date: Wed, 05 Nov 2003 09:55:49 +0000 from: Phil Jones subject: Fwd: Re: changes in the NH annual cycle to: t.osborn@uea.ac.uk,k.briffa@uea.ac.uk Date: Wed, 05 Nov 2003 09:29:10 +0000 To: Drew Shindell From: Phil Jones Subject: Re: changes in the NH annual cycle Drew, Apologies for the reference problem. Got the title off one of the reviewers (Mike Mann) ! Changed it in another article I'm doing with Mike - a review of paleo for Rev. Geophys. (submitted a few weeks ago). Mike has been spending too much time with that ridiculous paper - still I think even he has been worn down by everything ! We may do some more on the E&E paper but let things settle for a while. We won't be auditing it, but trying to do something that will also have some useful science in it. Mike may have made one or two small mistakes, but nothing major. Skeptics seem to think that if you try and shoot one paper down then the rest will fall. Several other groups (including us) have got pretty much the same result given the uncertainties. I'll forward an email from the editor of E&E - makes fun reading. Gavin and others might like to see it. Doesn't seem to grasp the concept of good science ! Seems to think we get results just because of who funds us - I just hope that this doesn't happen in other areas of science. The editor obviously has no idea how to write a paper, nor how hard it is to get proposals supported - we do have failed ones ! The European and Chinese regions are relatively small even in NH terms, but I would reckon that if I were to regress averages for these two areas against NH temps the result wouldn't be too bad. So, I think what you propose is eminently reasonable. It is what I would support - we suggest that seasonal cycles in models should be tested and we think that different forcings should be distinguishable by their seasonal signatures. Do you want me to send you the series that went into Figs 1 and 2 in the paper? I would produce three groups (one for China - the N and E areas are a bit of a misnomer, one is north of the other) and then one for N. Europe and one for C. Europe. N Europe could combine the Fennoscandian series with the Dutch/CET ones, then the other could use the Italian stations with the Swiss and Czech. N.China is 35-45N, 110-120E and E. China 30-35N, 115-120E. European sites/countries are basically what they say they are. You could get 3 European regions if you split the Dutch/CET series from Fennoscandia. C. Europe should involve the Swiss/Czech/Italian data. Apart from the Dutch series it is also possible to get the other 2 seasons as well. Spring will be OK, but for autumn there are generally few proxies, so this is the least good season for documentary data. Just reread your letter. Missed the last couple of sentences first time. I'll send the data and some details. Happy to work with you. Cheers Phil At 14:43 04/11/2003 -0500, you wrote: Hello Phil, I hope you had a good trip home from Spain, and haven't had to spend too much time dealing with the ridiculous Energy & Environment paper (I'm sure Mike's outraged, given his temperment!). I enjoyed your talk in San Feliu, and downloaded your JGR paper when I got home. I've read it through, and wanted to run an idea by you. In your Figure 2, you show six of the very long-term records, and in the text you point out that "warmer periods are associated with lower summer/winter differences". I thought it would be interesting to see if the model would reproduce such behavior and perhaps compare with the data you show. Now I noticed that you specifically mention that given the limited amount of data, it's not appropriate to form a composite. Given that China is quite large, the northern and eastern sites could be quite far apart, and there are only two sites in any case. So I fully agree that for nearly the entire globe there's too little data to create any reasonable averages. What I wonder is about using the four European sites in a comparison with the GCM simulations specifically for Europe (i.e. the rectangle including England and the 3 central European sites). This covers enough of the model domain that I believe we could get statistically significant results for the regional average temperature response to forcing, though I haven't done the calculation yet. Basically I would use the simulations described in our new J. Climate paper for solar and volcanic forcings. What I did do so far is to create the summer/winter differences, and they are of the opposite sign for the response to solar and volcanic forcing. I have the change in the annual cycle per change annual average from the model, which could be the most useful quantity. Given that the sign is opposite between the two forcings, this seem interesting to me, and conceivably we could make at least a qualitative comparison with the 4 proxy records and it would still be valuable. Qualitative would probably be the most appropriate in any case, given that there are only 4 proxy records and that the forcing time series, especially for solar, is not well-calibrated. Since the proxy data and the simulations are already published, I would envision simply a short analysis of the comparison between them. Do you think it'd be reasonable to use only 4 sites to in some sense represent regional European temperatures, and if so, would you be interested in providing the data from those 4 sites and/or in doing some analysis of this with me? Best wishes, Drew PS The reference to our J. Climate paper in your JGR has an incorrect title (Little Ice Age is too vague I feel). The paper is due out in the Dec 15 issue, and the full reference is: Shindell, D. T., G. A. Schmidt, R. L. Miller, and M. E. Mann, Volcanic and solar forcing of climate change during the preindustrial era, J. Climate, 16, 4094-4107, 2003. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Dr. Drew Shindell NASA-Goddard Institute for Space Studies 2880 Broadway New York, NY 10025 USA Tel/Fax: (212) 678-5561 email: dshindell@giss.nasa.gov [1]http://www.giss.nasa.gov/~dshindel/ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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 ---------------------------------------------------------------------------- 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 ----------------------------------------------------------------------------