I’m up to 38 emails back and forth with Science now in trying to get data. A little more drifted in April, about which I’ll report on in a couple of posts. My most recent progress report was here
One of the questions pertained to a discrepancy between the correlation between gridcell temperatures and foxtail chronologies reported by Osborn and Briffa and the actual correlation. Osborn supplied the information that they used – they used data only going back to 1888, while the HadCRU2 gridcell goes back to 1870 and there was a significant difference between the correlations when 1870 was used instead of 1888. Since there appeared to be an ad hoc use of data, I requested an explanation of the discrepancy and corresponding information for other gridcells as follows:
6. I acknowledge receipt of a temperature data set from 1888-1990. The HadCRU2 data set contains temperature data for the gridcell 37.5N, 117.5W commencing in 1870. However, the gridcell information provided by Osborn commenced only in 1888 and the differences are material to the final result (0.045 versus 0.18 reported). What is the reason for commencing this comparison in 1888 rather than the available 1870? Why is there no notice of this in the SI? Since there is a material difference in this example, could you please provide the gridcell temperature sets in a comparable format for the other 13 Osborn and Briffa series.
Osborn and Briffa sent an explanation to Science, which was forwarded to me, together with the corresponding information. The explanation shed some interesting light on CRU temperature data, which many readers of this blog are interested in. (As you all know, CRU’s station data is confidential.)
Unfortunately, Science advised me that the Osborn and Briffa explanation was itself confidential and not for public posting without permission of Osborn and Briffa, which to date has not been forthcoming. Osborn and Briffa are both at CRU in England and intersted readers may wish to contact them personally for a confidential explanation.