Saturday, March 31, 2012


cc: <>
date: Mon, 04 Feb 2008 13:28:59 +0000
from: Tim Osborn <>
subject: RE: wengen paper progress AND new position stating August
to: "Wahl, Eugene R" <>,<>

Hi Gene,

thanks for the useful feedback. I've incorporated all your edits and
additions and will insert the revised section back into Phil's master
document. I'll email Caspar about the few remaining issues related
to the figures.

Some further thoughts (for interest only, not for any further
modification of the text):

(1) re. the question of whether you can extract linear coefficients
relating individual proxies to individual temperatures for RegEM or
whether it is somehow non-linear due to the iterative
implementation. Well, I don't really know, so I've kept your
suggested text there. However, Jason Smerdon told me he had done the
extraction, though he didn't show me any results! Obviously the
coefficients would change with every change in proxy network and/or
temperature network. But if they were fixed, Jason says you can get
coefficients out of it. Mike M. wrote a similar thing about the
MBH98 method (i.e., that you couldn't get coefficients out of it) but
Gerd Burger told me that he had proven analytically that you
could. He showed me a page of algebra but no results to back it
up! So I really don't know what to think... an interesting question
to resolve later, I think.

(2) re. the question of quantitative evaluation/comparison of climate
fields and, perhaps more difficult still to reduce to a few metrics,
time series of fields. Yes, it is something I'm interested in
looking at in more detail and would be happy to do something together
on this, though time is tight for the next half year at least.

Congratulations on your forthcoming move to Boulder,



At 21:47 03/02/2008, Wahl, Eugene R wrote:
>Hi Tim, Phil, Keith:
>Attached is my go-over of entire chapter 3. [I didn't have a role
>in other chapters, so I didn't review those.]
>I essentially agreed with everything you did there, Tim, as you will
>see. I've added references here and there that I think should be
>included where inserted, but since my knowledge is not encyclopedic
>in the area (unfortunately, as it should be more full) there may be
>other references that appropriately should be included.
>I also included a couple sentences relating to pseudo-proxy
>experiments I did with the Luterbacher et al.-type TEOF field
>reconstruction method last August to prepare for the Beijing IMSC
>meeting -- the meeting where Caspar gave my talk for me. These
>results should be included, because they indicate that the canonical
>regression TEOF method L. et al. have used (pioneered in
>paleoclimatology by Hal Fritts) might perform about as well as RegEM
>under certain circumstances. This would be interesting, not least
>because the coefficients that are derived in this method directly
>give the relative contribution of each proxy PC to each retained
>instrumental PC. This kind of direct, easy-to-interpret output is
>useful, I think.
>I also added a little bit to clarify the wording about the
>interesting result that TEOF CFRs may reconstruct anomaly pattern
>spatial representations more robustly than they do the amplitudes of
>spatial means.
>I need to direct you to Caspar for the originals of the "too small"
>figures that I included. Alternatively, what about just blowing
>them up and using the larger versions, rather than the "postage stamp" ones?
>Thanks for your work, one and all.
>Peace, Gene
>From: []
>Sent: Sun 1/27/2008 10:28 PM
>To: Wahl, Eugene R
>Subject: RE: wengen paper progress AND new position stating August
> Gene,
> Congratulations on the new job with the paleo group
> in Boulder.
> I'm currently in Boulder at a meeting. I'll be here all
> the week and leave for home on Friday. Francis will be
> here as well. Caspar should be also. He's not on the IDAG
> group, but I think he's attending.
> I've been through what Tim has done and it looks OK.
> We're under a bit of pressure from Thorsten and Larry
> (PAGES and EPRI) to get this whole thing off. Next weekend
> will be fine though.
> The three of us in CRU will have a good go the first week of
> Feb. Keith still needs to add in the tree-ring bit.
> Keith's arranged with the Holocene to get the whole thing reviewed
> quickly, so we'll pick up time. It seems though that Larry
> wants something to justify his funding of the Wengen meeting.
> When looking at the draft next weekend, look also at the
> Figures you supplied. Most are OK, but if you can send the
> one that is a bit blurry - and most detailed in another format
> that would be good.
> Cheers
> Phil
> > Hi Tim (and Phil and Keith):
> >
> > Thanks, Tim, for the work on this. I've looked things over briefly, and
> > have booked time next weekend to get to it in earnest. It's quite a job
> > you've done to put all the pieces together.
> >
> > One question, and to Phil and Keith also, is whether you see/saw
> > significant difference between the results I'm reporting from my work with
> > Caspar and those reported by Francis and his co-workers. I will look for
> > this, of course, but want also to check with you. Caspar says he doesn't
> > think there should be any problem, but I'd also like your opinion. And,
> > of course, difference can be a good thing too...
> >
> > I'm sorry that I can't look at the text sooner, but we have a major event
> > going on here (and at 1200 other universities and colleges in the US) this
> > week. It is called "Focus the Nation", and is a major effort to stimulate
> > the political landscape to take climate change issues seriously --
> > especially with our presidential "primaries" going on, and a major number
> > of the state voting on Feb. 5. I am significantly involved in this as
> > Asst. Prof. of Environmental Studies, so my time is pretty limited for the
> > next 6 days.
> >
> >
> > Finally, you may have heard that I have accepted a scientist position with
> > the NOAA Paleoclimate Branch. I will be starting in August, after I
> > complete Spring term here at Alfred and have the chance to move and get
> > settled back in Colorado. I am excited to make this move, and have the
> > chance to do more significant focusing on my research than I've been able
> > to do during this academic year.
> >
> > Below is a copy of the e-announcement released by NOAA.
> >
> > Peace, Gene
> > -------- Original Message --------
> > Subject: New scientist at the Paleoclimatology Branch
> > Date: Thu, 10 Jan 2008 10:07:41 -0500
> > From: David Easterling <>
> > To: _NESDIS NCDC All /w PB & Contractors <>
> >
> > It is with pleasure that we announce that Dr. Gene Wahl currently
> > at Alfred University in NY has accepted our offer, and will join the
> > Paleoclimatology Branch in Boulder this coming August.
> > We are very lucky to have Gene join us. He is an expert in climate
> > reconstructions of the past millennium using tree rings and multi-proxy
> > data networks. He has pioneered new methods in this area, testified on
> > this topic for Congress, and participates in the PAGES focus on this
> > theme. Gene began his paleo career in palynology, and completed his PhD
> > on pollen analysis with Margaret Davis at the U. of Minn, one of the
> > pioneers of paleoecology. In this area he has worked with transfer
> > functions and analog techniques, methods relevant to all our fossil
> > count data. Finally, Gene brings expertise in the statistical analysis
> > of climate data, including new methods to compare paleoclimate and
> > model data, an area that will be of benefit not only in paleo but also to
> > the
> > Scientific Services Division and NCDC in general.
> >
> > --
> > David R. Easterling, Ph.D
> > Chief, Scientific Services Division
> > NOAA's National Climatic Data Center
> > 151 Patton Avenue
> > Asheville, NC 28801
> > V: +1 828 271 4675
> > F: +1 828 271 4328
> >
> >
> >
> > --
> > David M. Anderson
> > NOAA Paleoclimatology Branch Chief and Director, World Data Center for
> > Paleoclimatology
> > NOAA's National Climatic Data Center
> > 325 Broadway, E/CC23, Boulder, CO, 80305-3328
> > Tel: (303) 497-6237
> >
> >
> > ________________________________
> >
> > From: Tim Osborn []
> > Sent: Sat 1/26/2008 1:44 PM
> > To:;; Wahl, Eugene R;
> >
> > Cc:
> > Subject: wengen paper progress
> >
> >
> >
> > Hi Phil, Gene, Francis and Keith,
> >
> > I've now finished putting Gene's and Francis' contributios together with
> > some text of mine into section 3 of the "Wengen" paper. Everything has
> > been done with tracked changes so that you can follow (and undo if
> > necessary) what I've done.
> >
> > Gene -- this is the same as Friday's version except that I have now
> > continued from page 34 to the end of your contribution with a few further
> > suggested changes.
> >
> > Phil -- I've also had time to comment on the ice core section, so there
> > are some suggested edits there too.
> >
> > Francis -- your contribution forms section 3.4.1. I included the edits
> > that I had previously sent you... so please see my previous email if you
> > want to undo any of them. Is the Lee et al. paper out yet? If so, could
> > you send the full citation?
> >
> > Keith -- when you have time, I'd appreciate it if you could take a look at
> > the sections 3.2 and 3.3 that I added on CPS methods and on the
> > pseudo-proxy approach to see if they read ok.
> >
> > Cheers
> >
> > Tim
> >
> >
> >
> >
> >
> >

Dr Timothy J Osborn, Academic Fellow
Climatic Research Unit
School of Environmental Sciences
University of East Anglia
Norwich NR4 7TJ, UK

phone: +44 1603 592089
fax: +44 1603 507784


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