cc: "Martin Juckes" <M.N.Juckes@rl.ac.uk>, <hegerl@duke.edu>, "Keith Briffa" <k.briffa@uea.ac.uk>, <t.osborn@uea.ac.uk>
date: Fri, 25 Feb 2005 14:53:45 -0000
from: "Myles Allen" <m.allen1@physics.ox.ac.uk>
subject: Millennial temperatures
to: "Eduardo Zorita" <Eduardo.Zorita@gkss.de>, "Jan Esper" <esper@wsl.ch>, "Anders Moberg" <anders@misu.su.se>

Dear Eduardo, Jan and Anders,

I have been asked (on rather short notice) to put together a team of
international experts to perform an inter-comparison and evaluation of
reconstructions of temperatures over the past millennium on behalf of
the Dutch government.  Essentially, they have allocated 80keuro to this
task and are soliciting bids -- my understanding, reading between the
lines of the e-mails from the project manager, is that we may be the
only bidders, but if there are rival bids and if you happen to be
putting together another one, then please accept my apologies, and rest
assured I won't take offence if you simply ask me to go away.

The resources offered are not large, and they would like deliverables on
a six-month timescale, so we clearly can't break a lot of new ground
with this. What I thought would be useful would be to put together a
common piece software in an accessible language like IDL or Matlab to
take a common set of input proxy series and reproduce reconstructions
using several different algorithms. I'm sure we won't be able to do this
for all the algorithms out there, but if we can do this even for just a
couple, then we can put down a framework for other authors to make their
own input to. This way we can document exactly whether reconstructions
differ because of inputs, processing philosophy, or simply tunable
parameters. 

Gabriele Hegerl and I did something like this (with Nathan Gillett)
pulling together different detection and attribution results in the
build-up to the IPCC TAR, and although it sounds rather mundane, it was
actually incredibly valuable for the TAR because it meant the chapter
authors understood the origins of the differences between the studies'
results in a nice, impersonal environment. We would aim to make this
code publicly available to accompany a review paper at the conclusion of
the project. A nice extension would be to apply the various algorithms
to some pseudo-proxy data from models, but this would depend on us not
tripping over other pieces of research currently under way.

My colleague Martin Juckes (at the Rutherford Appleton Laboratory) is
pulling together the current version of our outline bid, which currently
involves myself, Gabriele Hegerl (with whom I have been working on
another regression based reconstruction with Tom Crowley), Keith Briffa
and Tim Osborn (who have also been looking into regression-based
approaches).

Would you be prepared to participate in this exercise, specifically with
Jan and Anders contributing the details of their respective
reconstruction algorithms and Eduardo advising on the details of the MBH
algorithm?  At present we were envisaging salary support for Martin and
Gabi, and travel support possibly supplemented with a small consultancy
fee if regulations allow for everyone else. At the very least, this
should fund us all getting together for a practical workshop sorting out
the code -- I'm sure we can choose somewhere nice for the purpose!

Looking forward to hearing from you (please copy Martin in on any
response) and congratulations to Anders on the impact of your paper:
well deserved.

Yours sincerely,

Myles Allen

Climate Dynamics Group
Atmospheric, Oceanic and Planetary Physics
Department of Physics, University of Oxford
Tel: 44-1865-272085/925
Fax: 44-1865-272923
E-mail: myles.allen@physics.oxford.ac.uk

