Wednesday, April 25, 2012


cc: "'Humphrey, Kathryn \(CEOSA\)'" <kathryn.humphreyatXYZxyzRA.GSI.GOV.UK>
date: Thu Jul 10 09:18:02 2008
from: Phil Jones <>
subject: Re: UKCIP Comments on Annex 4
to: "Roger Street" <>, "'C G Kilsby'" <>, "'Jenkins, Geoff'" <>

Timely comments. I'm working on revising Ch 5 and also Annex 4. I'll send these
off to Chris tomorrow, as I'm away next week.
It would be very useful to get Ch 5 and Annex 4 read through again when we
have revised the text. Suggest this isn't all of the SG plus others, but a smaller
select group - mainly those that provided the majority of comments on the WG parts.
At 07:55 10/07/2008, Roger Street wrote:

I understand that it is now past the identified deadline; however I offer the following
comments in the interest of improving the presentation of Annex 4

Annex 4
As per comments on the overall report, when referring to the weather generator within
UKCIP08, it should be identified as the UKCIP08 weather generator and not just the WG.

Page 1, lines 4-5 Support the effort to provide a purpose for this annex. Suggest that
these statements should begin with what is the purpose of the annex, not by pointing the
reader to another section of the report. It would also help to describe the intent of
the annex from a readers perspective.

Page 2, line 7-8 Suggest simply explaining what is meant by the variance and skewness of
daily rainfall amounts and the lag-1 autocorrelation.

Page 2, line 9-10 It is not clear which estimation uses the daily gridded precipitation
dataset and for what purpose.

Page 2, line 16-17 The network of 115 stations across the UK covers which period in

Page 3, line 12-13 Suggest explaining why half month values were used in this case.

Page 3, line 18-19 Somewhat confusing as it was noted on page 2, lines 16-17 that
gridded data similar to precipitation are not yet available and here it says that all
the IVRs are either available on the 5kmX5km grid or have been interpolated to this

Page 3, line 23 Unable to find figure A3

Page 3, line 34-33 What are the implications of this assumption in terms of the results

Page 4, line 4-5 Suggest a little more information is needed about the limited
capability of the WG to reproduce extremes. This will be key and a major shortcoming
from the perspective of users.

Page 4, lines 10-13 Suggest that some rationale as to why these factors were chosen
could be helpful.

Page 5, lines 4-21 Suggest that there is a need to rethink the means (and validity) of
presentation of these equations. A little more explanation (such as what is each
equation showing) may be quite helpful

Page 5, lines 27-30 Suggest The hourly component of the UKCIP08 weather generator is
based on the hourly timescale. For the future weather generator simulations, it is
assumed that none of these relationships will change, principally because. It is not
apparent as to why little confidence in the RCM a GCM simulations at timescales less
than daily leads to the assumption in lines 28. Suggest some clarification.

Page 5, line 34 Not clear what is done for rainfall.

Page 6, line 25 It is not clear as to the type of application for which the UKCIP08
weather generator is being used. Is this an impacts, vulnerability or adaptation

Page 6, line 31 Believe that this is the first time that the initial seed is mentioned.
Suggest that some further explanation is needed

Page 6, line 34 Suggest impacts assessment rather than impact sector.

Page 7, lines 20-22 Suggest that like raised in the comment for page 4, lines 4-5, some
further detail related to the limited performance for events such as heatwaves is
required. This will also need to be covered from a use perspective within the UKCIP08
user guidance, but the rationale and nature of the limitation need to be spelled out in
the projections report (chapter 5 or annex 4).

Hope that these comments and suggestions can be used to improve the annex.


Technical Director
Dyson Perrings Building
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+44 (0)186 528 5713

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Prof. Phil Jones
Climatic Research Unit Telephone +44 (0) 1603 592090
School of Environmental Sciences Fax +44 (0) 1603 507784
University of East Anglia
Norwich Email

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