of your ground-based activities you require industry to collect regular data and feed it into your models. Isn't there an argument that says the same should apply for the airline industry in terms of helping out on things like this?

Dr Parker: I find it difficult to see how they could. We were happy to get information from whatever source it was available, but in this case I am at a loss to know what it is they could contribute.

Q152 Chair: Did the BA test flights have a wider scientific value? Should we encourage them to do more of them?

Dr Parker: Again, I take your point but they didn't give us the sort of information which would have told us what the ground level conditions were going to be. So in that sense, no, they are not helpful.

Q153 Stephen Metcalfe: Very briefly, because I am aware of the time, firstly, do you think the current emergency is over, secondly, is it going to happen again, and, thirdly, are we better prepared and what have we learnt from the previous experience? That is for all three, really, I suppose.

Dr Parker: Okay. Very quickly from my end, in technical terms, it's only over when the Icelandic geologists tell us it's over. In terms of what was actually happening on the ground, we have had zero results in a long while. So we feel it's over in that sense.

Have we learnt a lot? Yes, a good deal, and it's been helpful in building up our knowledge of who are the right people to call on at the right time.

Are we better prepared? I think we had most of our preparations in place. We had a risk assessment based on an earlier volcanic explosion which related to the veterinary issues we might have faced. Our biggest difficulty at the time was finding somebody to analyse fluorine in grass samples. We managed that quite quickly. Yes, I think we learnt some useful lessons there.

Professor Collins: I think the answer for the particular volcano that erupted in April is yes because it isn't erupting now. Iceland is one of the densest parts of the planet with regard to where volcanoes exist. So will it happen again? Certainly. When? I haven't a clue, but it absolutely certainly will happen again.

Are we better prepared? My observation is that we were pretty well prepared in a lot of disjointed areas. What this episode showed us how to do, and quickly, was to bring those disjointed areas together in a very constructive and collaborative way to deliver as quickly as possible a solution that got us out of a situation that could have been unsafe and we didn't know, so we erred on the side of safety, to a situation that we now know to be safe, but we still need to do a lot more work.

Are we better prepared? Absolutely, because we now have that community working together and it is still continuing to work, as Julia has just said, on a number of the critical aspects were there to be another volcano in the near future.

Given the resource constraints, we, I think, have to look to the market, going back to the Chairman's question just now. We do have to look to the market just a wee bit more than perhaps we have done in the past to help us with the experience of what actually happens when aircraft fly through airspace which has got stuff in it, whether it is volcanic ash, ice or anything else. We need to get the science of observation in airspace better coupled to the experience of aviators who fly through it. That is a piece of work that, maybe, we haven't done as much of yet as we should do. In the current economic climate, if you say to anybody "Add to your cost base", that's not going to go down well, but, nevertheless, we ought to be addressing it.

Professor Slingo: Yes, the current emergency is over, but I think it would be wrong for us to take our foot off the pedal in terms of the research, the development of the forecasting capability, the monitoring systems, because, for sure, this was a wake-up call of how bad it could be. Next time, of course, the meteorology may be a lot more friendly. We may not be hit with such a difficult situation. There is no doubt, certainly within the Met Office, that we are pushing ahead with improving the forecasting process and particularly recognising the need to actually say something about concentrations now, which is going to be very demanding for us.

Q154 Chair: All of those three answers have financial implications—

Professor Slingo: Yes.

Chair: —yet we still owe money to NERC?

Professor Collins: We do because the NERC aircraft existed which, of course, had it not existed we would have been in much more difficult straits. It is worth considering that the fact that we put 30 years' worth of investment into atmospheric science, into meteorology, into modelling, into volcanology through our science base, gave us the ability to react very quickly. I agree we have a financial short-term issue to resolve but actually the fundamentals of continuing to invest in making sure we are not vulnerable in the future are probably more substantial and maybe slightly trickier. That's the current ICAO road map for what is happening. We are, from an aviation point of view, still working extensively and collaboratively on an international front to ensure that not just our airspace but European airspace, with respect to Iceland, is much better understood in these circumstances.

Chair: Thank you very much for your time.

previous page contents

House of Commons home page Parliament home page House of Lords home page search page enquiries index

© Parliamentary copyright 2011
Prepared 2 March 2011