The below are part of a series of alleged emails from the Climate Research Unit at the University of East Anglia, released on 20 November 2009.
Original Filename: 1051156418.txt | Return to the index page | Permalink | Later Emails
From: Tom Wigley <wigley@xxxxxxxxx.xxx>
To: Tom Wigley <wigley@xxxxxxxxx.xxx>, Phil Jones <p.jones@xxxxxxxxx.xxx>, Mike Hulme <m.hulme@xxxxxxxxx.xxx>, Keith Briffa <k.briffa@xxxxxxxxx.xxx>, James Hansen <jhansen@xxxxxxxxx.xxx>, Danny Harvey <harvey@xxxxxxxxx.xxx>, Ben Santer <santer1@xxxxxxxxx.xxx>, Kevin Trenberth <trenbert@xxxxxxxxx.xxx>, Robert wilby <rob.wilby@xxxxxxxxx.xxx>, "Michael E. Mann" <mann@xxxxxxxxx.xxx>, Tom Karl <Thomas.R.Karl@xxxxxxxxx.xxx>, Steve Schneider <shs@xxxxxxxxx.xxx>, Tom Crowley <tcrowley@xxxxxxxxx.xxx>, jto <jto@u.arizona.edu>, "simon.shackley" <simon.shackley@xxxxxxxxx.xxx>, "tim.carter" <tim.carter@xxxxxxxxx.xxx>, "p.martens" <p.martens@xxxxxxxxx.xxx>, "peter.whetton" <peter.whetton@xxxxxxxxx.xxx>, "c.goodess" <c.goodess@xxxxxxxxx.xxx>, "a.minns" <a.minns@xxxxxxxxx.xxx>, Wolfgang Cramer <Wolfgang.Cramer@xxxxxxxxx.xxx>, "j.salinger" <j.salinger@xxxxxxxxx.xxx>, "simon.torok" <simon.torok@xxxxxxxxx.xxx>, Mark Eakin <mark.eakin@xxxxxxxxx.xxx>, Scott Rutherford <srutherford@xxxxxxxxx.xxx>, Neville Nicholls <n.nicholls@xxxxxxxxx.xxx>, Ray Bradley <rbradley@xxxxxxxxx.xxx>, Mike MacCracken <mmaccrac@xxxxxxxxx.xxx>, Barrie Pittock <Barrie.Pittock@xxxxxxxxx.xxx>, Ellen Mosley-Thompson <thompson4@xxxxxxxxx.xxx>, "pachauri@xxxxxxxxx.xxx" <pachauri@xxxxxxxxx.xxx>, "Greg.Ayers" <Greg.Ayers@xxxxxxxxx.xxx>
Subject: My turn
Date: Wed, 23 Apr 2003 23:53:xxx xxxx xxxx
Dear friends,
[Apologies to those I have missed who have been part of this email
exchange -- although they may be glad to have been missed]
I think Barrie Pittock has the right idea -- although there are some
unique things about this situation. Barrie says ....
(1) There are lots of bad papers out there
(2) The best response is probably to write a 'rebuttal'
to which I add ....
(3) A published rebuttal will help IPCC authors in the 4AR.
____________________
Let me give you an example. There was a paper a few years ago by Legates
and Davis in GRL (vol. 24, pp. 2xxx xxxx xxxx, 1997) that was nothing more
than a direct
and pointed criticism of some work by Santer and me -- yet neither of us
was asked to review the paper. We complained, and GRL admitted it was
poor judgment on the part of the editor. Eventually (> 2 years later)
we wrote a response (GRL 27, 2xxx xxxx xxxx, 2000). However, our response was
more that just a rebuttal, it was an attempt to clarify some issues on
detection. In doing things this way we tried to make it clear that the
original Legates/Davis paper was an example of bad science (more
bluntly, either sophomoric ignorance or deliberate misrepresentation).
Any rebuttal must point out very clearly the flaws in the original
paper. If some new science (or explanations) can be added -- as we did
in the above example -- then this is an advantage.
_____________________________
There is some personal judgment involved in deciding whether to rebut.
Correcting bad science is the first concern. Responding to unfair
personal criticisms is next. Third is the possible misrepresentation of
the results by persons with ideological or political agendas. On the
basis of these I think the Baliunas paper should be rebutted by persons
with appropriate expertise. Names like Mann, Crowley, Briffa, Bradley,
Jones, Hughes come to mind. Are these people willing to spend time on
this?
_______________________________
There are two other examples that I know of where I will probably be
involved in writing a response.
The first is a paper by Douglass and Clader in GRL (vol. 29, no. 16,
10.1029/2002GL015345, 2002). I refereed a virtually identical paper for
J. Climate, recommending rejection. All the other referees recommended
rejection too. The paper is truly appalling -- but somehow it must have
been poorly reviewed by GRL and slipped through the net. I have no
reason to believe that this was anything more than chance. Nevertheless,
my judgment is that the science is so bad that a response is necessary.
The second is the paper by Michaels et al. that was in Climate Research
(vol. 23, pp. 1
Original Filename: 1051202354.txt | Return to the index page | Permalink | Later Emails
From: "Michael E. Mann" <mann@xxxxxxxxx.xxx>
To: mark.eakin@xxxxxxxxx.xxx
Subject: Re: My turn
Date: Thu, 24 Apr 2003 12:39:xxx xxxx xxxx
Cc: Tom Wigley <wigley@xxxxxxxxx.xxx>, Phil Jones <p.jones@xxxxxxxxx.xxx>, Mike Hulme <m.hulme@xxxxxxxxx.xxx>, Keith Briffa <k.briffa@xxxxxxxxx.xxx>, James Hansen <jhansen@xxxxxxxxx.xxx>, Danny Harvey <harvey@xxxxxxxxx.xxx>, Ben Santer <santer1@xxxxxxxxx.xxx>, Kevin Trenberth <trenbert@xxxxxxxxx.xxx>, Robert wilby <rob.wilby@xxxxxxxxx.xxx>, Tom Karl <Thomas.R.Karl@xxxxxxxxx.xxx>, Steve Schneider <shs@xxxxxxxxx.xxx>, Tom Crowley <tcrowley@xxxxxxxxx.xxx>, jto <jto@u.arizona.edu>, "simon.shackley" <simon.shackley@xxxxxxxxx.xxx>, "tim.carter" <tim.carter@xxxxxxxxx.xxx>, "p.martens" <p.martens@xxxxxxxxx.xxx>, "peter.whetton" <peter.whetton@xxxxxxxxx.xxx>, "c.goodess" <c.goodess@xxxxxxxxx.xxx>, "a.minns" <a.minns@xxxxxxxxx.xxx>, Wolfgang Cramer <Wolfgang.Cramer@xxxxxxxxx.xxx>, "j.salinger" <j.salinger@xxxxxxxxx.xxx>, "simon.torok" <simon.torok@xxxxxxxxx.xxx>, Scott Rutherford <srutherford@xxxxxxxxx.xxx>, Neville Nicholls <n.nicholls@xxxxxxxxx.xxx>, Ray Bradley <rbradley@xxxxxxxxx.xxx>, Mike MacCracken <mmaccrac@xxxxxxxxx.xxx>, Barrie Pittock <Barrie.Pittock@xxxxxxxxx.xxx>, Ellen Mosley-Thompson <thompson.4@xxxxxxxxx.xxx>, "pachauri@xxxxxxxxx.xxx" <pachauri@xxxxxxxxx.xxx>, "Greg.Ayers" <Greg.Ayers@xxxxxxxxx.xxx>, wuebbles@xxxxxxxxx.xxx, christopher.d.miller@xxxxxxxxx.xxx, mann@xxxxxxxxx.xxx
<x-flowed>
HI Mark,
Thanks for your comments, and sorry to any of you who don't wish to receive
these correspondances...
Indeed, I have provided David Halpern with a written set of comments on the
offending paper(s) for internal use, so that he was armed w/ specifics as
he confronts the issue within OSTP. He may have gotten additional comments
from other individuals as well--I'm not sure. I believe that the matter is
in good hands with Dave, but we have to wait and see what happens. In any
case, I'd be happy to provide my comments to anyone who is interested.
