date: Tue, 19 May 2009 12:20:51 +0100
from: C G Kilsby <REDACTED
subject: RE: URGENT advice needed on Weather Generator
to: "'Phil Jones'" <REDACTED
>, "'Humphrey, Kathryn (ACC)'" <REDACTED
>, "'Jenkins, Geoff'" <REDACTED
>, "'Roger Street'" <REDACTED
I'm away 25-28 too.
From: Phil Jones [REDACTEDREDACTED
Sent: 19 May 2009 12:13
To: Humphrey, Kathryn (ACC); C G Kilsby; Jenkins, Geoff; Roger Street
Subject: RE: URGENT advice needed on Weather Generator
I'd be happy to do this. I'm away next week May 25-28.
At 11:13 19/05/2009, Humphrey, Kathryn (ACC) wrote:
Thanks Phil, Chris and Geoff- I am whacking all of this into a document to take through
with Robin later.
I know this is extremely frustrating for you and completely understand where you are
This is a political reaction, not one based on any scientific analysis of the weather
generator. We did the peer review to take care of that. I can't overstate the HUGE
amount of political interest in the project as a message that the Government can give on
climate change to help them tell their story. They want the story to be a very strong
one and don't want to be made to look foolish. Therefore, every time they hear about
any criticisms from anyone, they jump.
I'll let you know how I get on in dealing with this today. It might be helpful if you
come in, Chris and Phil, and speak direct to Robin as well at some point soon. Would
you be happy to do this?
From: Phil Jones [ REDACTEDREDACTED
Sent: 19 May 2009 10:40
To: Humphrey, Kathryn (ACC); Chris Kilsby; Jenkins, Geoff; Roger Street
Subject: Re: URGENT advice needed on Weather Generator
What would be a good start to the first question would be to switch it around to who
doesn't need the WG! As I've said on numerous occasions, if the WG isn't there,
all the people that need it will go off and do their own thing. This will mean that
individual sectors and single studies will do a whole range of different things.
This will make uncertainties even larger!
The UKCIP helpdesk will get the continual question - how do I get daily output?REDACTED
As for those that need it. The EA will need it, they have a scoping study which
will show them how to use it. Similarly UKWIR have a scoping study doing much the same
thing. I'm involved in the latter, which is being led by Atkins. There are a number of
EPSRC projects that need it. What all these projects need are daily time series data
for input into time series models (agricultural crop models, building design, river
modelling and water resources, and there are likely many more).REDACTED
Anyone who wants to look at sequences of temperature and precipitation in the future
will need it. Many users are expecting it!
WRT point 2, I'd have thought it was fully integrated into the reports. It is in the
and probably mentioned in the Science report.
WRT point 3, if the WG was at 25km scale, users would try and scale it down to 5km
and you'd be back to users doing a whole range of different things. There is a section
the WG Report (5.2) on the scale issue.
We can't do the WG at the 25km scale, as this is the RCM grid! The observed data are
available at the 5km OS grid or at station (point) scales. They are not available at
the 25km RCM
rotated pole scale. No observed data are available on this scale/resolution. Many users
find it difficult to cope with the rotated RCM grid, and will say why can't the output
the OS grid.
Just seen Geoff's reply - totally agree, the scale issue is a red herring. What
There is an issue of user knowledge. The size of the WG output files means that
will need to know what they are doing when they get their output. Those working for the
EA, UKWIR and within the above projects will. It is likely that Joe Public and media
Have any of these 'sensible scientific experts' have read the WG Report or read the
Document? We have been through the international peer review like the rest of the
We had a lot less to respond to than the science report. Why don't we (Chris, Geoff,
get a chance to talk to these 'sensible scientific experts'! Are we not deemed
'scientific', or 'expert' enough? I know you're only the messenger, Kathryn!
It seems to me that your Director, and DG etc have no idea what users want or how
UKCP09 will be used.
PS Colin will have some results comparing UKCP09 for two sites (Ringway and LHR)
later this morning. These compare 2050s medium UKCP09 output (produced via the
interface) with a different RCM simulation produced by MOHC (with extra heat input
into major UK cities) from the SCORCHIO project. Colin will also redo the 10 key sites
by the end of the week. Everything so far, looks exactly as expected. Output
comes back in about 15 minutes now.
At 09:43 19/05/2009, Humphrey, Kathryn (ACC) wrote:
Could you please send me some comments urgently on the issues below. I have a meeting
with Hilary Benn this afternoon and this is likely to come up (at 4.30). As you know we
have already given him some advice on the weather generator but perhaps I need to give
them more on the validity tests etc as well. I think the problem here is that the
people in these meetings (my Director-General, Director and so forth) don't have the
technical background to be able to head off these criticisms at the time. The advice I
put up previously was to keep the WG in with the launch package.
Anyway as a start if you can give me responses to the three points below that would be
From: Mortimer, Robin (CALR)
Sent: 18 May 2009 20:00
To: Humphrey, Kathryn (ACC)
Cc: Unwin, Peter (NEG); Watson, Robert (SEG); Capstick, Jonathan (ACC); Maresh, Jennifer
(ACC); Lewis, Rupert (ACC); Cahill, Teige (ACC); Hurst, Martin (WaFERR); Hawley, Clare
(ACC); Packer, Kathryn (ACC)
Subject: advice needed on Weather Generator
Bob Watson, Peter Unwin and I spoke to Jackie McGlade this evening, along with Bob
Mitchell and James from Met Office.
After some initial misunderstanding about the nature of the criticisms Jackie McGlade
has been making about UKCP09, she clarified that she is very supportive of the approach
being taken to downscaling to 25km grid square level; and indeed would be willing to
champion this being adopted more widely across Europe. This is good news. We all
agreed (and Bob outlined the conclusions of the peer review panel on this point) that
there was of course a cascade of confidence as we move down from continental to 25km
scale, but, so long as the uncertainties were clearly presented, this was robust.
The remainder of the conversation focussed on the Weather Generator. JM raised two
issues on this (a) that the level of "statistical noise" involved in moving down from
25km to 5km scale meant that the results became so uncertain to the virtually worthless
and (b) the very fact that so many sensible scientific experts shared this opinion
risked discrediting the rest of the UKCP09 package - essentially everything was getting
`tainted' by the WG. She argued we should drop it. In response BM set out the
justification for the WG using the usual arguments.
As you know Ministers have also raised questions about this so we will need to go back
to them with some further advice, starting with a heads up at the meeting with SofS
Please could you provide some further advice on three questions - a quick initial view
by tomorrow afternoon insofar as this is possible would be v helpful: