date: Wed, 19 Nov 2008 08:11:37 +0000 from: Rob Wilson subject: Re: a request to: Keith Briffa , Tom Melvin Hi Keith and Tom, first, please note that I am based at St. Andrews now - so e-mail and address (in signature) are different. Thanks for considering me as a "fair" referee. I am also busy putting together a proposal with Neil Loader for Dec 1st so I am aware how tense the next few weeks could be. What you propose is indeed relevant, especially w.r.t. the MXD data and the regional 'divergence' noted in your 2002 paper. I would be happy to be a referee, but I think it only fair if I make some brief critical comments at this early stage w.r.t. your project: 1. The 400 chronology database you plan to work with is somewhat outdated and many of the chronologies do not go into the 1990s. I think this could be a potential problem and any reviewer might be quite sceptical to see yet more money put into a data-set which has been processed multiple times. Importantly, with greatest warming being in the last decade or so, a crucial test for any divergence related project would be to assess whether the chronologies can model that recent warming. This will likely not be possible with the current data set. It may be crucial to add in to your proposal an update section as well. I understand that it is not possible to update all 400 sites, but from the current data that are available, it is possible to identify those sites with the strongest climate signal. Surely the project could be greatly strengthened if some of these keys sites could be updated to present. There is certainly much more data out there than the original 400 sites and you may need to consider expanding your analysis beyond the original data-set. 2. I think it should be made clear that divergence is not noted everywhere and some areas appear to be worse than others. E.g. Alaska and the NW Territories appear to be a particular hot spot. However, in the Millennium project we have not noted any calibration issues in the recent period. There are also a whole ream of potential factors that could lead to a divergence phenomenon. Yes, your wording is carefully worded (e.g. "overcoming at least part of the apparent divergence "), but I think you must consider all possible factors in your analysis. We certainly should be careful in taking the instrumental data as bible truth in some locations. There is also my Tmax hypothesis (which I know you do not agree with) which has now been tested in both the Pyrenees and N. Yukon and appears to hold in those regions where there is a significant difference in turned between Tmin and Tmax (something that I have been meaning to test in a more global way). 3. You need to carefully rationalise why you need 30 months for such a project. Even if you processed one RW and one MXD chronology per day, there would be a lot of time left over and I am sure the chronologies can be processed much quicker than that. I hope these comments are of some use regards Rob Keith Briffa wrote: Dear Rob Please see attached letter Keith -- Professor Keith Briffa, Climatic Research Unit University of East Anglia Norwich, NR4 7TJ, U.K. Phone: +44-1603-593909 Fax: +44-1603-507784 [1]http://www.cru.uea.ac.uk/cru/people/briffa/ -- ----------------------------------------------------------------------- Dr. Rob Wilson Lecturer in Physical Geography School of Geography & Geosciences University of St Andrews St Andrews. FIFE KY16 9AL Scotland. U.K. Tel: +44 01334 463914 Fax: +44 01334 463949 [2]http://www.st-andrews.ac.uk/gg/people/wilson/ ".....I have wondered about trees. They are sensitive to light, to moisture, to wind, to pressure. Sensitivity implies sensation. Might a man feel into the soul of a tree for these sensations? If a tree were capable of awareness, this faculty might prove useful. " "The Miracle Workers" by Jack Vance -----------------------------------------------------------------------