I think that a response to "Climate Research" is not a good idea. Phil and
I discussed this, and agreed that it would be largely unread, and would
tend to legitimize a paper which many of us don't view as having passed
peer review in a legitimate manner. On the other hand, the in prep. review
articles by Jones and Mann (Rev. Geophys.), and Bradley/Hughes/Diaz
(Science) should go along way towards clarification of the issues (and, at
least tangentially, refutation of the worst of the claims of Baliunas and
co). Both should be good resources for the FAR as well...
cheers,
mike
p.s. note the corrections to some of the emails in the original
distribution list.
At 09:27 AM 4/24/xxx xxxx xxxx, Mark Eakin wrote:
>At this point the question is what to do about the Soon and Baliunas
>paper. Would Bradley, Mann, Hughes et al. be willing to develop and
>appropriate rebuttal? If so, the question at hand is where it would be
>best to direct such a response. Some options are:
>
>1) A rebuttal in Climate Research
>2) A rebuttal article in a journal of higher reputation
>3) A letter to OSTP
>
>The first is a good approach, as it keeps the argument to the level of the
>current publication. The second would be appropriate if the Soon and
>Baliunas paper were gaining attention at a more general level, but it is
>not. Therefore, a rebuttal someplace like Science or Nature would
>probably do the opposite of what is desired here by raising the attention
>to the paper. The best way to take care of getting better science out in a
>widely read journal is the piece that Bradley et al. are preparing for
>Nature. This leaves the idea of a rebuttal in Climate Research as the
>best published approach.
>
>A letter to OSTP is probably in order here. Since the White House has
>shown interest in this paper, OSTP really does need to receive a measured,
>critical discussion of flaws in Soon and Baliunas' methods. I agree with
>Tom that a noted group from the detection and attribution effort such as
>Mann, Crowley, Briffa, Bradley, Jones and Hughes should spearhead such a
>letter. Many others of us could sign on in support.
>This would provide Dave Halpern with the ammunition he needs to provide
>the White House with the needed documentation that hopefully will dismiss
>this paper for the slipshod work that it is. Such a letter could be
>developed in parallel with a rebuttal article.
>
>I have not received all of the earlier e-mails, so my apologies if I am
>rehashing parts of the discussion that might have taken place elsewhere.
>
>Cheers,
>Mark
>
>
>
>Michael E. Mann wrote:
>
>>Dear Tom et al,
>>
>>Thanks for comments--I see we've built up an impressive distribution list
>>here!
>>
>>This seemed like an appropriate point for me to chime in here. By in
>>large, I agree w/ Tom's comments (and those of Barrie's as well). A
>>number of us have written reviews and overviews of this topic during the
>>past couple years. There has been a lot of significant scientific process
>>in this area (both with regard to empirical "climate reconstruction" and
>>in the area of model/data comparison), including, in fact, detection
>>studies along the lines of what Barrie Pittock asked about in a previous
>>email (see. e.g. Tom Crowley's Science article from 2000). Phil Jones and
>>I are in the process of writing a review article for /Reviews of
>>Geophysics/ which will, among other things, dispel the most severe of the
>>myths that some of these folks are perpetuating regarding past climate
>>change in past centuries. My understanding is that Ray Bradley, Malcolm
>>Hughes, and Henry Diaz are working, independently, on a solicited piece
>>for /Science/ on the "Medieval Warm Period".
>>Many have simply dismissed the Baliunas et al pieces because, from a
>>scientific point of view, they are awful--that is certainly true. For
>>example, Neville has pointed out in a previous email, that the standard
>>they applied for finding "a Medieval Warm Period" was that a particular
>>proxy record exhibit a 50 year interval during the period AD xxx xxxx xxxx
>>that was anomalously *warm*, *wet*, or *dry* relative to the "20th
>>century" (many of the proxy records don't really even resolve the late
>>20th century!) could be used to define an "MWP" anywhere one might like
>>to find one. This was the basis for their press release arguing for a
>>"MWP" that was "warmer than the 20th century" (a non-sequitur even from
>>their awful paper!) and for their bashing of IPCC and scientists who
>>contributed to IPCC (which, I understand, has been particularly viscious
>>and ad hominem inside closed rooms in Washington DC where their words
>>don't make it into the public record). This might all seem laughable, it
>>weren't the case that they've gotten the (Bush) White House Office of
>>Science & Technology taking it as a serious matter (fortunately, Dave
>>Halpern is in charge of this project, and he is likely to handle this
>>appropriately, but without some external pressure).
>>
>>So while our careful efforts to debunk the myths perpetuated by these
>>folks may be useful in the FAR, they will be of limited use in fighting
>>the disinformation campaign that is already underway in Washington DC.
>>Here, I tend to concur at least in sprit w/ Jim Salinger, that other
>>approaches may be necessary. I would emphasize that there are indeed, as
>>Tom notes, some unique aspects of this latest assault by the skeptics
>>which are cause for special concern. This latest assault uses a
>>compromised peer-review process as a vehicle for launching a scientific
>>disinformation campaign (often viscious and ad hominem) under the guise
>>of apparently legitimately reviewed science, allowing them to make use of
>>the "Harvard" moniker in the process. Fortunately, the mainstream media
>>never touched the story (mostly it has appeared in papers owned by
>>Murdoch and his crowd, and dubious fringe on-line outlets). Much like a
>>server which has been compromised as a launching point for computer
>>viruses, I fear that "Climate Research" has become a hopelessly
>>compromised vehicle in the skeptics' (can we find a better word?)
>>disinformation campaign, and some of the discussion that I've seen (e.g.
>>a potential threat of mass resignation among the legitimate members of
>>the CR editorial board) seems, in my opinion, to have some potential merit.
>>
>>This should be justified not on the basis of the publication of science
>>we may not like of course, but based on the evidence (e.g. as provided by
>>Tom and Danny Harvey and I'm sure there is much more) that a legitimate
>>peer-review process has not been followed by at least one particular
>>editor. Incidentally, the problems alluded to at GRL are of a different
>>nature--there are simply too many papers, and too few editors w/
>>appropriate disciplinary expertise, to get many of the papers submitted
>>there properly reviewed. Its simply hit or miss with respect to whom the
>>chosen editor is. While it was easy to make sure that the worst papers,
>>perhaps including certain ones Tom refers to, didn't see the light of the
>>day at /J. Climate/, it was inevitable that such papers might slip
>>through the cracks at e.g. GRL--there is probably little that can be done
>>here, other than making sure that some qualified and responsible climate
>>scientists step up to the plate and take on editorial positions at GRL.
>>
>>best regards,
>>
>>Mike
>>
>>At 11:53 PM 4/23/2xxx xxxx xxxx, Tom Wigley wrote:
>>
>>>Dear friends,
>>>
>>>[Apologies to those I have missed who have been part of this email
>>>exchange -- although they may be glad to have been missed]
>>>
>>>I think Barrie Pittock has the right idea -- although there are some
>>>unique things about this situation. Barrie says ....
>>>
>>>(1) There are lots of bad papers out there
>>>(2) The best response is probably to write a 'rebuttal'
>>>
>>>to which I add ....
>>>
>>>(3) A published rebuttal will help IPCC authors in the 4AR.
>>>
>>>____________________
>>>
>>>Let me give you an example. There was a paper a few years ago by Legates
>>>and Davis in GRL (vol. 24, pp. 2xxx xxxx xxxx, 1997) that was nothing more
>>>than a direct
>>>and pointed criticism of some work by Santer and me -- yet neither of us
>>>was asked to review the paper. We complained, and GRL admitted it was
>>>poor judgment on the part of the editor. Eventually (> 2 years later)
>>>we wrote a response (GRL 27, 2xxx xxxx xxxx, 2000). However, our response was
>>>more that just a rebuttal, it was an attempt to clarify some issues on
>>>detection. In doing things this way we tried to make it clear that the
>>>original Legates/Davis paper was an example of bad science (more
>>>bluntly, either sophomoric ignorance or deliberate misrepresentation).
>>>
>>>Any rebuttal must point out very clearly the flaws in the original
>>>paper. If some new science (or explanations) can be added -- as we did
>>>in the above example -- then this is an advantage.
>>>
>>>_____________________________
>>>
>>>There is some personal judgment involved in deciding whether to rebut.
>>>Correcting bad science is the first concern. Responding to unfair
>>>personal criticisms is next. Third is the possible misrepresentation of
>>>the results by persons with ideological or political agendas. On the
>>>basis of these I think the Baliunas paper should be rebutted by persons
>>>with appropriate expertise. Names like Mann, Crowley, Briffa, Bradley,
>>>Jones, Hughes come to mind. Are these people willing to spend time on
>>>this?
