From	Keith Briffa	Date	Thu Oct 19 17:55:41 2000
To	Tim Osborn
Subject	Re: JGR paper
I am just having to go so I will think about the "should we?" . The answer to the "can we?" is yes. I have spoken to the person organising the editorial review and she has promised me she will get it to us in the next week or so. If we can get it back immediattely she says we can make the December issue. Therefore it is possible to do the edits if it means very little change to the text. I have also confirmed that we will pay 1500 dollars for the colour and they say they are working on these now. I really want to get this into the 2000 so I can include it in the RAE. Ed is here now and has some great looking extended PDSI reconstructions (1000 years) for the western US. I am suspicious as to whether the negative trend in Mike's Hockey stick prior to the 20th century is not at least partly the result of a trend in the long high elevation western US trees he uses . Malcolm sent me some figures for the HIHOL meeting and in this work he cuts off the juvenile growth sections of the long tree data but does no detrending on the remainder. This might leave a linear age trend in these data. I remember that Mike in his long reconstruction , stated that the pc representing the western US stuff was essential for getting a verifiable result. Interesting , but only a diversion. We can discuss the JGR and other stuff in Avignon. Hope your weekend was a god one. I tend to agree a bout the NAO meeting- you could use the money (and perhaps time) to better effect. At 04:24 PM 10/19/00 +0100, you wrote: Keith, have you had to produce the camera-ready copy for the age-banded JGR paper yet? If not, then is it possible to make some minor changes to it? For the comparison with the Mann et al. reconstruction, I had previously just taken their land&marine full northern hemisphere mean annual temperature time series and re-calibrated it against the instrumental land north of 20N Apr-Sep mean temperature time series. Well, I have not taken the Mann et al. spatial temperature field reconstructions, and computed a land north of 20N area mean. I still have to re-calibrate it against the instrumental series because it is an annual rather than Apr-Sep mean. After doing all this, you'll be pleased to know that the final figure is only slightly different (the Mann et al. curve is very slightly more of an outlier during the 1500-1700 period, and is cooler and closer to observations post-1950, but not much different elsewhere). What does change, however, are the correlations. The correlations with instrumental data are slightly worse (from 0.76 to 0.73, and from 0.92 to 0.89 decadal), but I'm not sure that we show these anyway. But the cross-correlations between the Mann et al. and the other reconstructions (which we do show) are all stronger than previously - which now seems a little unfair on them. Cross-correlations between unfiltered series: Mann versus: Jones, Briffa (ABD), Briffa (Torn+Tai+Yam) before: 0.47, 0.36, 0.33 now: 0.50, 0.37, 0.34 Cross-correlations between 50-yr smoothed series: Mann versus: Jones, Briffa (ABD), Briffa (T+T+Y), Overpeck, Crowley before: 0.78, 0.43, 0.50, 0.86, 0.76 now: 0.81, 0.51, 0.55, 0.86, 0.78 I don't have a copy of the paper in front of me, but the 'before' values should match those in one of the tables. Some of the 50-yr smoothed new values are noticeably stronger. Can we make these changes still, or is it too late? And do you think we should? Cheers Tim