date: Wed Jul 6 08:57:41 2005 from: Phil Jones subject: Fwd: Misc to: n.nicholls@bom.gov.au Neville, Here's an email from John, with the trend from his latest version in. Also has trends for RATPAC and HadAT2. If you can stress in your talks that it is more likely the sondes are wrong - at least as a group. Some may be OK individually. The tropical ones are the key, but it is these that least is know about except for a few regions. The sondes clearly show too much cooling in the stratosphere (when compared to MSU4), and I reckon this must also affect their upper troposphere trends as well. So, John may be putting too much faith in them wrt agreement with UAH. Happy for you to use the figure, if you don't pass on to anyone else. Watch out for Science though and the Mears/Wentz paper if it ever comes out. Also, do point out that looking at surface trends from 1998 isn't very clever. Cheers Phil Date: Tue, 05 Jul 2005 07:59:51 -0500 From: John Christy User-Agent: Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 X-Accept-Language: en-us, en To: Phil Jones Subject: Misc X-NSSTC-MailScanner: Found to be clean X-NSSTC-MailScanner-SpamCheck: not spam (whitelisted), SpamAssassin (score=-5.8, required 5, BAYES_01 -5.40, RCVD_IN_ORBS 0.11, SIGNATURE_LONG_SPARSE -0.49, USER_AGENT_MOZILLA_UA 0.00) X-MailScanner-From: john.christy@nsstc.uah.edu X-Spam-Score: 0.0 X-Spam-Level: / X-Spam-Flag: NO Hi Phil: I've been getting round-about versions of rumors concerning our newly adjusted version 5.2 LT dataset. I believe I had indicated earlier to you that the correction was within our published margin of error. In any case here are the numbers that describe various aspects of v5.2 1979-2004 Global Trend +0.115 UAH, +0.125 RATPAC and +0.137 HadAT (note, when subsampled for the same latitudes in which sonde observations are available, UAH and HadAT are almost exactly the same.) Update of site by site comparison of UAH LT 5.2 and SH radiosondes from Christy and Norris 2004: All 87 SH stations, no adjustments Raobs + 0.028 UAH +0.040 74 best sites with adjustments Raobs +0.030 UAH +0.054 These SH changes from the original publication were very minor because most stations were outside the tropics where the diurnal error had essentially no impact. A paper by Sherwood claims that Day minus Night is a legitimate way to go about looking at sonde problems. The real problem though is that Day minus Night is only an indicator of a sonde change, it does not determine the change itself. Most notorious is the Philipps Mark III to Vaisala RS-80 where the night warmed by about 0.3 C and the day by a little bit less, which means the Day minus Night reveals a negative shift when in fact both ob times have a significant positive shift (these sondes form a signifciant part of the LKS dataset). Similar results occur for US VIZ mini-art 2 to Micro-art software in 1990. I have many other sone comparisons, and all are more consistent with the UAH trends more than RSS and certainly VG. Indeed, I was curious to see that your name was on VG's latest paper. I wish I had time to fill you in on why the addition of the non-linear terms is a red herring (both UAH and RSS have performed the calculations with and without the non-linear terms with no impact on the trends) and why the latitudinal difference for calculating the coefficients leads one astray. I'm a little nervous now that you may have a "dog in this fight" as we say in Alabama while writing up the IPCC. I expect my sonde comparisons to be included in the IPCC and I will have further results demonstrating the problems with the Day minus Night technique within a few months. I've lots to do now. Thanks for listening. John C. -- ************************************************************ John R. Christy Director, Earth System Science Center voice: 256-961-7763 Professor, Atmospheric Science fax: 256-961-7751 Alabama State Climatologist University of Alabama in Huntsville [1]http://www.nsstc.uah.edu/atmos/christy.html Mail: ESSC-Cramer Hall/University of Alabama in Huntsville, Huntsville AL 35899 Express: Cramer Hall/ESSC, 320 Sparkman Dr., Huntsville AL 35805 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 ----------------------------------------------------------------------------