>>>
>>>_______________________________
>>>
>>>There are two other examples that I know of where I will probably be
>>>involved in writing a response.
>>>
>>>The first is a paper by Douglass and Clader in GRL (vol. 29, no. 16,
>>>10.1029/2002GL015345, 2002). I refereed a virtually identical paper for
>>>J. Climate, recommending rejection. All the other referees recommended
>>>rejection too. The paper is truly appalling -- but somehow it must have
>>>been poorly reviewed by GRL and slipped through the net. I have no
>>>reason to believe that this was anything more than chance. Nevertheless,
>>>my judgment is that the science is so bad that a response is necessary.
>>>
>>>The second is the paper by Michaels et al. that was in Climate Research
>>>(vol. 23, pp. 19, 2002). Danny Harvey and I refereed this and said it
>>>should be rejected. We questioned the editor (deFreitas again!) and he
>>>responded saying .....
>>>
>>>The MS was reviewed initially by five referees. ... The other three
>>>referees, all reputable atmospheric scientists, agreed it should be
>>>published subject to minor revision. Even then I used a sixth person
>>>to help me decide. I took his advice and that of the three other
>>>referees and sent the MS back for revision. It was later accepted for
>>>publication. The refereeing process was more rigorous than usual.
>>>
>>>On the surface this looks to be above board -- although, as referees who
>>>advised rejection it is clear that Danny and I should have been kept in
>>>the loop and seen how our criticisms were responded to.
>>>
>>>It is possible that Danny and I might write a response to this paper --
>>>deFreitas has offered us this possibility.
>>>
>>>______________________________
>>>
>>>This second case gets to the crux of the matter. I suspect that
>>>deFreitas deliberately chose other referees who are members of the
>>>skeptics camp. I also suspect that he has done this on other occasions.
>>>How to deal with this is unclear, since there are a number of
>>>individuals with bona fide scientific credentials who could be used by
>>>an unscrupulous editor to ensure that 'anti-greenhouse' science can get
>>>through the peer review process (Legates, Balling, Lindzen, Baliunas,
>>>Soon, and so on).
>>>
>>>The peer review process is being abused, but proving this would be
>>>difficult.
>>>
>>>The best response is, I strongly believe, to rebut the bad science that
>>>does get through.
>>>
>>>_______________________________
>>>
>>>Jim Salinger raises the more personal issue of deFreitas. He is clearly
>>>giving good science a bad name, but I do not think a barrage of ad
>>>hominem attacks or letters is the best way to counter this.
>>>
>>>If Jim wishes to write a letter with multiple authors, I may be willing
>>>to sign it, but I would not write such a letter myself.
>>>
>>>In this case, deFreitas is such a poor scientist that he may simply
>>>disappear. I saw some work from his PhD, and it was awful (Pat Michaels'
>>>PhD is at the same level).
>>>
>>>______________________________
>>>
>>>Best wishes to all,
>>>Tom.
>>
>>______________________________________________________________
>> Professor Michael E. Mann
>> Department of Environmental Sciences, Clark Hall
>> University of Virginia
>> Charlottesville, VA 22903
>>_______________________________________________________________________
>>e-mail: mann@xxxxxxxxx.xxx Phone: (4xxx xxxx xxxxFAX: (4xxx xxxx xxxx
>> http://www.evsc.virginia.edu/faculty/people/mann.shtml
>
>
>--
>C. Mark Eakin, Ph.D.
>Chief of NOAA Paleoclimatology Program and
>Director of the World Data Center for Paleoclimatology
>
>NOAA/National Climatic Data Center
>325 Broadway E/CC23
>Boulder, CO 80xxx xxxx xxxx
>Voice: xxx xxxx xxxx Fax: xxx xxxx xxxx
>Internet: mark.eakin@xxxxxxxxx.xxx
>http://www.ngdc.noaa.gov/paleo/paleo.html
>
>
_______________________________________________________________________
Professor Michael E. Mann
Department of Environmental Sciences, Clark Hall
University of Virginia
Charlottesville, VA 22903
_______________________________________________________________________
e-mail: mann@xxxxxxxxx.xxx Phone: (4xxx xxxx xxxxFAX: (4xxx xxxx xxxx
http://www.evsc.virginia.edu/faculty/people/mann.shtml
</x-flowed>
Original Filename: 1051230500.txt | Return to the index page | Permalink | Later Emails
From: j.salinger@xxxxxxxxx.xxx
To: Tom Wigley <wigley@xxxxxxxxx.xxx>, Phil Jones <p.jones@xxxxxxxxx.xxx>, Mike Hulme <m.hulme@xxxxxxxxx.xxx>, Keith Briffa <k.briffa@xxxxxxxxx.xxx>, James Hansen <jhansen@xxxxxxxxx.xxx>, Danny Harvey <harvey@xxxxxxxxx.xxx>, Ben Santer <santer1@xxxxxxxxx.xxx>, Kevin Trenberth <trenbert@xxxxxxxxx.xxx>, Robert wilby <rob.wilby@xxxxxxxxx.xxx>, "Michael E. Mann" <mann@xxxxxxxxx.xxx>, Tom Karl <Thomas.R.Karl@xxxxxxxxx.xxx>, Steve Schneider <shs@xxxxxxxxx.xxx>, Tom Crowley <tcrowley@xxxxxxxxx.xxx>, jto <jto@u.arizona.edu>, "simon.shackley" <simon.shackley@xxxxxxxxx.xxx>, "tim.carter" <tim.carter@xxxxxxxxx.xxx>, "p.martens" <p.martens@xxxxxxxxx.xxx>, "peter.whetton" <peter.whetton@xxxxxxxxx.xxx>, "c.goodess" <c.goodess@xxxxxxxxx.xxx>, "a.minns" <a.minns@xxxxxxxxx.xxx>, Wolfgang Cramer <Wolfgang.Cramer@xxxxxxxxx.xxx>, "j.salinger" <j.salinger@xxxxxxxxx.xxx>, "simon.torok" <simon.torok@xxxxxxxxx.xxx>, Mark Eakin <mark.eakin@xxxxxxxxx.xxx>, Scott Rutherford <srutherford@xxxxxxxxx.xxx>, Neville Nicholls <n.nicholls@xxxxxxxxx.xxx>, Ray Bradley <rbradley@xxxxxxxxx.xxx>, Mike MacCracken <mmaccrac@xxxxxxxxx.xxx>, Barrie Pittock <Barrie.Pittock@xxxxxxxxx.xxx>, Ellen Mosley-Thompson <thompson4@xxxxxxxxx.xxx>, "pachauri@xxxxxxxxx.xxx" <pachauri@xxxxxxxxx.xxx>, "Greg.Ayers" <Greg.Ayers@xxxxxxxxx.xxx>, Tom Wigley <wigley@xxxxxxxxx.xxx>
Subject: And again from the south!
Date: Thu, 24 Apr 2003 20:28:20 +1200
Dear friends and colleagues
This will be the last from me for the moment and I believe we are all
arriving at a consensus voiced by Tom, Barrie, Neville et al., from
excellent discussions.
Firstly both Danny and Tom have complained to de Freitas about
his editorial decision, which does not uphold the principles of good
science. Tom has shared the response. I would be curious to find
out who the other four cited are - but a rebuttal would be excellent.
Ignoring bad science eventually reinforces the apparent 'truth' of
that bad science in the public mind, if it is not corrected. As
importantly, the 'bad science' published by CR is used by the
sceptics' lobbies to 'prove' that there is no need for concern over
climate change. Since the IPCC makes it quite clear that there are
substantial grounds for concern about climate change, is it not
partially the responsibility of climate science to make sure only
satisfactorily peer-reviewed science appears in scientific
publications? - and to refute any inadequately reviewed and wrong
articles that do make their way through the peer review process?
I can understand the weariness which the ongoing sceptics'
onslaught would induce in anyone, scientist or not. But that's no
excuse for ignoring bad science. It won't go away, and the more
we ignore it the more traction it will gain in the minds of the general
public, and the UNFCCC negotiators. If science doesn't uphold the
purity of science, who will?
We Australasians (including Tom as an ex pat) have suggested
some courses of action. Over to you now in the north to assess
the success of your initiatives, the various discussions and
suggestions and arrive on a path ahead. I am happy to be part of it.
Warm wishes to all
Jim
On 23 Apr 2003, at 23:53, Tom Wigley wrote:
> Dear friends,
>
> [Apologies to those I have missed who have been part of this email
> exchange -- although they may be glad to have been missed]
>
> I think Barrie Pittock has the right idea -- although there are some
> unique things about this situation. Barrie says ....
>
> (1) There are lots of bad papers out there
> (2) The best response is probably to write a 'rebuttal'
>
> to which I add ....
>
> (3) A published rebuttal will help IPCC authors in the 4AR.
>
> ____________________
>
> Let me give you an example. There was a paper a few years ago by
> Legates and Davis in GRL (vol. 24, pp. 2xxx xxxx xxxx, 1997) that was
> nothing more than a direct and pointed criticism of some work by
> Santer and me -- yet neither of us was asked to review the paper. We
> complained, and GRL admitted it was poor judgment on the part of the
> editor. Eventually (> 2 years later) we wrote a response (GRL 27,
> 2xxx xxxx xxxx, 2000). However, our response was more that just a rebuttal,
> it was an attempt to clarify some issues on detection. In doing things
> this way we tried to make it clear that the original Legates/Davis
> paper was an example of bad science (more bluntly, either sophomoric
> ignorance or deliberate misrepresentation).
>
> Any rebuttal must point out very clearly the flaws in the original
> paper. If some new science (or explanations) can be added -- as we did
> in the above example -- then this is an advantage.
>
> _____________________________
>
> There is some personal judgment involved in deciding whether to rebut.
> Correcting bad science is the first concern. Responding to unfair
> personal criticisms is next. Third is the possible misrepresentation
> of the results by persons with ideological or political agendas. On
> the basis of these I think the Baliunas paper should be rebutted by
> persons with appropriate expertise. Names like Mann, Crowley, Briffa,
> Bradley, Jones, Hughes come to mind. Are these people willing to spend
> time on this?
>
> _______________________________
>
> There are two other examples that I know of where I will probably be
> involved in writing a response.
>
> The first is a paper by Douglass and Clader in GRL (vol. 29, no. 16,
> 10.1029/2002GL015345, 2002). I refereed a virtually identical paper
> for J. Climate, recommending rejection. All the other referees
> recommended rejection too. The paper is truly appalling -- but somehow
> it must have been poorly reviewed by GRL and slipped through the net.
> I have no reason to believe that this was anything more than chance.
> Nevertheless, my judgment is that the science is so bad that a
> response is necessary.
>
> The second is the paper by Michaels et al. that was in Climate
> Research (vol. 23, pp. 1
Original Filename: 1057941657.txt | Return to the index page | Permalink | Later Emails
From: Ben Santer <santer1@xxxxxxxxx.xxx>
To: Phil Jones <p.jones@xxxxxxxxx.xxx>, rls@xxxxxxxxx.xxx
Subject: More on Climate Research.....
Date: Fri, 11 Jul 2003 12:40:xxx xxxx xxxx
Cc: Tom Wigley <wigley@xxxxxxxxx.xxx>, "Michael E. Mann" <mann@xxxxxxxxx.xxx>, Mike Hulme <m.hulme@xxxxxxxxx.xxx>
Dear Phil,
In June 2003, Climate Research published a paper by David Douglass et al. The
"et al." includes John Christy and Pat Michaels. Douglass et al. attempt to
debunk the paper that Tom and I published in JGR in 2001 ("Accounting for the
effects of volcanoes and ENSO in comparisons of modeled and observed temperature
trends"; JGR 106, 28xxx xxxx xxxx). The Douglass et al. paper claims (and purports
to show) that collinearity between ENSO, volcanic, and solar predictor variables
is not a serious problem in studies attempting to estimate the effects of these
factors on MSU tropospheric temperatures. Their work has serious scientific
flaws - it confuses forcing and response, and ignores strong temporal
autcorrelation in the individual predictor variables, incorrectly assuming
independence of individual monthly means in the MSU 2LT data. In the Douglass et
al. view of the world, uncertainties in predictor variables, observations, etc.
are non-existent. The error bars on their estimated ENSO, volcano, and solar
regression coefficients are miniscule.
Over a year ago, Tom and I reviewed (for JGR) a paper by Douglass et al. that
was virtually identical to the version that has now appeared in Climate
Research. We rejected it. Prior to this, both Tom and I had engaged in a long
and frustrating dialogue with Douglass, in which we attempted to explain to him
that there are large uncertainties in the deconvolution of ENSO, volcano, and
solar signals in short MSU records. Douglass chose to ignore all of the comments
we made in this exchange, as he later ignored all of the comments we made in our
reviews of his rejected JGR paper.
Although the Douglass et al. Climate Research paper is largely a criticism of
our previously-published JGR paper, neither Tom nor I were asked to review the
paper for Climate Research. Nor were any other coauthors of the Santer et al.
JGR paper asked to review the Douglass et al. manuscript. I'm assuming that
Douglass specifically requested that neither Tom nor I should be allowed to act
as reviwers of his Climate Research paper. It would be interesting to see his
cover letter to the journal.
In the editorial that you forwarded, Dr. Kinne writes the following:
"If someone wishes to criticise a published paper s/he must present facts and
arguments and give criticised parties a chance to defend their position." The
irony here is that in our own experience, the "criticised parties" (i.e., Tom
and I) were NOT allowed to defend their positions.
Based on Kinne's editorial, I see little hope for more enlightened editorial
decision making at Climate Research. Tom, Richard Smith and I will eventually
publish a rebuttal to the Douglass et al. paper. We'll publish this rebuttal in
JGR - not in Climate Research.
With best regards,
Ben
======================================================================================
Phil Jones wrote:
>
> Dear All,
> Finally back in the UK after Asheville and IUGG. Attached is an
> editorial from the
> latest issue of climate research. I can only seem to save it this way.
> Seems like we are
> now the bad guys.
>
> Cheers
> Phil
>
> At 07:51 04/07/xxx xxxx xxxx, Tom Wigley wrote:
> >Mike (Mann),
> >I agree that Kinne seems like he could be a deFreitas clone. However, what
> >would be our legal position if we were to openly and extensively tell
> >people to avoid the journal?
> >Tom.
> >__________________________________
> >
> >Michael E. Mann wrote:
> >>Thanks Mike
> >>It seems to me that this "Kinne" character's words are disingenuous, and
> >>he probably supports what De Freitas is trying to do. It seems clear we
> >>have to go above him.
> >>I think that the community should, as Mike H has previously suggested in
> >>this eventuality, terminate its involvement with this journal at all
> >>levels--reviewing, editing, and submitting, and leave it to wither way
> >>into oblivion and disrepute,
> >>Thanks,
> >>mike
> >>At 01:00 PM 7/3/2003 +0100, Mike Hulme wrote:
> >>
> >>>Phil, Tom, Mike,
> >>>
> >>>So, this would seem to be the end of the matter as far as Climate
> >>>Research is concerned.
> >>>
> >>>Mike
> >>>
> >>>>To
> >>>>CLIMATE RESEARCH
> >>>>Editors and Review Editors
> >>>>
> >>>>Dear colleagues,
> >>>>
> >>>>In my 20.06. email to you I stated, among other things, that I would
> >>>>ask CR editor Chris de Freitas to present to me copies of the
> >>>>reviewers' evaluations for the 2 Soon et al. papers.
> >>>>
> >>>>I have received and studied the material requested.
> >>>>
> >>>>Conclusions:
> >>>>
> >>>>1) The reviewers consulted (4 for each ms) by the editor presented
> >>>>detailed, critical and helpful evaluations
> >>>>
> >>>>2) The editor properly analyzed the evaluations and requested
> >>>>appropriate revisions.
> >>>>
> >>>>3) The authors revised their manuscripts accordingly.
> >>>>
> >>>>Summary:
> >>>>
> >>>>Chris de Freitas has done a good and correct job as editor.
> >>>>
> >>>>Best wishes,
> >>>>Otto Kinne
> >>>>Director, Inter-Research
> >>>>--
> >>>>-------------------------------------------------
> >>>>Inter-Research, Science Publisher
> >>>>Ecology Institute
> >>>>Nordbuente 23,
> >>>>D-21385 Oldendorf/Luhe,
> >>>>Germany
> >>>>Tel: (+49) (41xxx xxxx xxxxEmail: ir@xxxxxxxxx.xxx
> >>>>Fax: (+49) (41xxx xxxx xxxxhttp://www.int-res.com <http://www.int-res.com/>
> >>>>
> >>>>
> >>>>Inter-Research - Publisher of Scientific Journals and Book Series:
> >>>>
> >>>>- Marine Ecology Progress Series (MEPS)
> >>>>- Aquatic Microbial Ecology (AME)
> >>>>- Diseases of Aquatic Organisms (DA0)
> >>>>- Climate Research (CR)
> >>>>- Ethics in Science and Environmental Politics (ESEP)
> >>>>- Excellence in Ecology
> >>>>- Top Books
> >>>>- EEIU Brochures
> >>>>
> >>>>YOU ARE INVITED TO VISIT OUR WEB SITES: www.int-res.com
> >>>><http://www.int-res.com /> and www.eeiu.org <http://www.eeiu.org/>
> >>>>
> >>>>-------------------------------------------------
> >>>
> >>______________________________________________________________
> >> Professor Michael E. Mann
> >> Department of Environmental Sciences, Clark Hall
> >> University of Virginia
> >> Charlottesville, VA 22903
> >>_______________________________________________________________________
> >>e-mail: mann@xxxxxxxxx.xxx Phone: (4xxx xxxx xxxxFAX: (4xxx xxxx xxxx
> >> http://www.evsc.virginia.edu/faculty/people/mann.shtml
> >
>
> Prof. Phil Jones
> Climatic Research Unit Telephone +44 xxx xxxx xxxx
> School of Environmental Sciences Fax +44 xxx xxxx xxxx
> University of East Anglia
> Norwich Email p.jones@xxxxxxxxx.xxx
> NR4 7TJ
> UK
> ----------------------------------------------------------------------------
>
> --------------------------------------------------------------------------------
> Name: CR.txt
> CR.txt Type: Plain Text (text/plain)
> Encoding: quoted-printable
--
----------------------------------------------------------------------------
PCMDI HAS MOVED TO A NEW BUILDING. NOTE CHANGE OF MAIL CODE!
Benjamin D. Santer
Program for Climate Model Diagnosis and Intercomparison
Lawrence Livermore National Laboratory
P.O. Box 808, Mail Stop L-103
Livermore, CA 94550, U.S.A.
Tel: (9xxx xxxx xxxx
FAX: (9xxx xxxx xxxx
email: santer1@xxxxxxxxx.xxx
----------------------------------------------------------------------------
Original Filename: 1069630979.txt | Return to the index page | Permalink | Later Emails
From: RichardSCourtney@xxxxxxxxx.xxx
To: t.osborn@xxxxxxxxx.xxx, m.allen1@xxxxxxxxx.xxx, Russell.Vose@xxxxxxxxx.xxx
Subject: Re: Workshop: Reconciling Vertical Temperature Trends
Date: Sun, 23 Nov 2003 18:42:59 EST
Cc: trenbert@xxxxxxxxx.xxx, timo.hameranta@xxxxxxxxx.xxx, Thomas.R.Karl@xxxxxxxxx.xxx, ceforest@xxxxxxxxx.xxx, sokolov@xxxxxxxxx.xxx, phstone@xxxxxxxxx.xxx, ekalnay@xxxxxxxxx.xxx, richard.w.reynolds@xxxxxxxxx.xxx, christy@xxxxxxxxx.xxx, roy.spencer@xxxxxxxxx.xxx, benjie.norris@xxxxxxxxx.xxx, kostya@xxxxxxxxx.xxx, Norman.Grody@xxxxxxxxx.xxx, Thomas.C.Peterson@xxxxxxxxx.xxx, sfbtett@xxxxxxxxx.xxx, penner@xxxxxxxxx.xxx, dian.seidel@xxxxxxxxx.xxx, trenbert@xxxxxxxxx.xxx, wigley@xxxxxxxxx.xxx, pielke@xxxxxxxxx.xxx, climatesceptics@xxxxxxxxx.xxx, aarking1@xxxxxxxxx.xxx, bjorn@xxxxxxxxx.xxx, cfk@xxxxxxxxx.xxx, c.defreitas@xxxxxxxxx.xxx, cidso@xxxxxxxxx.xxx, dwojick@xxxxxxxxx.xxx, douglass@xxxxxxxxx.xxx, dkaroly@xxxxxxxxx.xxx, mercurio@xxxxxxxxx.xxx, fredev@xxxxxxxxx.xxx, seitz@xxxxxxxxx.xxx, Heinz.Hug@xxxxxxxxx.xxx, hughel@xxxxxxxxx.xxx, jahlbeck@xxxxxxxxx.xxx, jfriday@xxxxxxxxx.xxx, jeb@xxxxxxxxx.xxx, daly@xxxxxxxxx.xxx, kondratyev@xxxxxxxxx.xxx, klyashtorin@xxxxxxxxx.xxx, SCRIPTEC@xxxxxxxxx.xxx, marsleroux@xxxxxxxxx.xxx, visbeck@xxxxxxxxx.xxx, mmaccrac@xxxxxxxxx.xxx, schlesin@xxxxxxxxx.xxx, n.polunin@xxxxxxxxx.xxx, pjm8x@xxxxxxxxx.xxx, per.ericson@xxxxxxxxx.xxx, p_dietze@xxxxxxxxx.xxx, rabryson@xxxxxxxxx.xxx, lindzen@xxxxxxxxx.xxx, singer@xxxxxxxxx.xxx, baliunas@xxxxxxxxx.xxx, wibjorn.karlen@xxxxxxxxx.xxx, wsoon@xxxxxxxxx.xxx, vinmary.gray@xxxxxxxxx.xxx, berger@xxxxxxxxx.xxx, andre@xxxxxxxxx.xxx, avogelmann@xxxxxxxxx.xxx, tonyb@xxxxxxxxx.xxx, ottobli@xxxxxxxxx.xxx, cwunsch@xxxxxxxxx.xxx, schoenwiese@xxxxxxxxx.xxx, ds533@xxxxxxxxx.xxx, david.easterling@xxxxxxxxx.xxx, legates@xxxxxxxxx.xxx, wuebbles@xxxxxxxxx.xxx, thompson.4@xxxxxxxxx.xxx, joos@xxxxxxxxx.xxx, kukla@xxxxxxxxx.xxx, gcb@xxxxxxxxx.xxx, Hans.von.Storch@xxxxxxxxx.xxx, igor@xxxxxxxxx.xxx, jhansen@xxxxxxxxx.xxx, jfbmitchell@xxxxxxxxx.xxx, josefino.c.comiso@xxxxxxxxx.xxx, jlean@xxxxxxxxx.xxx, k.briffa@xxxxxxxxx.xxx, kenc@xxxxxxxxx.xxx, klaus-p-heiss@xxxxxxxxx.xxx, kump@xxxxxxxxx.xxx, thompson.3@xxxxxxxxx.xxx, jacobson@xxxxxxxxx.xxx, claussen@xxxxxxxxx.xxx, m.manning@xxxxxxxxx.xxx, marty.hoffert@xxxxxxxxx.xxx, mike.bergin@xxxxxxxxx.xxx, mauel@xxxxxxxxx.xxx, glantz@xxxxxxxxx.xxx, omichael@xxxxxxxxx.xxx, rodolfo@xxxxxxxxx.xxx, olavi@xxxxxxxxx.xxx, ocanz@xxxxxxxxx.xxx, air@xxxxxxxxx.xxx, pdoran@xxxxxxxxx.xxx, p.jones@xxxxxxxxx.xxx, tpatters@xxxxxxxxx.xxx, rmyneni@xxxxxxxxx.xxx, rasmus.benestad@xxxxxxxxx.xxx, rbradley@xxxxxxxxx.xxx, anthes@xxxxxxxxx.xxx, robert.sausen@xxxxxxxxx.xxx, shs@xxxxxxxxx.xxx, wofsy@xxxxxxxxx.xxx, smenon@xxxxxxxxx.xxx, ssolomon@xxxxxxxxx.xxx, tbarnett@xxxxxxxxx.xxx, ulrich.berner@xxxxxxxxx.xxx, cubasch@xxxxxxxxx.xxx, Uli.Neff@xxxxxxxxx.xxx, vramanathan@xxxxxxxxx.xxx, vr@xxxxxxxxx.xxx, broecker@xxxxxxxxx.xxx
Dear All:
The excuses seem to be becoming desperate. Unjustified assertion that I fail to understand
"Myles' comments and/or work on trying the detect/attribute climate change" does not stop
the attribution study being an error. The problem is that I do understand what is being
done, and I am willing to say why it is GIGO.
Tim Allen said;
In a message dated 19/11/03 08:47:16 GMT Standard Time, m.allen1@xxxxxxxxx.xxx writes:
I would just like
to add that those of us working on climate change detection and attribution
are careful to mask model simulations in the same way that the observations
have been sampled, so these well-known dependencies of nominal trends on the
trend-estimation technique have no bearing on formal detection and
attribution results as quoted, for example, in the IPCC TAR.
I rejected this saying:
At 09:31 21/11/2003, RichardSCourtney@xxxxxxxxx.xxx wrote:
>It cannot be known that the 'masking' does not generate additional
>spurious trends. Anyway, why assume the errors in the data sets are
>geographical and not?. The masking is a 'fix' applied to the model
>simulations to adjust them to fit the surface data known to contain
>spurious trends. This is simple GIGO.
Now, Tim Osborn says of my comment;
In a message dated 21/11/03 10:04:56 GMT Standard Time, t.osborn@xxxxxxxxx.xxx writes:
Richard's statement makes it clear, to me at least, that he misunderstands
Myles' comments and/or work on trying the detect/attribute climate change.
As far as I understand it, the masking is applied to the model to remove
those locations/times when there are no observations. This is quite
different to removing those locations which do not match, in some way, with
the observations - that would clearly be the wrong thing to do. To mask
those that have no observations, however, is clearly the right thing to do
- what is the point of attempting to detect a simulated signal of climate
change over some part of (e.g.) the Southern Ocean if there are no
observations there in which to detect the expected signal? That would
clearly be pointless.
Yes it would. And I fully understand Myles' comments. Indeed, my comments clearly and
unarguably relate to Myles comments. But, as my response states, Myles' comments do not
alter the fact that the masked data and the unmasked data contain demonstrated false
trends. And the masking may introduce other spurious trends. So, the conducted
attribution study is pointless because it is GIGO. Ad hominem insults don't change that.
And nor does the use of peer review to block my publication of the facts of these matters.
Richard
Original Filename: 1093794363.txt | Return to the index page | Permalink | Later Emails
From: Martin Munro <mmunro@xxxxxxxxx.xxx>
To: ITRDBFOR@xxxxxxxxx.xxx
Subject: Calibration loose ends (was Re: [ITRDBFOR] crossdating)
Date: Sun, 29 Aug 2004 11:46:xxx xxxx xxxx
Reply-to: grissino@xxxxxxxxx.xxx
This an attempt to tie up the loose ends from an earlier part of the
discussion, the idea that calibration of the radiocarbon timescale be
considered invalid, pending a better understanding of crossdating.
Some of the previous posts seem to imply that measurements of the C-14
half-life depend on the calibration; in fact it can be determined by
present-day laboratory measurements without reference to any old
material, simply by observing the decay rate in a known quantity of
the isotope. Physicists seem happy that beta decay isn't affected by
mundane external influences, so the half life should be constant. If
the amount of C-14 in a sample depends only on its age and the
(constant) half life, a calibration curve from a collection of samples
of known true age would be a diagonal straight line; but this would
imply that each sample started with the same concentration of C-14.
There are many effects that could change this concentration through
time: variations in cosmic ray sources, changing solar activity,
changes in the upper atmosphere, atmospheric circulation, uptake and
release of carbon from large sinks and sources... etc. Given enough
correctly dated samples, you can recover the sum of these variations
from the form of the calibration curve. In practice, the most
important variation appear to be on multi-millennial scales, with
smaller fluctuations (wiggles) on century/multi-decadal scales
superimposed on this.
Wood from crossdated tree rings provided the known-age reference
material used in the calibration curves, and there were two main
phases of work, the first of which roughed out the general form of the
curve and hinted at the short-period structure, the second of which
reconstructed the century-scale variations in detail using higher
precision measurements. Contamination of old samples with C-14 of
more recent origin is a widely recognized problem, addressed by
physical and chemical pre-treatment protocols for the material. A
couple of complicating effects that are of more interest from a tree-
physiological point of view. Isotopic fractionation occurs along the
entire chain of processes between carbon in the environment and its
incorporation in the specific components of the wood that end up in
the calibration samples. A ring forming in a particular year might
continue to accumulate C-14 in subsequent years. But people who work
with C-14 are well aware of various corrections for isotopic
fractionation, and the migration of carbon across ring boundaries has
been the subject of several empirical investigations, notably using
the stepwise change in C-14 concentrations following atmospheric
nuclear tests in the 1950s and 60s as a tracer. The more recent phase
of calibration work was substantially complete around 15 years ago,
and was covered in an extensive series of journal articles and
symposia.
Let's suppose we have been provided with a demonstration that
crossdating is invalid: what would be the consequences for C-14
calibration? One of the most alarming would be that we would have to
come up with a convincing explanation of how independent tree ring
chronologies could be in error in precisely the same way---the
known-age reference samples are not just from bristlecone pines, and
crossdating within the network of oak chronologies is completely
independent of the bristlecones. Both are completely self-supporting
chains of inferences anchored in living trees and extending back into
sub-fossil wood. There are published comparisons of paired
calibration curves, with the absolute dates and C-14 concentrations
based on oaks in one case, and on bristlecones in the other. My
understanding of tree physiology is rudimentary at best, but surely
when two such vastly different wood anatomies are involved there must
be differences in the physiological constraints on wood formation. If
potentially unidentified missing rings are supposed to be the most
serious problem with the bristlecone chronologies, the oak
chronologies should not be affected in any case, since they almost
never include missing rings in this sense (although that's not to say
they have no anatomical ambiguities that can confound crossdating).
The crossdating error could not be merely a shared systematic bias;
not only does the long term trend in the calibration curves derived
from the two chronologies share a common non-linear trend, but the
short-term fluctuations in C-14 concentration (wiggles) match between
the two curves. There are small differences between calibrations
derived from different geographical regions, but these have themselves
formed the basis for further research and geophysical modeling.
The strengths of the two sets of chronologies are complimentary. Oaks
may have almost no missing rings (sensu stricto) and provide larger
volumes of wood for C-14 analysis, but the individual samples are only
a few hundred years long, showing significant variations in growth
with increasing pith age, and (particularly in the case of the
sub-fossil wood) there will be uncertainties about the environment in
which the tree was growing. Bristlecone pines give a much better
chance of finding wood that has grown over periods of many centuries
with no marked age-related trends, and there's a compelling continuity
between the living trees and the remnant wood lying on the ground
nearby.
An account of wood formation from a physiological perspective would
undoubtedly be a beautiful thing in its own right, even if it had
little to contribute to dendrochronology. Moreover one of my pet
peeves is seeing people manipulate data as mere collections of numbers
divorced from any underlying model---and in the case of
dendrochronolgy the model has to be biological. But I'd number myself
amongst those who can't see why our use of crossdating must await a
reasonably complete physiological model of wood formation. By
analogy, if the doctors in some traditional society are using a human
physiology based on the balance or imbalance of the four humours, but
they have a treatment for a particular disease that results in an 80%
survival rate, as opposed to a %40 survival rate if it goes untreated,
you're obviously better off slurping down their bitter potion first
and working out the explanation in current Western physiological terms
afterwards (if that's the only treatment option).
So even if at present our understanding of crossdating is largely
limited to statistical phenomenology, that may be good enough to live
with until something better comes along. That's not to imply that we
should be credulous, and automatically accept current practices simply
because great authorities have taken the same route: astronomers were
at one time expected to work as astrological consultants, casting
horoscopes for rulers and interpreting signs in the sky in terms of
current political affairs. There's no necessary reason to follow
Douglass' crossdating methods any more than we should follow Kepler's
example of casting horoscopes---unless they work. Although the seeming
effectiveness of crossdating could in principle be invalid, it
has been applied so widely that we would need presented with a very
strong critique before abandoning it.
I'm not really qualified to discuss crossdating and C-14 calibration
from a point of view of someone active in current research, but was
fortunate to be sitting on the sidelines of the oak calibration work
in the 80s, and just the other day Tom Harlan dropped by with the
oldest known absolutely dated bristlecone sample, so will offer
this as a kind of correction by proxy until any of the people
who've done the real work care to comment
---Martin.
Original Filename: 1106322460.txt | Return to the index page | Permalink | Later Emails
From: Malcolm Hughes <mhughes@xxxxxxxxx.xxx>
To: "Michael E. Mann" <mann@xxxxxxxxx.xxx>
Subject: Re: Fwd: Your concerns with 2004GL021750 McIntyre
Date: Fri, 21 Jan 2005 10:47:xxx xxxx xxxx
Cc: Tom Wigley <wigley@xxxxxxxxx.xxx>, rbradley@xxxxxxxxx.xxx, t.osborn@xxxxxxxxx.xxx, wigley@xxxxxxxxx.xxx, phil Jones <p.jones@xxxxxxxxx.xxx>, keith Briffa <k.briffa@xxxxxxxxx.xxx>, Gavin Schmidt <gschmidt@xxxxxxxxx.xxx>
<x-flowed>
Michael E. Mann wrote:
> Hi Malcolm,
>
> This assumes that the editor/s in question would act in good faith.
> I'm not convinced of this.
>
> I don't believe a response in GRL is warranted in any case. The MM
> claims in question are debunked in other papers that are in press and
> in review elsewhere. I'm not sure that GRL can be seen as an honest
> broker in these debates anymore, and it is probably best to do an end
> run around GRL now where possible. They have published far too many
> deeply flawed contrarian papers in the past year or so. There is no
> possible excuse for them publishing all 3 Douglass papers and the Soon
> et al paper. These were all pure crap.
>
> There appears to be a more fundamental problem w/ GRL now,
> unfortunately...
>
> Mike
>
> At 08:47 PM 1/20/2005, mhughes@xxxxxxxxx.xxx wrote:
>
>> Mike - I found this sentence in the reply from the GRL
>> Editor-in-Chief to be
>> interesting:
>> "As this manuscript was not written as a Comment, but rather as
>> a full-up scientific manuscript, you would not in general be asked to
>> look it over."
>> Does it not then follow that if you were to challenge their "work" in
>> a "full-
>> up scientific manuscript", but not as a "Comment" it, too, should be
>> reviewed
>> without reference to MM?
>> Maybe the editor-in-chief should be asked if this is the case, or simply
>> challenged by a submission?
>> Cheers, Malcolm
>> Quoting "Michael E. Mann" <mann@xxxxxxxxx.xxx>:
>>
>> >
>> >
>> > Thanks Tom,
>> >
>> >
>> > Yeah, basically this is just a heads up to people that something
>> might be
>> > up here. What a shame that would be. It's one thing to lose "Climate
>> > Research". We can't afford to lose GRL. I think it would be
>> > useful if people begin to record their experiences w/ both Saiers and
>> > potentially Mackwell (I don't know him--he would seem to be
>> complicit w/
>> > what is going on here).
>> >
>> >
>> > If there is a clear body of evidence that something is amiss, it
>> could be
>> > taken through the proper channels. I don't that the entire AGU
>> hierarchy
>> > has yet been compromised!
>> >
>> >
>> > The GRL article simply parrots the rejected Nature comment--little
>> > substantial difference that I can see at all.
>> >
>> >
>> > Will keep you all posted of any relevant developments,
>> >
>> >
>> > mike
>> >
>> >
>> > At 04:30 PM 1/20/2005, Tom Wigley wrote:
>> >
>> > Mike,
>> >
>> >
>> >
>> > This is truly awful. GRL has gone downhill rapidly in recent years.
>> > I
>> >
>> > think the decline began before Saiers. I have had some unhelpful
>> >
>> > dealings with him recently with regard to a paper Sarah and I have
>> >
>> > on glaciers -- it was well received by the referees, and so is in
>> > the
>> >
>> > publication pipeline. However, I got the impression that Saiers was
>> >
>> > trying to keep it from being published.
>> >
>> >
>> > Proving bad behavior here is very difficult. If you think that
>> > Saiers
>> >
>> > is in the greenhouse skeptics camp, then, if we can find
>> > documentary
>> >
>> > evidence of this, we could go through official AGU channels to get
>> >
>> > him ousted. Even this would be difficult.
>> >
>> >
>> > How different is the GRL paper from the Nature paper? Did the
>> >
>> > authors counter any of the criticisms? My experience with Douglass
>> >
>> > is that the identical (bar format changes) paper to one previously
>> >
>> > rejected was submitted to GRL.
>> >
>> >
>> > Tom.
>> >
>> > ===============
>> >
>> >
>> > Michael E. Mann wrote:
>> >
>> > Dear All,
>> >
>> >
>> > Just a heads up. Apparently, the contrarians now have an
>> > "in" with GRL. This guy Saiers has a prior connection w/ the
>> > University of Virginia Dept. of Environmental Sciences that causes me
>> > some unease.
>> >
>> >
>> > I think we now know how the various Douglass et al papers w/
>> Michaels and
>> > Singer, the Soon et al paper, and now this one have gotten published in
>> > GRL,
>> >
>> >
>> > Mike
>> >
>> >
>> >
>> >
>> > Subject: Your concerns with
>> > 2004GL021750 McIntyre
>> >
>> > Date: Thu, 20 Jan 2005 14:42:xxx xxxx xxxx
>> >
>> > X-MS-Has-Attach:
>> >
>> > X-MS-TNEF-Correlator:
>> >
>> > Thread-Topic: Your concerns with 2004GL021750 McIntyre
>> >
>> > Thread-Index: AcT/MITTfwM54m4OS32mJvW4BluE+A==
>> >
>> > From: "Mackwell, Stephen"
>> > <mackwell@xxxxxxxxx.xxx>
>> >
>> > To:
>> > <mann@xxxxxxxxx.xxx>
>> >
>> > Cc: <cjr@xxxxxxxxx.xxx>,
>> > <james.saiers@xxxxxxxxx.xxx>
>> >
>> > X-OriginalArrivalTime: 20 Jan 2005 20:42:12.0740 (UTC)
>> > FILETIME=[84F55440:01C4FF30]
>> >
>> > X-UVA-Virus-Scanned: by amavisd-new at fork7.mail.virginia.edu
>> >
>> > X-MIME-Autoconverted: from base64 to 8bit by
>> multiproxy.evsc.Virginia.EDU
>> > id j0KKgLO11138
>> >
>> >
>> > Dear Prof. Mann
>> >
>> > In your recent email to Chris Reason, you laid out your concerns that I
>> > presume were the reason for your phone call to me last week. I have
>> > reviewed the manuscript by McIntyre, as well as the reviews. The editor
>> > in this case was Prof. James Saiers. He did note initially that the
>> > manuscript did challenge published work, and so felt the need for an
>> > extensive and thorough review. For that reason, he requested
>> reviews from
>> > 3 knowledgable scientists. All three reviews recommended
>> > publication.
>> >
>> > While I do agree that this manuscript does challenge (somewhat
>> > aggresively) some of your past work, I do not feel that it takes a
>> > particularly harsh tone. On the other hand, I can understand your
>> > reaction. As this manuscript was not written as a Comment, but
>> rather as
>> > a full-up scientific manuscript, you would not in general be asked to
>> > look it over. And I am satisfied by the credentials of the reviewers.
>> > Thus, I do not feel that we have sufficient reason to interfere in the
>> > timely publication of this work.
>> >
>> > However, you are perfectly in your rights to write a Comment, in which
>> > you challenge the authors' arguments and assertions. Should you
>> elect to
>> > do this, your Comment would be provided to them and they would be
>> offered
>> > the chance to write a Reply. Both Comment and Reply would then be
>> > reviewed and published together (if they survived the review process).
>> > Comments are limited to the equivalent of 2 journal pages.
