cc: t.osborn@uea date: Mon, 19 Apr 1999 15:34:23 +0100 from: Keith Briffa subject: Re: Science commentary to: "Raymond S. Bradley" Ray thanks again for taking the trouble to look through this . We are expecting a revised version from Science and as soon as it arrives we will consider all the points and try to incorporate ammendments to satisfy everyone I hope. How about forwarding the last Mann message to me so I can reply directly?! Best wishes Keith At 09:49 AM 4/19/99 -0400, you wrote: >I've just ploughed through the mountain of email regarding your Science >"perspectives" article. For what it is worth (probably not much) I will >add my comments on this (amazingly) controversial commentary. In the >context of what you were asked to do by Science, I don't find the overall >perspective too problematical. Clearly, it is YOUR perspective and you are >entitled to express it if so invited. However, there are a few topics that >might be worth revising. >1. You could point out that the SH data we use contributes to explaining >the variance of NH temperature, or leave out the sentence on p. 2, para 2: >"Four of the records..." >2. You should mention that some reconstructions undertake verification (ie >Mann et al 98, 99, & [crudely] Bradley & Jones...not sure about the >others...) & point out how important that is... >3. As you point out the limitations of long-term tree ring data (ie >replication, standardization etc) it would be appropriate to say to what >extent these issues are a problem or not, in Mann et al 99 vis a vis other >efforts. >4. Mike's point re the baseline for comparing records is right. You should >align them on the basis of the calibration periods, more or less... >5. You should expand on the caption to say which are "NH" annual/seasonal/ >extra-tropical etc... >6. Mike's point that the late Holocene decline should be visible in your >2ka reconstruction makes no sense to me. I think it is quite likely that >the penultimate millennium showed a warming trend. Nevertheless, I wonder >if comparing this series with the others is worth it, given the limited >data set it represents, lack of verification, & other limitations you >elaborate on earlier.... > >Ray > > > >Raymond S. Bradley >Professor and Head of Department >Department of Geosciences >University of Massachusetts >Amherst, MA 01003-5820 >Tel: 413-545-2120 >Fax: 413-545-1200 >Climate System Research Center: 413-545-0659 >Climate System Research Center Web Site: > > -- Dr. Keith Briffa, Climatic Research Unit, University of East Anglia, Norwich, NR4 7TJ, United Kingdom Phone: +44-1603-592090 Fax: +44-1603-507784