Wednesday, November 30, 2011


cc: Chris Folland <>
date: Fri Oct 15 11:04:40 2004
from: Phil Jones <>
subject: Re: IPCC Chapter3
to: "Thorne, Peter" <>, "Parker, David (Met Office)" <>

I've just sent an email to David about this. Maybe if I send you the email that Kevin
send to Per Kallberg at ECMWF, you'll see what should be in the box on Reanalyses
and their use as climate records.
Getting all these bits of text pieced together will be a challenge and it is likely we
not get it right at the first draft. There are 3 other meetings to either completely
rewrite or
more hopefully fine tune the zeroth order draft.
Hi Per
The section you were asked to help on is an appendix Box: maybe half or up to 1 printed
page of text in IPCC format or order 1 page single spaced 12 point font on A4 plus small
figure. The appendix is about techniques, measurement systems etc. This box should be
about reanalyses and and the challenges of creating a homogeneous and continuous climate
record. Recall this is for IPCC with a focus on long-term change. So my thoughts on this
would be to summarize quickly the observing system and how it changes over time, and its
quality. The bias corrections for satellites should be dealt with and how well you think
it turned out. We might be able to add a small figure (like the one of all the satellites
as fn of time?). The bottom line should be a clear assessment of what the reanalyses can
be used for (variability?) and what they can not (trends, decadal?).
This is an opportunity to both highlight the reanalyses with a realistic assessment of them
for many people, and also advocate for the next steps. This is in contrast to the request
I earlier sent to Adrian which was really to exploit the reanalyses to the extent possible
and say something about the climate record itself. I'll follow up on that separately.
At 10:41 15/10/2004, Thorne, Peter wrote:

David (cc Chris, Phil),
I still think this is fundamentally a wrong headed decision. We are not
just talking about MSU here, but general principles of trying to create
CDRs from raw data that has been maintained with operational rather than
climate monitoring principles at the heart of it. This applies to
satellites as equally as to radiosondes. In fact in satellites it is
easier to understand as there are less d.o.f. in the choices of raw data
and yet we still get a huge range of results. I maintain that having a
box for the raobs but not for satellites brings an Animal Farm mentality
to the report: "All UA obs are equal, but some are more equal than
others" could be a very obvious (and dangerous) take home, unless I am
alone in being as suspect of satellites as raobs, which I hope I'm not.
I argue we take one of the following options:
1. fold the raobs box into the reanalysis one
2. set up a separate box for satellite obs
3. expand the remit on my box to UA climate and not limit ourselves
solely to raobs there which I'd be happy to do. That would require a bit
more space, but not a huge amount.
On Fri, 2004-10-15 at 10:22, Parker, David (Met Office) wrote:
> Kevin
> Thanks.
> Maybe the Reanalysis box should be entitled "Changes in Satellite and
> other Observing Systems and their impacts of reanalyses" to make it
> clearer.
> Jim Renwick has responded with an invite to Chris Folland. Our email
> addresses have changed from to and the
> change could, conceivably, have caused a problem.
> Regards
> David
> On Thu, 2004-10-14 at 17:56, Kevin Trenberth wrote:
> > Hi David
> > I am thinking that the box on "Changes in observing system impacts on
> > reanalyses" will deal with inhomogeneities in satellite data and other
> > data, and so I am less inclined to focus on this issue just for the
> > MSU. Anyway that was the thinking. We can see how it works out.
> >
> > I will follow up with Jim: I have to say I have not heard from him since
> > Trieste, so I have been assuming he has been doing as we requested. But
> > maybe not.
> >
> > Dian Siedel was replaced in both places by Melissa Free. That should be
> > on the revised annotated outline and on the updated list of CAs.
> > Melissa is at the same organization.
> > Kevin
> >
> > Parker, David (Met Office) wrote:
> >
> > >Kevin
> > >
> > >We have just had an internal meeting on our contributions to IPCC and
> > >the following were noted:
> > >
> > >The outline chapter has a box on adjustments to homogenize radiosondes,
> > >allocated to Peter Thorne. He comments that there should be one also on
> > >adjustments to homogenize satellite retrievals...otherwise we give the
> > >impression that while radiosondes have problems, satellite data are
> > >perfect! Could we ask Carl Mears to write a box?
> > >
> > >
> > >Some invitations from LAs have not yet been received, e.g. Chris Folland
> > >hasn't had one from Jim Renwick on atmospheric circulation.
> > >
> > >Have we found a replacement for Dian Seidel on (radiosonde
> > >humidity)?
> > >
> > >Thanks for your efforts!
> > >
> > >David
> > >
> > >
> > >
> > >
> > >
Peter Thorne Climate Research Scientist
Hadley Centre for climate prediction and research
Met Office, FitzRoy Road, Exeter, EX1 3PB
Tel:+44 1392 886552 Fax:+44 1392 885681 [1]

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

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