cc: myles , francis , Tim Barnett , Reiner Schnur , Phil Jones , Tom Crowley , Nathan Gillett , David Karoly , Jesse Kenyon , "Petty,Rick", christopher.d.miller@noaa.gov, "Pennell, William T" , klaus.hasselmann@dkrz.de, Gabi Hegerl , simon.tett@metoffice.com, td@gfdl.gov, Doug Nychka , Ben Santer , Karl Taylor , "Stott, Peter" date: Mon Jul 5 14:02:27 2004 from: Phil Jones subject: IDAG and Boreholes to: hegerl@duke.edu Gabi and Francis, On the boreholes, it is important to add these two references in on p7 by rewording the sentence beginning 'Recently, Mann et al (2003) ..' . Maybe Tom can do this. My problem is that I'm still trying to settle into our new house. I will be away some mornings this week and am trying to catch up with a lot of other emails that have come. Today is my first day in for about 2 weeks Also you've only sent a pdf version of the submitted paper, and I can't alter that. In the following section on paleo forcing and modelling studies, I would suggest that Tom replaces LIA references with dates. As for the specific comments on p 24-25 remove the second one which is repetitive. As for the first maybe remove 'controversy' and rephrase the sentence to be a little less definitive. One final thing, on p6 add in a reference ... (see reviews by Jones et al., 2001 and Jones and Mann, 2004). Jones, P.D. and Mann, M.E., 2004: Climate over past millennia. Reviews of Geophysics, 42, doi:10.1029/2003RG000143. I will be around if you can send me a revised draft in a few days and I can check what you've done. On some of the other issues, I like Fig 6. It is better than the scaling factors for lay readers. The oceans bit requires a bit of rework to add in some new references. Both reviewers want additional references in many places - it would seem another page or two. This will be good training for you Gabi with IPCC coming along ! I would hope that if we do this correctly and respond to each point adequately then the reviewers (neither of whom seem to want to go through it again) will not get the paper again and Dave Randall can do his editing job. Cheers Phil Dear Colleagues, Attached are two papers, recently published in the Journal of Geophysical Research - Atmospheres, to which I call your attention: Pollack, H.N. and Smerdon, J.E., Borehole climate reconstructions: Spatial structure and hemispheric averages, J. Geophys. Res. 109, D11106, doi:10.1029/2003JD004163, 2004 Rutherford, S. and Mann, M.E., Correction to "Optimal surface temperature reconstructions using terrestrial borehole data", J. Geophys. Res. 109, D11107,doi:10.1029/2003JD004290, 2004 The first paper presents a detailed study of the aggregation of individual borehole reconstructions to form a hemispheric average; the investigation also demonstrates that when the borehole reconstructions are properly aggregated, they display significant spatial correlation with the surface air temperature (SAT) at sub-hemispheric spatial scales. In this paper we also identify an error in the paper "Optimal surface temperature reconstructions using terrestrial borehole data" by Mann et al. [JGR 108(D7),4203, doi:10.1029/2002JD002532], and discuss the ramifications. Rutherford and Mann acknowledge the error in the second paper attached. I call these papers to your attention to help quell the propagation of the identified error, and to reiterate that in terms of an average northern hemisphere history over the past five centuries, the borehole reconstructions yield a warming of the ground surface of about 1K, half of which occurred in the 20th century. Cheers, Henry ___ ___ Henry N. Pollack [ \ / ] Professor of Geophysics | \/ | Department of Geological Sciences |MICHIGAN| University of Michigan [___]\/[___] Ann Arbor, Michigan 48109-1063, U.S.A. Phone: 734-763-0084 FAX: 734-763-4690 e-mail: hpollack@umich.edu URL: [1]http://www.geo.lsa.umich.edu/~hpollack URL: www-personal.umich.edu/~hpollack/book.html Prof. Phil Jones Climatic Research Unit Telephone +44 (0) 1603 592090 School of Environmental Sciences Fax +44 (0) 1603 507784 University of East Anglia Norwich Email p.jones@uea.ac.uk NR4 7TJ UK ----------------------------------------------------------------------------