cc: Ben Santer , Tom Wigley , Karl Taylor , Thomas R Karl , John Lanzante , Carl Mears , "David C. Bader" , "'Francis W. Zwiers'" , Frank Wentz , Leopold Haimberger , Melissa Free , "Michael C. MacCracken" , Phil Jones , Steve Sherwood , Steve Klein , 'Susan Solomon' , Tim Osborn , Gavin Schmidt , "Hack, James J." date: Thu, 10 Jan 2008 14:43:30 +0000 from: Peter Thorne subject: Dian, something like this? to: Dian Seidel All, as it happens I am preparing a figure precisely as Dian suggested. This has only been possible due to substantial efforts by Leo in particular, but all the other dataset providers also. I wanted to give a feel for where we are at although I want to tidy this substantially if we were to use it. To do this I've taken every single scrap of info I have in my possession that has a status of at least submitted to a journal. I have considered the common period of 1979-2004. So, assuming you are all sitting comfortably: Grey shading is a little cheat from Santer et al using a trusty ruler. See Figure 3.B in this paper, take the absolute range of model scaling factors at each of the heights on the y-axis and apply this scaling to HadCRUT3 tropical mean trend denoted by the star at the surface. So, if we assume HadCRUT3 is correct then we are aiming for the grey shading or not depending upon one's pre-conceived notion as to whether the models are correct. Red is HadAT2 dataset. black dashed is the raw data used in Titchner et al. submitted (all tropical stations with a 81-2000 climatology) Black whiskers are median, inter-quartile range and max / min from Titchner et al. submission. We know, from complex error-world assessments, that the median under-cooks the required adjustment here and that the truth may conceivably lie (well) outside the upper limit. Bright green is RATPAC Then, and the averaging and trend calculation has been done by Leo here and not me so any final version I'd want to get the raw gridded data and do it exactly the same way. But for the raw raobs data that Leo provided as a sanity check it seems to make a miniscule (<0.05K/decade even at height) difference: Lime green: RICH (RAOBCORE 1.4 breaks, neighbour based adjustment estimates) Solid purple: RAOBCORE 1.2 Dotted purple: RAOBCORE 1.3 Dashed purple: RAOBCORE 1.4 I am also in possession of Steve's submitted IUK dataset and will be adding this trend line shortly. I'll be adding a legend in the large white space bottom left. My take home is that all datasets are heading the right way and that this reduces the probability of a discrepancy. Compare this with Santer et al. Figure 3.B. I'll be using this in an internal report anyway but am quite happy for it to be used in this context too if that is the general feeling. Or for Leo's to be used. Whatever people prefer. Peter -- Peter Thorne Climate Research Scientist Met Office Hadley Centre, FitzRoy Road, Exeter, EX1 3PB tel. +44 1392 886552 fax +44 1392 885681 www.metoffice.gov.uk/hadobs Attachment Converted: "c:\eudora\attach\trend_profiles_dogs_dinner.png"