Saturday, June 2, 2012


cc: Keith Briffa <>, Jonathan Overpeck <>, Eystein Jansen <>
date: Mon, 25 Jul 2005 13:04:40 -0400
from: Tom Crowley <>
subject: Re: MWP figure
to: Tim Osborn <>

Tim, go ahead and do it, don't forget all of these time series have been
published, all we did was take the published data and convert it to std.
deviation of decadally smoothed data, so even though my compilation is
still in our review in Nature, the basic data should not even be at that
stage, and in the supplementary section of the nature paper I think I
was fairly complete in describing what I did.

come to think of it, there is one exception, Jacoby only released
individual tree ring sites from Mongolia, not his annual avergae
composite, so I had to do a composite on that, splicing together
information from different sections of the various records - i spent
about a week on this but don't claim to have the final summary, would be
good if someone else did it too so we could compare notes - see.
attached [red X's signify the values of the final composite, different
colors represent different sections of the splice, with coded
annotations about which records were included in each section of the

hope this helps, tom

Tim Osborn wrote:

> At 17:54 21/07/2005, Tom Crowley wrote:
>> Tim, we are getting close but there are a few items to discuss:
> Hi Tom,
> I haven't seen any replies from Peck or Eystein, and Keith will be
> away all week because unfortunately his father has just died.
> So I guess it's down to us to make the final decisions. Here are my
> responses:
>> 1) seven of the eight time series are from the Hegerl et al paper,
>> now out for review in Nature
>> 2) the eighth time series is from Brian Luckmans recent extension of
>> the Alberta record to the 10th century - we used his original time
>> series in the H et al paper because the comparisons between model and
>> observations had been going on for a while, in fact before the new
>> Luckman paper came out, and we did not want to switch horses in
>> midstream by changing the composite - as you know the Luckman paper
>> is either accepted or published in CD, so there is no problem
>> changing that
>> 3) although technically the time series are not the same they are
>> very close, if you want me to do some comparisons I can, but I could
>> not get to it until probably tuesday of next week - I don't
>> particularly see any problem in makng such an addition
> I don't think this any comparisons are necessary. Even if they're not
> quite the same, they'll be close if 7/8 series are the same or
> similar. I think we should go with the 8 you've used in your figure.
>> 4) we cannot extend the time series back to 800 without dropping out
>> something - the reason we start at 945 is that is the first year when
>> all the records are available - if we go back to 800 we do so at the
>> cost of dropping 2 or possibly even 3 records. as our Dark Ages
>> reconstruction starting at 560 indicates (att.), the biggest warming
>> between 800-1900 is in the late 10the century (960-995), we did not
>> think we missing out on anything by starting at 945 rather than 800.
> good reason. so 945 onwards is fine.
> Are you happy for me to have these data series, so I can draw the
> final version of the figure? If there's any problem over restricted
> access, then I'm happy to guarantee that I'll only use them for this
> IPCC figure and not pass them on to anyone else.
> Best wishes
> Tim
> Dr Timothy J Osborn
> Climatic Research Unit
> School of Environmental Sciences, University of East Anglia
> Norwich NR4 7TJ, UK
> e-mail:
> phone: +44 1603 592089
> fax: +44 1603 507784
> web:
> sunclock:


Attachment Converted: "c:\documents and settings\tim osborn\my documents\eudora\attach\Mongolia.splice.jpg"

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