From: "Michael E. Mann" To: Keith Briffa Subject: Re: [Fwd: Re: GKSS results] Date: Thu, 19 Oct 2006 08:44:44 -0400 Reply-to: mann@psu.edu Hi Keith, Certainly not, and sorry for not clarifying. This is the response to the J. Climate comment by Von Storch that we're talking about here. The final draft is due this week, and so that's why I needed to check if you & Tim wanted co-authorship if we were going to show the GKSS result. We can certainly plan to do a more detailed followup analysis jointly, I would very much enjoy that. Something we've talked about doing is a set of experiments with "mixed proxies" where the proxies have a variable combination of surface temperature and precip components--it will be very interesting to see what happens in these cases. Perhaps this would be a good opportunity for collaboration, where we could apply this to several different models including CSM and the models you guys are working with? let me know what you think. thanks, mike Keith Briffa wrote: > Great Mike - but hope this does not mean that you will exclude our > possible contribution to this paper > Keith > > At 13:52 18/10/2006, you wrote: > >> thanKs Tim. As luck would have it, zorita is providing the data to >> Caspar anyway so this should now be a moot point. We'll keep you guys >> updated on things, >> Mike >> >> -----Original Message----- >> >> From: Tim Osborn >> Subj: Re: [Fwd: Re: GKSS results] >> Date: Wed Oct 18, 2006 3:37 am >> Size: 6K >> To: mann@psu.edu, Scott Rutherford >> cc: Keith Briffa >> >> Hi Mike, your suggested compromise is acceptable to both Keith and >> me. Good luck with the J. Clim. response. Cheers, Tim >> >> At 17:04 13/10/2006, Michael E. Mann wrote: >> >Keith, >> > >> >I also figured this might be what you say, and I understand where >> >you've coming from. This represents a bit of a dillemma too, as it >> >seems unprofessional at best that Zorita and Von Storch have not >> >made their code public, when we of course have made ours public. >> > >> >There are other sources where we could have gotten the GKSS >> >data--I'm checking w/ Caspar for confirmation. I know that the Cane >> >group has it, and I believe other groups have it nows too. So >> >frankly, it is effectively now 'public domain' whether VS and Zorita >> >like it or not! >> > >> >I propose, hoping that their is no loud objection, that we will >> >include a line in our response indicating that we have confirmed >> >that we get similar results using the GKSS Erik simulation. We'll >> >leave it at that. We don't need to show that result necessarily, >> >unless the editor/reviewers demand to see proof, and we certaintly >> >don't have to reveal where we got the GKSS data. As I mentioned, >> >there are enough groups out there that now have it, that VS and >> >Zorita would not know the source, and we would not reveal it. >> > >> >We feel as if we cannot completely hide the fact that we have >> >confirmed our result w/ GKSS, hence the "compromise" suggested >> >above. Meanwhile, we can pursue a more thorough, official >> >collaborative effort in the future. >> > >> >Thoughts on this? >> > >> >thanks, >> > >> >mike >> > >> >-- >> >Michael E. Mann >> >Associate Professor >> >Director, Earth System Science Center (ESSC) >> > >> >Department of Meteorology Phone: (814) 863-4075 >> >503 Walker Building FAX: (814) 865-3663 >> >The Pennsylvania State University email: mann@psu.edu >> >University Park, PA 16802-5013 >> > >> >http://www.met.psu.edu/dept/faculty/mann.htm >> > >> > >> > >> > >> >Return-Path: >> >X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on >> mail.meteo.psu.edu >> >X-Spam-Level: >> >X-Spam-Status: No, score=-2.6 required=5.0 tests=AWL,BAYES_00 >> autolearn=ham >> > version=3.1.3 >> >X-Original-To: mann@meteo.psu.edu >> >Delivered-To: mann@meteo.psu.edu >> >Received: from tr12n05.aset.psu.edu (tr12g05.aset.psu.edu >> [128.118.146.135]) >> > by mail.meteo.psu.edu (Postfix) with ESMTP id 08C5B204B4A >> > for ; Fri, 13 Oct 2006 11:51:52 -0400 >> (EDT) >> >Received: from mailgate5.uea.ac.uk (mailgate5.uea.ac.uk >> [139.222.130.185]) >> > by tr12n05.aset.psu.edu (8.13.6/8.13.2) with ESMTP id >> k9DFpkiX2199660 >> > for ; Fri, 13 Oct 2006 11:51:49 -0400 >> >Received: from [139.222.130.167] (helo=ueams2.uea.ac.uk) >> > by mailgate5.uea.ac.uk with esmtp (Exim 4.50) >> > id 1GYP3d-0000kt-V7 >> > for mann@psu.edu; Fri, 13 Oct 2006 16:34:50 +0100 >> >Received: from [139.222.104.74] (helo=angara.uea.ac.uk) >> > by ueams2.uea.ac.uk with esmtp (Exim 4.51) >> > id 1GYP3d-00037Y-JU; Fri, 13 Oct 2006 16:34:45 +0100 >> >Message-Id: <7.0.0.16.0.20061013163526.03552e98@uea.ac.uk> >> >X-Mailer: QUALCOMM Windows Eudora Version 7.0.0.16 >> >Date: Fri, 13 Oct 2006 16:36:51 +0100 >> >To: mann@psu.edu >> >From: Keith Briffa >> >Subject: Re: GKSS results >> >Cc: Tim Osborn >> >In-Reply-To: <452BCB6C.1070306@meteo.psu.edu> >> >References: <452BCB6C.1070306@meteo.psu.edu> >> >Mime-Version: 1.0 >> >Content-Type: multipart/mixed; >> > boundary="=====================_48573031==_" >> >X-UEA-Spam-Score: -102.8 >> >X-UEA-Spam-Level: --------------------------------------------------- >> >X-UEA-Spam-Flag: NO >> >X-Virus-Scanned: amavisd-sophos >> >X-PSU-Spam-Flag: NO >> >X-PSU-Spam-Hits: -2.599 >> > >> >Mike >> >Tim and I have discussed this round and round and our response is >> attached >> > >> >what do you think >> > >> >best wishes Keith >> > >> >At 17:33 10/10/2006, you wrote: >> >>Dear Tim/Keith, >> >> >> >>I hope all is well with both of you. >> >> >> >>We've been doing a number of sensitivity tests w/ RegEM using both >> >>the CSM simulation, and now more recently the GKSS simulation data >> >>we got from you. There are some methodological developments we'll >> >>describe soon, related to what is the most reliable regularization >> >>method in RegEM, ridge regression and truncated total least >> >>squares. We are now leaning towards the latter because of potential >> >>non-convergence problems in some cases w/ the former. More on that >> soon. >> >> >> >>More relevant, however, are the results. As you can see from the >> >>attached plot, RegEM works quite well w/ GKSS, using a short >> >>calibration period (1900-1980, corresponding to years 900-980 in >> >>the attached plot) and both white and red pseudoproxy noise (we >> >>used rho=0.5 in the attached, but similar result for other values). >> >> >> >>The most interesting result is that while RegEM reconstructs the >> >>full NH series well throughout, in the case of the CSM simulation, >> >>it does modestly underestimate the warmth of the earliest centuries >> >>in the GKSS Erik simulation (it fits everything else, including >> >>the LIA cooling, very well). We feel that this is likely due to >> >>problem of correctly identifying the 'drift' pattern using CFR >> methods. >> >> >> >>The long and short of this is that we would like to be able to show >> >>this result in a (very short!) J. Climate response we need to >> >>finalize, to a comment on Mann et al (2005) J. Clim by Zorita and >> >>Von Storch. We would show you this response for comment of course, >> >>and would add you as co-authors. We have cleared with Andrew Weaver >> >>that this would be an acceptable course of action. We are hoping >> >>you are in agreement with this? >> >> >> >>please let us know ASAP, we have to finalize our response within days. >> >> >> >>thanks, >> >> >> >>mike >> >> >> >>-- >> >>Michael E. Mann >> >>Associate Professor >> >>Director, Earth System Science Center (ESSC) >> >> >> >>Department of Meteorology Phone: (814) 863-4075 >> >>503 Walker Building FAX: (814) 865-3663 >> >>The Pennsylvania State University email: mann@psu.edu >> >>University Park, PA 16802-5013 >> >> >> >>http://www.met.psu.edu/dept/faculty/mann.htm >> >> >> >> >> >> >> > >> >-- >> >Professor Keith Briffa, >> >Climatic Research Unit >> >University of East Anglia >> >Norwich, NR4 7TJ, U.K. >> > >> >Phone: +44-1603-593909 >> >Fax: +44-1603-507784 >> > >> >http://www.cru.uea.ac.uk/cru/people/briffa/ >> >> Dr Timothy J Osborn, Academic Fellow >> Climatic Research Unit >> School of Environmental Sciences >> University of East Anglia >> Norwich NR4 7TJ, UK >> >> e-mail: t.osborn@uea.ac.uk >> phone: +44 1603 592089 >> fax: +44 1603 507784 >> web: http://www.cru.uea.ac.uk/~timo/ >> sunclock: http://www.cru.uea.ac.uk/~timo/sunclock.htm > > > -- > Professor Keith Briffa, > Climatic Research Unit > University of East Anglia > Norwich, NR4 7TJ, U.K. > > Phone: +44-1603-593909 > Fax: +44-1603-507784 > > http://www.cru.uea.ac.uk/cru/people/briffa/ -- Michael E. Mann Associate Professor Director, Earth System Science Center (ESSC) Department of Meteorology Phone: (814) 863-4075 503 Walker Building FAX: (814) 865-3663 The Pennsylvania State University email: mann@psu.edu University Park, PA 16802-5013 http://www.met.psu.edu/dept/faculty/mann.htm