cc: Keith Briffa , Eystein Jansen , trond.dokken@bjerknes.uib.no date: Thu, 6 Jan 2005 09:23:42 -0700 from: Jonathan Overpeck subject: Re: Fwd: Re: [Wg1-ar4-ch06] IPCC last 2000 years data to: hegerl@duke.edu Hi Gabi - Keith has the green light to be comprehensive and thus supportive of your chapter in the way you describe. I've seen some of it, and it's going to be good I think. Stay tuned, best, Peck >Hi again, we have a figure with forcing and simulations >for last 1-2 millenia drafted by Pascale, but there is not a lot of >forcing discussion in the chapter for the last millenium apart from a >timeseries in pascales figure. Mostly, we are drawing on >you guys. Our section on the last millenium simulations not very detailed, >focusing more on the big picture (20th century sticks out) than the >individual episodes (like medieval warm period/maunder minimum). >I think this was what we approximately decided how to slice it >but its been a while.... > >Gabi > >On Wed, 5 Jan 2005, Keith Briffa wrote: > >> Hi Peck (et al) >> I am considering comments (including David's) re last 2000 years - some are >> valid = some are not . Will try to chop out bits but we need this >> consensus re the forcing and responses bit - I am for keeping the forcings >> in as much as they relate to the specific model runs done - and results for >> last 1000 years as I suspect that they will not be covered in the same way >> elsewhere . David makes couple good points - but extent to which forcings >> different (or implementation) perhaps need addressing here. The basic >> agreement I mean is that the recent warming is generally unprecedented in >> these simulations. >> It will take time and input from the tropical ice core /coral people to do >> the regional stuff well . I think the glaciological stuff is a real problem >> - other than just showing recent glacial states (also covered elsewhere) - >> of course difficult to interpret any past records without modelling >> responses (as in borehole data), but this requires considerable space . My >> executive decision would be to ask Olga to try to write a couple of >> papragraphs on limits of interpretation for inferring precisely timed >> global temperature changes? What do others think? I only heaved Olga's >> stuff in at last moment rather than not include it - but of course it needs >> considerable shortening. The discussion of tree-ring stuff is problematic >> because it requires papers to be published eg direct criticism of Esper et >> al. We surely do not want to waste space HERE going into this esoteric >> topic? All points on seasonality , I agree with , but the explicit stuff >> on M+M re hockey stick - where is this? ie the bit about normalisation base >> affecting redness in reconstructions - sounds nonsense to me ? >> >> I have to consider the comments in detail but am happy for hard direction >> re space and focus. If concensus is no forcings and model results here fine >> with me - Peck and Eystein to rule >> Keith >> >> >> > >-------------------------------------------------------------------- >Gabriele Hegerl >Dept. of Earth and Ocean Sciences, Nicholas School of the Environment >Duke University, Durham NC 27708 >phone 919-684-6167, fax 919-684-5833 >email: hegerl@duke.edu http://www.eos.duke.edu/Faculty/hegerl.html >--------------------------------------------------------------------- -- Jonathan T. Overpeck Director, Institute for the Study of Planet Earth Professor, Department of Geosciences Professor, Department of Atmospheric Sciences Mail and Fedex Address: Institute for the Study of Planet Earth 715 N. Park Ave. 2nd Floor University of Arizona Tucson, AZ 85721 direct tel: +1 520 622-9065 fax: +1 520 792-8795 http://www.geo.arizona.edu/ http://www.ispe.arizona.edu/