cc: Tim Osborn , Malcolm Hughes , Keith Briffa , Kevin Trenberth , Caspar Ammann , rbradley@geo.umass.edu, tcrowley@duke.edu, jto@u.arizona.edu, Scott Rutherford , Tom Wigley , p.jones@uea.ac.uk date: Tue, 14 Oct 2003 10:09:04 -0400 from: Michael Oppenheimer subject: Re: draft to: "Michael E. Mann" Michael: I'm fine with the last paragraph. However, the section on latitude dependence of tree-growth data remains obscure. In particular, the sentence "In such cases, relatively recent (i.e. post 1950) data are not used in calibrating temperature reconstructions" leaves the impression that data is rejected because it doesn't fit expectation. For the uninitiated, you need a few words on why this procedure is acceptable, like perhaps "because confounding influences obscure the response to temperature" or whatever. Michael Michael "Michael E. Mann" wrote: Thanks Tim and Malcolm, The latest round of suggestions were extremely helpful. I've accepted them w/ a few minor tweaks (attached). We're at 765 words--I think AGU will let us get away w/ that... So, comments from others? Thanks, mike At 02:11 PM 10/14/2003 +0100, Tim Osborn wrote: SO3 argue that borehole data provide a conflicting view of past temperature histories. To the contrary, the borehole estimates for recent centuries shown in M03 may be consistent with other estimates, provided consideration is given to statistical uncertainties, spatial sampling and possible influences on the ground surface [e.g., snow cover changes--Beltrami and Kellman, 2003]. It is not meaningful to compare the late 20th century with a much longer period 1000 years ago [Bradley et al., 2003], especially given the acknowledged limitations [Pollack et al., 1998] of borehole data. ______________________________________________________________ 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 [1]http://www.evsc.virginia.edu/faculty/people/mann.shtml Attachment Converted: "c:\eudora\attach\omichael8.vcf"