cc: "'David R. Easterling'" date: Thu Apr 21 08:33:47 2005 from: Phil Jones subject: Re: Chapter 3.4.1 to: Kevin Trenberth , David Parker , Brian Soden Kevin, A very slightly revised 3.4.1 attached. It reads well and the CCSP-based figures are fine. Not keen on their use of running means, but the message is clear. Agree on deleting the highlighted bits of text. Added in the word radiances a few times, wrt raw MSU data. Cheers Phil At 17:13 18/04/2005, Kevin Trenberth wrote: Hi Phil and David, and Brian I believe you three are probably closest to the satellite temperature record issue and so I am sending this to you. I have thoroughly gone over all the comments we received and I have prepared a revised 3.4.1 which is attached. This is the cleaned up version. The actual version has tracking turned on but the changes are so extensive that they are very hard to follow. As you know, I have read the entire CCSP report and commented extensively on it. I know Phil was on the review team and David was there as a lead author. However David and Phil may not be as familiar with the whole report. Obviously this remains a controversial topic. Many of the comments we received were diametrically opposed to one another. The rhetoric was disappointing (especially from Peter Thorne). In fact Peter's comments are mostly not useful and reveal very strong biases against Fu and reanalyses. Previously, you'll recall that David provided most of the text and I edited it and updated it with the Fu material in a somewhat ad hoc fashion that got almost everyone mad. Probably a good thing to do in retrospect, as this next version will look so much better. Note that I have done nothing with the appendices at this point, so that needs to be addressed. I have taken out all the tables?? You will see even in the current text that I have 2 sections I would like to delete. While individual comparisons of radiosonde station data with collocated satellite data (Christy and Norris, 2004) suggest that the median trends of radiosonde temperatures in the troposphere are generally very close to UAH trends and a little less than RSS trends, trends at individual radiosonde sites vary and root mean square differences of UAH satellite data with radiosondes are substantial (Hurrell et al., 2000). Moreover, as noted in 3.4.1.1, comparisons with radiosonde data are compromised by the multiple problems with the latter, and there are diurnal cycle influences on them over land. In the stratosphere, radiosonde trends are more negative than both MSU retrievals, especially RSS. [DELETE THIS?] The problem here is the rhetoric of Christy et al. In his contribution Christy justifies the UAH record by saying that "median trends agree with those of sondes". But he actually sent to us his Fig. 2 showing the lack of agreement in general. It is only the median that agrees, the agreement with sondes individually is not good and this is just for trends. [Hence the median depends on the selection of stations]. It is even worse if rms differences are examined (as in Hurrell et al 2000). The only reason to include this is to rebut Christy's claim. For most other readers it has no business being there. Your suggestions appreciated. Maybe this should go in the appendix? You will see that I have stolen 2 figures from the CCSP report. I made up the 3rd figure from data provided from the CCSP report plus extra material (only the global is in the current draft). It would also be nice to include a spatial map of trends at the surface and for the troposphere (T2 corrected as from Fu) but no such figure exists anywhere, yet. We can get trends from RSS and UAH for T2. It would be good to have access to the originals so we can modify them and clean up the terminology. {On that score, I don't think the CCSP terminology is tenable given the new retrievals of Fu et al (2005) and ours, using T2, T3, and T4 is much easier). At present the CCSP report is not very useful to us. Some figures are useful. It may become so, but I actually have my doubts, given the vested interests of the authors. I am tempted to send this to Tom Karl in his role as editor of our chapter, and of course he is head of the CCSP effort, but I would NOT want him to use it for CCSP (except that it might highlight the differences in assessments). What do you think? Via Tom we might get better access to the figures and updates? Also I'l l cc David Easterling. This would be the main basis for FOD. Ideally also it is desirable to get the figures updated thru 2004, but can we? Please read this version and let me know what you think? (Please be kind, I have put in a LOT of work on this) Best regards Kevin -- **************** Kevin E. Trenberth e-mail: [1]trenbert@ucar.edu Climate Analysis Section, NCAR [2]www.cgd.ucar.edu/cas/ P. O. Box 3000, (303) 497 1318 Boulder, CO 80307 (303) 497 1333 (fax) Street address: 1850 Table Mesa Drive, Boulder, CO 80303 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 ----------------------------------------------------------------------------