From	Jonathan T. Overpeck	Date	Tue, 28 Jun 2005 10:11:05 -0600
To	Keith Briffa
CC	Eystein Jansen
Subject	Re: Fwd: Re: updated MWP figure
Hi Keith - might be worth talking on the phone - you, me and Eystein - after you get back. You could be right, but it is a powerful way to look at the issue. The question is whether the normalization could be preventing a warmer than late-20th century signal from appearing? Should we instead update the Bradley Science graphic? That's not as effective in my opinion. So, let's talk next week? Going to a tree day meeting or a three day meeting - it has to be tough looking at tree data all day. have fun, thx, peck >Jonathan and Eystein >I am leaving very early for a tree day meeting in Swansea , and will >be away til Monday. Presently buried in EC Reporting and other stuff >- but the reason I dislike the MWP Figure is that the simple >normalization of series as done , (regardless of regional selection >of specific proxies) gives a largely random amplitude to the various >records , depending on their spectral character, and of course, >equal weight to all regardless of the strength of their link with >local or NH temperatures). I will think about this - you are the >ultimate arbiter anyway . >sorry to be so abruptly communicative >Keith > >At 16:10 28/06/2005, you wrote: >>Hi Tom -- thanks for the extra effort. I'm pushing others on the >>author team to think hard about such a figure (space may end up >>being the hardest part), and I should have something to discuss w/ >>you soon. Thanks for being willing to shift priorities if needed. >> >>FYI - I just got reviews back from an EOS piece that took over a >>1.5 months to get. And of course, they want some edits. Not the >>speedy venue we once knew a loved, although I bet if you really >>keep it short and sweet it might go faster. >> >>Best, more soon, peck >> >>>X-Sieve: CMU Sieve 2.2 >>>Date: Tue, 28 Jun 2005 10:13:49 -0400 >>>From: Tom Crowley >>>X-Accept-Language: en-us, en >>>To: Jonathan Overpeck >>>Cc: Eystein Jansen >>>Subject: Re: updated MWP figure >>> >>>Hi Jonathan, >>> >>>let me answer the last question first - there are actually not >>>many records that go back that far and I have used, I think, every >>>one except Quelcaya, which being from the southern tropics makes >>>for a lonely but potential future inclusion (which makes no >>>difference on the conclusion). >>> >>>several of the sites include multiple time series - e.g., western >>>U.S. time series, w. Siberia time series, e. Asia, and w. >>>Greenland. I did not want to overweight any site though because >>>of the need for a geographic balance -- note that there are four >>>sites each in the w. hemisphere and e. hemisphere, and that the >>>distribution of sites in each hemisphere represents a good scatter. >>> >>>for almost all of these sites the references are easily imaginable >>>based on the location of the site, but they can be provided if you >>>are interested in including the figure. >>> >>>can you think of any long sites I have not included? right now I >>>cannot..... >>> >>>in the overlap interval of 1500-1850 our composite has highly >>>significant correlations with the Mann, Jones, and Briffa >>>reconstructions that contain much more data -- thereby suggesting >>>that use of only long time series provides a "reasonable" estimate >>>of the last 1100 years. >>> >>>I have not submitted this for publication but if you are >>>interested in including this in ipcc I can knock off a tutorial >>>note to eos on short notice..... >>> >>>I am attaching the figure in several different alternate formats - >>>cannot easily do the two you suggest from my mac, but again I can >>>get that done with more work if you are interested - let me know >>>where to go next - note that I originally sent this along fyi, >>>only to be used if you thought the figure was worthwhile -- if not >>>I will just reorder the priority of writing it up as a note, >>>tom >>> >>>Jonathan Overpeck wrote: >>> >>>>Hi Tom - thanks for sending this plot. I'm a bit late in >>>>responding since we were moving to (and still into) our >>>>sabbatical digs in SW CO. >>>> >>>>Would you be willing to provide more on this plot in order for me >>>>to understand it better? I personally like the plot quite a bit, >>>>but between the space restrictions and other's assessment, >>>>whether we use it or not will take some real thinking. >>>> >>>>For example, it would help to have >>>> >>>>1) a higher resolution version - eps or ai? >>>>2) a caption or text that would spell out which records are >>>>included, and their origins (references) >>>>3) a bibliography for those refs. >>>>4) perhaps, you have a paper with this included? If so, can you >>>>send a prerprint? >>>>5) some discussion of why you used the series (sites) you did, >>>>and not others - more specifically, what's wrong with others? >>>> >>>>If you don't mind helping here, I'll promise to get it in the mix >>>>for serious discussion. Of course, it's already in the mix since >>>>Eystein forwarded to Keith, and you Tim, but I want to weigh in >>>>as informed as possible. Trying to keep track of a lot, so your >>>>help is much appreciated. >>>> >>>>Thanks! Peck >>>> >>>>>Hello, >>>>> >>>>>I have been fiddling with the best way to illustrate the stable >>>>>nature of the medieval warm period - the attached plot has eight >>>>>sites that go from 946-1960 in decadal std. dev. units - >>>>>although small in number there is a good geographic spread -- >>>>>four are from the w. hemisphere, four from the east. I also >>>>>plot the raw composite of the eight sites and scale it to the >>>>>30-90N decadal temp. record. >>>>> >>>>>this record illustrates how the individual sites are related to >>>>>the composite and also why the composite has no dramatically >>>>>warm MWP -- there is no dramatically warm clustering of the >>>>>individual sites. >>>>> >>>>>use or lose as you wish, tom >>>>> >>>> >>>> >>> >>> >>> >>> >> >> >>-- >>Jonathan T. Overpeck >>Director, Institute for the Study of Planet Earth >>Professor, Department of Geosciences >>Professor, Department of Atmospheric Sciences >> >>Mail and Fedex Address: >> >>Institute for the Study of Planet Earth >>715 N. Park Ave. 2nd Floor >>University of Arizona >>Tucson, AZ 85721 >>direct tel: +1 520 622-9065 >>fax: +1 520 792-8795 >>http://www.geo.arizona.edu/ >>http://www.ispe.arizona.edu/ >> >> >> > >-- >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/ -- Jonathan T. Overpeck Director, Institute for the Study of Planet Earth Professor, Department of Geosciences Professor, Department of Atmospheric Sciences Mail and Fedex Address: Institute for the Study of Planet Earth 715 N. Park Ave. 2nd Floor University of Arizona Tucson, AZ 85721 direct tel: +1 520 622-9065 fax: +1 520 792-8795 http://www.geo.arizona.edu/ http://www.ispe.arizona.edu/