From	Michael E. Mann	Date	Mon, 06 Jan 2003 09:13:24 -0500
To	Tim Osborn, Scott Rutherford
CC	Keith Briffa, Phil Jones, ray bradley, Malcolm K. Hughes, Michael E. Mann
Subject	Re: RegEM manuscript
Thanks very much Tim, Your comments are extremely helpful. I'm open to eliminating the comparison w/ Esper et al --but lets see if there is a consensus of the group as to what to do here. We're anxiously awaiting comments from the others... thanks again, mike p.s. Scott can be reached at either U.Va or U.RI email equally well (I believe the former is forwarded to the latter).. At 12:16 PM 1/6/2003 +0000, Tim Osborn wrote: Dear Scott and Mike, Over the Christmas break I (finally!) had time to read the RegEM manuscript in detail. Phil had already read and annotated a copy - so I've added my annotations to that and will mail it to you today. Mike asked for comments to go to Scott, so please tell me which address I should use (Rhode Island or Virginia?). I spoke to Keith and he has partly read it too, and will provide separate comments soon. Overall, I think the paper is a very nice piece of work and I'm pleased to be involved with it. The results regarding robustness with respect to proxy data, method, region and season are definitely good to publish. Among the many comments annotated on the manuscript, a few are repeated here so that all authors may respond if they wish: (1) Given the overwhelming number of values in the Tables, I suggest halving them by dropping all the CE values (keeping just RE values). As the paper points out, getting the verification period mean right is rewarded by RE but not by CE. Since we are interested in changes in the mean, I don't think that's a problem. CE is fine in addition, but dropping it would provide benefits of reducing manuscript size - and especially the size of the tables. (2) The "mixed-hybrid" approach sounds dubious to me - more justification/explanation of why it is needed (and hence why it captures more variance than the simpler splitting into high- and low-frequency components method). (3) It is not clear to me that the paragraph and figure on the comparison with Esper et al. are either correct or necessary. They also are problematic because it would appear that we (Briffa & Osborn) were contradicting our earlier paper when in fact we aren't. The paper is already long and to remove these parts would therefore be helpful anyway. The comparison with Esper et al. is important - but much better dealt with in a separate paper where it could be developed in more detail and with more room to explain the approach and its implications. (4) I still hope to write up some more detailed comparisons of the reconstructions using just the MXD data but different methods and will let Mike/Scott know my plans on this soon. Happy new year to you all. Tim Dr Timothy J Osborn | phone: +44 1603 592089 Senior Research Associate | fax: +44 1603 507784 Climatic Research Unit | e-mail: t.osborn@uea.ac.uk School of Environmental Sciences | web-site: University of East Anglia __________| [1]http://www.cru.uea.ac.uk/~timo/ Norwich NR4 7TJ | sunclock: UK | [2]http://www.cru.uea.ac.uk/~timo/sunclock.htm _______________________________________________________________________ Professor Michael E. Mann Department of Environmental Sciences, Clark Hall University of Virginia Charlottesville, VA 22903 _______________________________________________________________________ e-mail: mann@virginia.edu Phone: (434) 924-7770 FAX: (434) 982-2137 [3]http://www.evsc.virginia.edu/faculty/people/mann.shtml References 1. http://www.cru.uea.ac.uk/~timo/ 2. http://www.cru.uea.ac.uk/~timo/sunclock.htm 3. http://www.evsc.virginia.edu/faculty/people/mann.shtml