From: Jonathan Overpeck <jto@u.arizona.edu>
To: Keith Briffa <k.briffa@uea.ac.uk>
Subject: Re: Fwd: Re: updated MWP figure
Date: Tue, 28 Jun 2005 10:11:05 -0600
Cc: Eystein Jansen <eystein.jansen@geo.uib.no>

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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 <tcrowley@duke.edu>
>>>X-Accept-Language: en-us, en
>>>To: Jonathan Overpeck <jto@u.arizona.edu>
>>>Cc: Eystein Jansen <eystein.jansen@geo.uib.no>
>>>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/
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