cc: "'Humphrey, Kathryn \(CEOSA\)'" 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'" Roger, 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. Cheers Phil 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 time? 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 grid. 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 (sensitivity)? 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 assessment? 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. Roger Technical Director UKCIP-OUCE Dyson Perrings Building South Parks Road +44 (0)186 528 5713 UKCIP's website has been relaunched, with improved navigation and a host of new features. [1]www.ukcip.org.uk 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 p.jones@uea.ac.uk NR4 7TJ UK ----------------------------------------------------------------------------