date: Thu May 20 13:56:35 2004
from: Phil Jones <p.jones@uea.ac.uk>
subject: Re: [Fwd: Re: Paper on ERA-40/NCEP/CRU comparisons]
to: Adrian Simmons <Adrian.Simmons@ecmwf.int>

    Adrian,
        Methinks they try to defend their paper too much ! The comment didn't say they are
    wrong, just not justified.
       Their argument about assimilation of the surface temperature data doesn't work either.
    Your report shows that changes in input data (surface and satellite and sondes) affects
    the fields. So, how do they prove that their differences are due to urbanization and
    land-use changes and not data inputs. The differences between CRU and ERA-40 can
    hardly be said to be gradual. You've explained most of them by data input changes. The
    jumps with NCEP are larger and there are more of them.
       I'm here today and tomorrow then off next week. Back for the whole of June and
    July (except for a fortnight when the house move occurs). If you want to give me a
    call after June 1 then do. How soon can the report go to press?
      Also, do you intend to go to Geneva for GIP in August?
    Cheers
    Phil
   At 23:04 18/05/2004 +0100, you wrote:

     Ming, Eugenia
     I'm travelling also, and do not have a copy of your Nature paper with me.
     I have looked at Fig 16 however. It does show a rise in the NH in the difference between
     temperature at two metres and near the top of the boundary layer. But the rise occurs
     principally rather sharply in the first half of the 1990s, not what I would have
     expected from an affect of change in land-surface use, and it is seen also in the
     simulation, which did not have any change over time in prescribed land characteristics.
     Unless there is simply chance agreement between the simulation and the reanalysis I
     suspect that there is some effect from the SST/sea-ice analysis at play here.
     The plot corresponding to Fig 16 but restricted to North America is attached.
     Best regards
     Adrian
     cai wrote:

     Dear Adrian,
     Eugenia is on travel.  I am not sure if she would be able to check her email in time to
     response your
     email.  Anyhow, this is my response to two additional questions of yours, which follows
     after your
     original questions below.
     Regards.
     Ming Cai
     On May 17, 2004, at 5:46 PM, Adrian Simmons wrote:

     Dear Ming and Eugenia
     Thanks for your comments, which I'll take note of when I revise the text of our paper in
     a week or two.
     I am puzzled, though, by your second comment. I do not understand the reference to Fig
     6a, which does not relate to the trend above the boundary layer. The relevant figure is
     Fig12b,which shows a very similar trend over North America at the surface and at level
     49. The trend is a little lower at 500hPa (attached), but not much.
     I'd appreciate it if you could clarify this point.

     We meant Fig. 16 instead of Fig. 6 in our comment letter.  Looking at Fig. 12b or the
     figure you attached in your last email, I have to agree that the difference between
     ERA40 2 meter temperature and level 49 temperature indeed
     is small (I understand that the former is subject to the second tier assimilation and
     the latter results from  the primary data assimilation system.  This is indeed very
     impressive result).  However, if we look at the red curve in Fig. 16a, we do see the
     difference between the 2-meter temperature and level 49 temperature increases in time
     over NH.  From that plot, one can conclude that the 2-meter temperature warms at a fast
     rate than that at the level 49.  Perhaps, we didn't interpret that figure correctly.  I
     appreciate if you could help us to interpret that figure.

     Also, with regard to your fourth point, strictly speaking I did not write that our AMIP
     run argued against an effect of land-use change; I actually wrote that it did not
     support your conclusions. That was intended as a more netral comment, as one might
     indeed have reservations as to the conclusions one can draw from imperfect model
     simulations, just as one might have reservations about what can be deduced from
     imperfect reanalyses.

     Yes, we understand that that result is neutral in the context of our Nature paper is
     concerned.  However, if you put that result in the context of our Nature paper,
     particularly saying that it didn't not support
     our conclusion, that would make the result NOT "neutral", which is a concern of ours.

     Best regards
     Adrian
     cai wrote:

     Dear Adrian,
     Attached is our response to your manuscript.  Thanks again
     for sharing the manuscript with us.  We are looking forward to
     more discussion on this subject.
     Regards.
     Ming Cai
     On Apr 25, 2004, at 3:36 PM, Adrian Simmons wrote:

     Dear Ming
     Thanks for the response. Unfortunately I shall not be at the EGS meeting. I myself will
     be travelling from 6 to 21 May, but hope to check my email from time to time while away.
     I will not take our manuscript any further until I have heard from you and Eugenia, but
     would like at least to publish it as an ERA-40 report (with or without reference to your
     work) as soon as I get back.
     Best regards
     Adrian
     Ming Cai wrote:

     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.
     Regards.
     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.
     On Apr 23, 2004, at 5:53 PM, Eugenia Kalnay wrote:

     -------- Original Message --------
     Subject: Re: Paper on ERA-40/NCEP/CRU comparisons
     Date: Fri, 23 Apr 2004 22:30:07 +0100
     From: Adrian Simmons <Adrian.Simmons@ecmwf.int>
     Organization: E.C.M.W.F
     To: Eugenia Kalnay <ekalnay@atmos.umd.edu>
     References: <40894D36.2030005@ecmwf.int> <40897810.90705@atmos.umd.edu>
     Thanks for the initial response, Eugenia. I won't reply fully now, but
     will wait for your detailed comments.
     One thing though. I did note you replied to the comments in the
     references, but certainly could flag this in the text also. But let's
     see whether the references to your Nature letter survive at all. Maybe
     you'll convince me to say nothing.
     And a second. I show in the paper that the trace of temperatures over
     North America at model level 49 (about 850hPa for 1000hPa surface
     pressure) are virtually the same as at the surface. The level-49
     analysis is hardly affected at all by the fact we did a separate
     analysis of two-metre temperature using SYNOPS. There's just a weak
     affect at this level from the soil-moisture and soil-temperature
     analysis. Am I wrong to expect that land-use changes would affect
     near-surface temperatures but have less impact on temperatures at the
     top of the PBL?
     There's no chance of the paper being submitted for at least a month.
     I'll be wearing my computer-buying hat in the US and Japan before then.
     Best regards
     Adrian
     Eugenia Kalnay wrote:

     Dear Adrian:
     This is a very preliminary response, since my coauthor is away, and I would like to
     consult with him, and prepare a detailed response/comments, which we will send hopefully
     next week. I only gave your draft a very fast first reading.
     Nevertheless, I'll give you a first quick response:
     First I completely agree with you that ERA-40 should indeed be better than NNR! It
     better be!!!! So I don't have any quarrel with the results that you present. Hopefully
     the next global reanalysis will be even better...
     However, I think that your conclusions about the support or lack of support of your
     results to those of Kalnay and Cai (2003) are not appropriate or fair: Our method is
     *totally* based on the fact that the NNR surface temperature was completely independent
     of the observed surface temperature, which is evidently not true in the ERA-40, where
     the observed surface air temperatures did influence the soil temperature and moisture.
     Therefore, the only thing that you can conclude is that our method (unfortunately)
     cannot be applied "as is" to the ERA-40 reanalysis. For example, the fact that the NNR
     has a larger amplitude intra-annual variability is in agreement with the assumption that
     the NNR surface temperatures don't "know" about the increased heat capacity brought by
     land surface changes. Note also that we do not apply our method to the Rockies, since
     evidently the NNR surface temperature estimation is not good at all over regions with
     steep orography and cannot be used.
     Since you list the criticisms of Trenberth and Vose et al, it would be fair to quote as
     well our strong responses. (We first had to correct many serious errors of understanding
     that they made in their first critical comments). We have also received hundreds of very
     positive comments as well, and one very famous scientist here and his team did a very
     careful study over China with our method, with very similar results to ours, and with
     remarkable agreement between the land surface changes estimations from our method, and
     changes in population and agriculture.
     There are a number of other points that I would like to make, and Ming Cai will have
     many insightful comments as well... Thanks for showing this to us first... Please don't
     send it for publication until we clear out our disagreements, or at least agree to
     disagree...
     With warm regards,
     Eugenia
     Adrian Simmons wrote:

     Eugenia
     I'd appreciate any comments you might have on the attached draft, particularly the
     second paragraph of the introduction and the last paragraph of the conclusions. I take
     all the blame - the first the co-authors will see of these two paragraphs are when they
     respond to the mail below. I hope I have the story straight - I'm certainly open to
     changing it if not. I also hope that the paper in general does not come across as trying
     to "do down" the NCEP/NCAR reanalysis - ERA-40 is a much more recent reanalysis, and it
     would be strange if it did not improve on the NNR in some ways. Here again, I'm open to
     suggestions for changes in wording.
     Best regards
     Adrian
     -------- Original Message --------
     Subject: Paper on ERA-40/CRU comparisons
     Date: Fri, 23 Apr 2004 17:53:53 +0100
     From: Adrian Simmons <Adrian.Simmons@ecmwf.int>
     Reply-To: Adrian.Simmons@ecmwf.int
     Organization: ECMWF
     To: Phil Jones <p.jones@uea.ac.uk>,  ers@ecmwf.int,
     erp@ecmwf.int, Anton Beljaars <Anton.Beljaars@ecmwf.int>, Vanda Da Costa Bechtold
     <Vanda.Bechtold@ecmwf.int>,  Sami Saarinen <Sami.Saarinen@ecmwf.int>, Pedro Viterbo
     <Pedro.Viterbo@ecmwf.int>, Nils Wedi <Nils.Wedi@ecmwf.int>
     CC: dib@ecmwf.int
     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

     --
     --------------------------------------------------
     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
     --------------------------------------------------
     --
     Eugenia Kalnay
     Distinguished University Professor
     Department of Meteorology
     University of Maryland
     3431 CSS Building
     College Park, MD, 20742-2425
     tel: 301-405-5370/5391; fax:301-314-9482
     ekalnay@atmos.umd.edu; [1]http://www.atmos.umd.edu/~ekalnay
     Home: Malise Dick and Eugenia Kalnay <ekalnay@erols.com>
     56 Lakeside Dr
     Greenbelt MD 20770
     tel/fax 301-313-0208

     --
     --------------------------------------------------
     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
     --------------------------------------------------

     Ming Cai
     Associate Professor
     Department of Meteorology & School of   Computational Science and Information Technology
     Florida State University
     Tallahassee, FL 32036
     Email: cai@met.fsu.edu, cai@csit.fsu.edu
     Phone: (850)-645-1551, FAX: (850)-644-9642

     --
     --------------------------------------------------
     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
     --------------------------------------------------
     <response2simmons.pdf><temp.pdf>

     --
     --------------------------------------------------
     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    p.jones@uea.ac.uk
   NR4 7TJ
   UK
   ----------------------------------------------------------------------------

