date: Thu Nov 5 08:31:28 2009 from: Phil Jones subject: Re: Clarification on data availability to: phil@greenbridge.com Phil, I wouldn't believe this some person - the one you linked to. Of course I don't agree with this assertion. I doubt that Pat Michaels has read through the papers I sent you details of yesterday - the one on the CRU Temperature web page and the one I attached. The dataset isn't changing that much. We recently added revisions to many stations in the Alpine area as a result of an EU project. In the last couple of years we've also added revised data for Canada, Australia and NZ. We've yet to write these up, but I can tell you the net effect if essentially zero change to trends over the time periods that the IPCC report used. There are differences but they are well within the error estimates of individual years that Brohan et al (2006) produced. There is a paper coming out soon in JGR which shows excellent agreement with the latest set of Reanalyses performed in Europe. This should prove to people that the record is reliable. It is an extension of this paper attached. In the attached NCEP and ERA are incorrect before the late-1970s because of the problems discussed in the paper - mainly the lack of satellite estimates before this time. It would take a few months to get back to what we had in the mid-1980s. As I said yesterday the effort would be a waste of resources. Cheers Phil At 02:27 05/11/2009, you wrote: Phil--thanks for the prompt reply. If I understand you correctly, you remove data series because of things such as urbanization effects that affect the station errors, or the stations moving? I suppose this means the data set is always changing because of these issues? When you say you could reassemble it quite easily, how long would it take? To which state would you reassemble it if it is always changing? Some [1]people are saying that this means there are no "reliable records of global surface temperature" because of this. Do you agree? Many thanks Phil Phil Jones wrote: Phil, Yes - we could reassemble it quite easily. We have all the adjustment factors. We also have the lists of the few stations totally removed (~150). We could get these back from GHCN. These were removed because of urbanization effects and multiple jumps/moves. We're not keen on doing any of this as we know it is a complete waste of time. To know why read this paper. Brohan, P., Kennedy, J., Harris, I., Tett, S.F.B. and Jones, P.D., 2006: Uncertainty estimates in regional and global observed temperature changes: a new dataset from 1850. J. Geophys. Res. 111, D12106, doi:10.1029/2005JD006548. You can get this from here - [2]http://www.cru.uea.ac.uk/cru/data/temperature/ This links to the pre-publication version. Look in this paper about homogeneity adjustments - and see that they have hardly any effect. See also the attached - Figure 6. Apart from the stations that we deleted (which we can get back) we haven't deleted anything. We never had the original records to destroy anyway - the relevant Met Services have these! I know the web says other things - but hardly anybody has ever bothered to check with me or look over our web site. A lot of people read what they want to read..... Cheers Phil At 16:11 04/11/2009, you wrote: Hi Phil, Can you kindly clarify this statement regarding data availability from CRU's [3]website : "We, therefore, do not hold the original raw data but only the value-added (i.e.quality controlled and homogenized) data.". Does this mean that to if CRU wanted to recreate the value added data you would have to reassemble the original data? There is information on the web, such as [4]this, that the data has been "destroyed." Is this true? Thank you Phil -- Phil Green Greenbridge Management Inc. 905-271-6262 land/cell [5]http://www.greenbridge.com [6]phil@greenbridge.com 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 [7]p.jones@uea.ac.uk NR4 7TJ UK ---------------------------------------------------------------------------- -- Phil Green Greenbridge Management Inc. 905-271-6262 land/cell [8]http://www.greenbridge.com [9]phil@greenbridge.com 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 ----------------------------------------------------------------------------