date: Mon Oct 5 13:16:07 2009 from: Phil Jones subject: Re: help please to: Tom Wigley Tom, I don't think AR4 (Ch 3) went into the TLT/surface amplification issue. You can get the pdf of the chapter from here [1]http://ipcc-wg1.ucar.edu/wg1/wg1-report.html . This amplification issue is only addressed in some recent papers - mainly Ben's. The timescale argument is quite convincing. It is a pity that there is only Pinatubo that you can test it on. El Chichon ought to work but it is confused by ENSO. Does the amplification work well for the 1997/98 El Nino? Did you pick up that Thompson et al paper due out in J. Climate soon? Factoring out ENSO and volcanoes might help in isolating this. [2]http://www.atmos.colostate.edu/faculty/thompson.php where there is a link to the paper and also the data [3]http://www.atmos.colostate.edu/~davet/ThompsonWallaceJonesKennedy/ It seems as though you can get all the extraction parts. No need for the dynamic bit. Anyway my thought is as Pinatubo gives the amplification then ENSO ought to as well. A thought might be to take Dave Thompson's ENSO and volcanic subtraction series, then scale them by thermodynamic theory value then subtract these from RSS and UAH. Small issue of base periods to sort out and assume there is no lag. Need to do this with NCDC surface as well - have to use Dave T's numbers here. This can't do the 20N-20S - just the globe. It would of course, at this and any other time, be very nice to show that UAH is wrong. A couple of minor things in the paper - the amplification should work for a cooling as well - not just warming trends? In Fig 5 in your legend LOUAH should be UAHLO. This is in Fig 4 as well. By the way - meant to add this to the earlier email. NCDC ERSST3 side does talk about missing data, so any of this would mean the (NH+SH)/2 won't equal the global average that NCDC calculate. I recall you asking about GISS. One thing I have learned about GISS is that they have a cut off date of the 8th of each month. After this date nothing is changed for the previous month and nothing earlier either. This means they never incorporate any back data and they don't get the second tranche of CLIMAT data which comes about the 16th of the following month. Countries like Paraguay and Bolivia mostly come in this way, plus some in Africa. I'll see Tom Peterson later in the week. I'll ask him about their cut offs. I think they don't change a month later. This won't lose you much data though. It was Tom who told me about the data they can't use. Cheers Phil At 05:25 04/10/2009, Tom Wigley wrote: Hi Phil, I'm writing a report for EPRI where I have to discuss the instrumental temperature record. What they are particularly concerned with is/are the criticisms that have been leveled at the surface record, especially differences from MSU data. I think CCSP 1.1 does a good job on this -- not sure about AR4 (which I need to re-check). But things have changed since CCSP 1.1 and AR4, and I think I can make a better case against UAH than either of these reports. Could you please look at the attached and give me your opinion and comments (tracked if that makes it easier)? In my view, the evidence that the UAH data are flawed is overwhelming -- but I want to make the case in a logical and balanced way. Have I succeeded? The audience level for this is IPCC report level, perhaps a bit lower. So I need to be relatively simple, but authoritative. The MSU issue also comes up later in my report where I discuss the IJOC Santer et al. paper -- which is only mentioned briefly in the attached extract. One thing I thought I might add is more about the other two surface data sets. A key point may be that 1998 is not the warmest year in the GISS record -- do you trust GISS? I've not looked at NOAA. Perhaps this still has 1998 as warmest? Thanks for your help. By the way, this report was due to EPRI last week. I'm hoping to get it to them by Friday (9 Oct.) Best wishes, Tom 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 ----------------------------------------------------------------------------