Examination of Witnesses (Questions 123-154)
Chair: Thank you for attending
this morning. Perhaps you would be kind enough to introduce yourselves
Dr Parker: I am
Miles Parker. I am the Deputy Chief Scientific Adviser at the
Department for Environment, Food and Rural Affairs.
I am Professor Brian Collins. I am the Chief Scientific Adviser,
Department for Transport.
I am Professor Julia Slingo. I am the Chief Scientist at the Met
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?
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?
You suggest that the Cabinet Office had been
Chair: The Prime Minister
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
Q125 Chair: Had
the Government been ignoring warnings about the potential risk
from volcanic eruptions?
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.
That was separate from forming up SAGE.
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?
In terms of the radar?
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.
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?
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.
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
saidI have the evidence and we showed it at the CAA conferencethe
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?
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?
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.
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
I am an adviser to Government so I don't have to sign a non-disclosure
Q134 Stephen Mosley:
Stephen Mosley: They did.
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
That was the Wednesday.
Q136 Gavin Barwell:
Yes; that's right. The full SAGE met on Wednesday.
Q137 Gavin Barwell:
There was a telephone conference the day before, I think?
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?
You were involved before that.
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?
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.
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?
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 instrumentsthis is LIDARs, aerosondes
and so forthall 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 waysit
is quite scientifically challengingthat you can retrieve
concentrations. We had scientists working on that throughout
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.
I can assure you my scientists were working long hours with no
breaks for several weeks. It was a very challenging period for
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.
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
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?
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
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
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?
I am talking about peak concentrations.
Q144 Graham Stringer:
But not, actually, the location of it in a vertical axis?
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
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?
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?
I think Sue Loughlin talked about the relationship between the
height of thethere 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
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.
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.
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
ParkerI think this is more or less agreedthere 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
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
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.
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
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
Chair: yet we still
owe money to NERC?
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.