cc: Keith Briffa <k.briffa@uea.ac.uk>, Eystein Jansen <eystein.jansen@geo.uib.no>, trond.dokken@bjerknes.uib.no
date: Thu, 6 Jan 2005 09:23:42 -0700
from: Jonathan Overpeck <jto@u.arizona.edu>
subject: Re: Fwd: Re: [Wg1-ar4-ch06] IPCC last 2000 years data
to: hegerl@duke.edu

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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

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