Saturday, April 28, 2012


date: Wed May 5 13:49:25 2004
from: Phil Jones <>
subject: Re: Paper on ERA-40/CRU comparisons

Got most pressing things cleared so here are a few comments on the paper. With a few
changes I'm happy for this to go as an ECMWF report, but I'd really like to see this
a paper. More important as I've taken on the convening lead-authors job for the Atmos.
Obs. chapter in the upcoming IPCC report. I'm the CLA with Kevin Trenberth and we'd both
like to refer to this work.
I realise you want to stay onside with Eugenia, but you did refer to her reply and I
the comments in Nature are totally in order. There are problems comparing with max/min
obs. temps and with the 00, 06, 12, 18 data from any reanalysis. I'm still hopeful of
the max and min temp datasets for another paper - in addition to the one you've almost
I did go to Ming's talk at the EGU, but he confirmed the opinion I got from someone
he isn't that careful. He didn't check his ppt slides and he couldn't show his analysis
as they wouldn't project as the system didn't have the software he thought would be there
I also can't imagine that Eugenia has had hundreds of positive comments and didn't mention
the famous scientist ! I think her method would get the same result anywhere in the world
it is just a result of the analysis and is clearly evident in many of the figures we'll be
in the report and paper.
Anyway, enough of that and back to the paper.
I really enjoyed reading it and it is very clear and easy to follow.
1. Add climatological to the branches of research in the first para.
2. in the para on 2 on K+C it isn't just over land, but the global series.
3. Same para, changed non-elevated to non-mountaineous or some other better phrase.
4. NCEP/NCAR did incorporate surface pressure obs.
5. not just agricultural land-use but all land-use changes. Also these changes might
differences of either sign.
6. On p4, beginning of section 3 emphasise anomalies, by mentioning absolute values as
well. Say that we didn't use these as such comparisons are likely just to be a result of
differences in elevation fields between what you use and the stations. We've been
normals fields over the Alps between 3 different datasets and most of the differences come
from different elevational fields the various groups have used when interpolating data.
7. The Fig 1 and 2 differences are apparent up to the early 1980s (just in the NH) and
clearly in the SH.
8. I will send you the Turner et al ref details. Sent an email to John.
9. On Fig 5 on p7 I'd say something more about the seasonal cycle nature of the plots
and that NCEP/NCAR is more marked.
10. On p7 mention that CRU is working to correct those where CRU is clearly in error. With
the HC we're working on HadCRUT3 and correcting all these and revising normals is part
of that work, scheduled for summer/early autumn.
11. With Table 4 emphasise that many of the differences are in high northern lats and all
in winter, which suggest that problems with snow and especially sea-ice fields are likely
12. Your trend selection of only 48 missing months is very stringent. Just add the fact
is very stringent.
13. Small para on p9 should refer back to Fig 3.
14. Can you speculate on a reason for the change in character of the increment (near
of p11).
15. Bottom of p11. The issues with Greenland could be due to our assumption of specific
lapse rates from coastal stations for estimation over interior parts of Greenland might be
fault. I would look to include some of the 10years worth of AWS data from the ice core
sites if we ever do that work again.
16. The first para of Section 5 could do with a better intro to say why the section is
Also presumably volcanoes are not in the model.

As I said earlier I'd be happy to come down in June or July if you want to discuss the
paper from the report some more. I've too much on in May to contemplate this.
Here this week and next till Weds if you want to call.
At 08:07 26/04/2004 +0100, you wrote:

You might look out for Ming Cai in Nice. See below. I've let him know I will not be
there, but did not know you would be. I'll forward you Eugenia's initial response also.
Best regards
Dear Adrian,
Thanks for sending the manuscript to us. Since I will be in EGS meeting next week,
Eugenia and I would not be able to get together to discuss your paper till my return
from the trip.
Meantime, I assume that you may be also attending the EGS meeting at NICE. If so,
we could have a lunch or a brief discuss during the break. I will present a paper
co-authored with Eugenia at 9:00AM on Thursday (April 29) morning in Session CL11
(Lecture Room Euterpe). The title is "Can reanalysis have anthropogenic climate trends
without model forcing?" I think your work strengthens our arguments.
I look forward to meeting with you and discussing with you on implication of your
work on our Nature paper and on the work I am presenting at the EGS meeting.
Ming Cai
by "Cai, M; Kalnay, E"
has been scheduled for an oral presentation in Session CL11,
Lecture Room Euterpe on Thursday, 29 April 2004, 9:00.
f028 wrote:

I've downloaded a copy, but am in Nice at the EGU for the rest of this
week. Back in at UEA on May 4.
A paper in either J. Climate or JGR (Atmospheres) would be good.
I'll give this some thought when I get some time. JGR would be
cheaper for colour. Also Climate Dynamics is reasonbaly cheap for colour.

===== Original Message From =====
Phil and ECMWF colleagues
Attached is a reasonably polished version of a paper comparing CRU,
ECMWF and NCEP analyses of surface air temperature. Many of you have
seen a much earlier version. It's in a format that we can put out
quickly as an ECMWF project report, after which I think it's worth
turning it into a Journal article, which will entail at least dropping a
lot of colour from the plots, and probably a few of the time series.
I'd appreciate your comments on the paper as it stands for an ERA-40
report, and any suggestions as to what might be cut (or added) to make a
paper for ? Journal of Climate. I've tried to address comments
received from Phil on an early draft. One specific question for Phil: Do
you have the full author list for the Turner et al. paper? I'll send a
copy to Eugenia, as I would not want to put this on the web without
giving her a chance to respond to the remarks about her letter to Nature
with Cai.
Are you all happy with the author list? I hope this is not too much of a
surprise for Sami and Nils. I think Sami deserves to be there for
writing the OI T2m analysis in the first place and for his observational
database work for ERA-40, and Nils deserves to be there for getting the
AMIP-style simulation done, which I think adds quite a bit to the paper.
Best regards
Adrian Simmons
Head of Data Division
European Centre for Medium-Range Weather Forecasts
Shinfield Park, Reading, RG2 9AX, UK
Phone: +44 118 949 9700
Fax: +44 118 986 9450

Adrian Simmons
Head of Data Division
European Centre for Medium-Range Weather Forecasts
Shinfield Park, Reading, RG2 9AX, UK
Phone: +44 118 949 9700
Fax: +44 118 986 9450

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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