From	Ben Santer	Date	Thu, 10 Jul 2008 13:56:40 -0700
To	Phil Jones
Subject	Re: [Fwd: JOC-08-0098.R1 - Decision on Manuscript]
Dear Phil, The wedding was really very moving and beautiful. I had a great time. I'm sending along a picture of Tom and Helen which was taken at Granite Island (near Victor Harbor). I don't know whether I've ever seen Tom as happy as he is now... Myles (if it is Myles) was a bit pedantic in his second review. Karl (who is a very-mild-mannered guy) described the tone of the review as "whining". It seems like the Reviewer was saying, "I'm a lot smarter than you, and I could do all of this stuff much better than you've done". I was very unhappy about the "wilfully ignoring" bit. That was completely uncalled for. Have a great time at Lake Constance, Phil. It's a beautiful part of the world. Best regards, and best wishes to Ruth, Ben P.Jones@uea.ac.uk wrote: > Ben, > Will read the comments in detail tomorrow, when at CRU. > I presume the wedding went well and a good time was had > by all. > > I'm in CRU tomorrow, but away next week. I'm off to one > your old hunting grounds - Friedrichshafen. I am going to > a summer school on the other side of the Lake near Konstanz. > Can't recall the village name - somthing like Treffpunkt. > > Only gone a week, back Friday week. > > From a quick scan below Myles does seem to be a pain! > As we both know he can be. > > Cheers > Phil > > >> Dear folks, >> >> I just returned from my trip to Australia - I had a great time there. >> Now (sadly) it's back to the reality of Douglass et al. I'm forwarding >> the second set of comments from the two Reviewers. As you'll see, >> Reviewer 1 was very happy with the revisions we've made to the paper. >> Reviewer 2 was somewhat crankier. The good news is that the editor >> (Glenn McGregor) will not send the paper back to Reviewer 2, and is >> requesting only minor changes in response to the Reviewer's comments. >> >> Once again, Reviewer 2 gets hung up on the issue of fitting higher-order >> autoregressive models to the temperature time series used in our paper. >> As noted in our response to the Reviewer, this is a relatively minor >> technical point. The main point is that we include an estimate of the >> standard error of the observed trend. DCPS07 do not, which is the main >> error in their analysis. >> >> In calculating modeled and observed standard errors, we assume an AR-1 >> model of the regression residuals. This assumption is not unreasonable >> for many meteorological time series. We and others have made it in a >> number of previous studies. >> >> Reviewer 2 would have liked us to fit higher-order autoregressive models >> to the T2, T2LT, and TS-T2LT time series. This is a difficult business, >> particularly given the relatively short length of the time series >> available here. There is no easy way to reliably estimate the parameters >> of higher-order AR models from 20 to 30 years of data. The same applies >> to reliable estimation of the spectral density at frequency zero (since >> we have only 2-3 independent samples for estimating the spectral density >> at frequency zero). Reviewer 2's comments are not particularly relevant >> to the specific problem we are dealing with here. >> >> It's also worth mentioning that use of higher-order AR models for >> estimating trend standard errors would likely lead to SMALLER effective >> sample sizes and LARGER standard errors, thus making it even more >> difficult to find significant differences between modelled and observed >> trends! Our use of an AR-1 model makes it easier for us to obtain >> "DCPS07-like" results, and to find significant differences between >> modelled and observed trends. DCPS cannot claim, therefore, that our >> test somehow stacks the deck in favor of obtaining a non-significance >> trend difference - which they might claim if we used a >> (poorly-constrained) higher-order AR model for estimating standard >> errors. >> >> The Reviewer does not want to "see the method proposed in this paper >> become established as the default method of estimating standard errors >> in climatological time series". We do not claim universal applicability >> of our approach. There may well be circumstances in which it is more >> appropriate to use higher-order AR models in estimating standard errors. >> I'd be happy to make a statement to this effect in the revised paper. >> >> I have to confess that I was a little ticked off by Reviewer 2's >> comments. The bit about "wilfully ignoring" time series literature was >> uncalled for. Together with my former MPI colleague Wolfgang >> Brueggemann, I've fooled around with a lot of different methods of >> estimating standard errors, in both the time domain and frequency >> domain. One could write a whole paper on this subject alone. Such a >> paper would not help us to expose the statistical deficiencies in >> DCPS07. Nor would in-depth exploration of this issue lead to the shorter >> paper requested by the Reviewer. >> >> It should take me a few days to revise the paper and draft a response to >> Reviewer 2's comments. I'll send you the revised paper and draft >> response early next week. Slowly but surely, we are getting there! >> >> With best regards, >> >> Ben >> ---------------------------------------------------------------------------- >> Benjamin D. Santer >> Program for Climate Model Diagnosis and Intercomparison >> Lawrence Livermore National Laboratory >> P.O. Box 808, Mail Stop L-103 >> Livermore, CA 94550, U.S.A. >> Tel: (925) 422-3840 >> FAX: (925) 422-7675 >> email: santer1@llnl.gov >> ---------------------------------------------------------------------------- >> >> > > > -- ---------------------------------------------------------------------------- Benjamin D. Santer Program for Climate Model Diagnosis and Intercomparison Lawrence Livermore National Laboratory P.O. Box 808, Mail Stop L-103 Livermore, CA 94550, U.S.A. Tel: (925) 422-3840 FAX: (925) 422-7675 email: santer1@llnl.gov ---------------------------------------------------------------------------- Attachment Converted: "c:\eudora\attach\DSCN2786.JPG"