>> >
>> > Regards
>> >
>> > Steve Mackwell
>> >
>> > Editor in Chief, GRL
>> >
>> >
>> >
>> > ______________________________________________________________
>> >
>> >
>> > Professor Michael E. Mann
>> >
>> > Department
>> > of Environmental Sciences, Clark Hall
>> >
>> >
>> > University of Virginia
>> >
>> >
>> > Charlottesville, VA 22903
>> >
>> > _______________________________________________________________________
>> >
>> > e-mail:
>> > mann@xxxxxxxxx.xxx
>> > Phone: (4xxx xxxx xxxxFAX: (4xxx xxxx xxxx
>> >
>> >
>> > http://www.evsc.virginia.edu/faculty/people/mann.shtml
>> >
>> > ______________________________________________________________
>> >
>> >
>> > Professor Michael E. Mann
>> >
>> > Department
>> > of Environmental Sciences, Clark Hall
>> >
>> >
>> > University of Virginia
>> >
>> >
>> > Charlottesville, VA 22903
>> >
>> > _______________________________________________________________________
>> >
>> > e-mail: mann@xxxxxxxxx.xxx Phone: (4xxx xxxx xxxx
>> > FAX: (4xxx xxxx xxxx
>> >
>> >
>> > http://www.evsc.virginia.edu/faculty/people/mann.shtml
>> >
>> >
>> >
>
> ______________________________________________________________
> Professor Michael E. Mann
> Department of Environmental Sciences, Clark Hall
> University of Virginia
> Charlottesville, VA 22903
> _______________________________________________________________________
> e-mail: mann@xxxxxxxxx.xxx Phone: (4xxx xxxx xxxxFAX: (4xxx xxxx xxxx
> http://www.evsc.virginia.edu/faculty/people/mann.shtml
>
Hi Mike - of course we shouldn't make that assumption. If the issues are
being dealt with elsewhere in the peer-reviewed literature soon (in time
for IPCC to be aware of them) then there would be no reason for a
riposte in GRL. Even so, it might be worth putting the hypothetical case
to the Editor-in-Chief to test his response. Cheers, Malcolm
</x-flowed>
Original Filename: 1114785020.txt | Return to the index page | Permalink | Later Emails
From: Phil Jones <p.jones@xxxxxxxxx.xxx>
To: Ben Santer <santer1@xxxxxxxxx.xxx>
Subject: HC
Date: Fri Apr 29 10:30:xxx xxxx xxxx
Ben,
Tom was here yesterday. He said you were going to the CCSP meeting for a day
in Chicago, then flying on to the UK for the HC meeting May xxx xxxx xxxx(and 17th evening).
Do you still want to come on up to Norwich afterwards?
Glad to hear from Tom you've been writing up your CCSP chapter and extending
it significantly. He gave me a brief summary. I signed off yesterday on the CCSP
report. You should be getting it through Tom Karl later today, or by Monday. As I did
Ch 5, if you want to check anything with me feel free to. I wasn't able to stop some
comments being put in by Lindzen, but Tom has a paper as does Myles which are
enough to ignore his and the Douglass papers.
Cheers
Phil
Prof. Phil Jones
Climatic Research Unit Telephone +44 xxx xxxx xxxx
School of Environmental Sciences Fax +44 xxx xxxx xxxx
University of East Anglia
Norwich Email p.jones@xxxxxxxxx.xxx
NR4 7TJ
UK
----------------------------------------------------------------------------
Original Filename: 1196872660.txt | Return to the index page | Permalink | Later Emails
From: "Michael E. Mann" <mann@xxxxxxxxx.xxx>
To: Phil Jones <p.jones@xxxxxxxxx.xxx>
Subject: Re: [Fwd: Re: Even more on Loehle's 2000 year climate analysis]
Date: Wed, 05 Dec 2007 11:37:xxx xxxx xxxx
Reply-to: mann@xxxxxxxxx.xxx
well put Phil,
I think you've put your finger right on it. JGR-Atmospheres has been publishing some truly
awful papers lately; we responded (Gavin, me, James Annan) to the awful Schwartz
sensitivity estimate paper, but there are so many other bad papers that are appearing there
(Chylak, etc.) that its just impossible to respond to them all.
I hadn't seen this latest one though. McKitrick and Michaels team up again, wow! maybe
McKitrick has figured ou the difference between radians and degrees this time!
talk to you later,
mike
Phil Jones wrote:
Mike,
Also I see him writing things - then people saying you should
write this up for a paper, as though it can be knocked up in an
afternoon. He realises he can't do this - as it takes much longer.
Then we wastes more and more time opening up new threads.
He doesn't seem clever enough to realise this.
Gavin and Rasmus have seen the attached piece of garbage!
UAH is correct, therefore the land surface must be wrong.
Let's adjust it for a dodgy reason - ah, it now agrees with UAH.
Let's forget that the land now disagrees with the ocean surface.
If only I'd thought of that first, I could have not bothered with
the awful analysis. If only I'd just believed RSS in the first place.
Cheers
Phil
At 15:16 05/12/2007, you wrote:
HI Phil,
thanks--thats good.
Re, Loehle, McIntyre. Funny--w/ each awful paper E&E publishes, McIntyre realizes that
it compromises the integrity of his own "work" even further. He can't distance himself
from E&E much as he'd like to. He also seems to be losing lots of credibility now w/
all but his most loyal followers, which is good to see...
mike
Phil Jones wrote:
Mike,
Yes the 1990 graphic is in an Appendix. The last few are being regularly hassled
by Thorsten. The guy from EPRI (Larry) really wants something submitted soon.
So working here to get something in by end of Jan. Keith is going to get
it fast-tracked through the Holocene - well that's the plan.
The Loehle paper is awful as you know. So is another article on the IPCC process
in E&E. I did look at Climate Audit a week or two back - I got the impression
that McIntyre is trying to distance himself from some of these E&E articles by
saying we have to be equally skeptical about them as well.
Cheers
Phil
At 14:00 04/12/2007, you wrote:
Hey Phil,
thanks--nice coincidence in timing. So the 1990 graphic will be discussed in this review
paper, right? Perfect, I'll let Gavin know.
Will look into the AGU fellowship situation ASAP.
I don't read E&E, gives me indigestion--I don't even consider it peer-reviewed science,
and in my view we should treat it that way. i.e., don't cite, and if journalists ask us
about a paper, simply explain its not peer-reviewed science, and Sonja B-C, the editor,
has even admitted to an anti-Kyoto agenda!
I do hope that Wei-Chyung pursues legal action here.
So didn't see this recent paper, nor have I heard about the IJC paper, Christy and
Spencer continue to lose more and more scientific credibility with each awful paper they
publish.
Gavin is planning to do something on the Loehle paper on RealClimate, I'm staying away
from it. I have a revised set of hemispheric reconstructions which I'll send you soon,
its basically what I showed at AGU last year. Submitted to PNAS--more soon on that,
mike
Phil Jones wrote:
Mike,
Some text came last night from Caspar. Keith/Tim writing their parts still.
I have text from Francis, so almost all here now. Still need to find some time
- maybe the Christmas/New Year break here - to put it all together. There
is so much else going on here at the moment with other papers, it will
be hard to find some time. I wish they had all responded much sooner!
As for AGU - just getting one of their Fellowships would be fine.
I take it you've seen the attached in E&E. I've not heard any more from
Wei-Chyung in the past couple of months. I'm working on a paper
on urbanization. I can show China is hardly affected. Will send for you
to look over when I have it in a form that is sendable. Would appreciate
your thoughts on how I will have said things.
Have another awful pdf of a paper accepted in IJC !! It ws rejected
by all three reviewers for GRL! It is by Douglass, Christy , Singer et al
- thus you'll know what it is on.
Have booked flights for Tahiti in April, just need to do the hotel now.
Cheers
Phil
Cheers
Phil
At 02:07 04/12/2007, you wrote:
Hi Phil,
I hope things are going well these days, and that the recent round of attacks have died
down. seems like some time since I've heard from you.
Please see below: Gavin was wondering if there is any update in status on this?
By the way, still looking into nominating you for an AGU award, I've been told that the
Ewing medal wouldn't be the right one. Let me know if you have any particular options
you'd like me to investigate...
thanks,
mike
-------- Original Message --------
Subject: Re: Even more on Loehle's 2000 year climate analysis
Date: 03 Dec 2007 20:59:xxx xxxx xxxx
From: Gavin Schmidt [1]<gschmidt@xxxxxxxxx.xxx>
To: Michael E. Mann [2]<mann@xxxxxxxxx.xxx>
References: [3]<3.0.3.32.20071203130209.0123fd18@xxxxxxxxx.xxx>
[4]<3.0.3.32.20071202224717.012384a8@xxxxxxxxx.xxx>
[5]<3.0.3.32.20071201123550.01237954@xxxxxxxxx.xxx>
[6]<3.0.3.32.20071201123550.01237954@xxxxxxxxx.xxx>
[7]<3.0.3.32.20071202224717.012384a8@xxxxxxxxx.xxx>
[8]<3.0.3.32.20071203130209.0123fd18@xxxxxxxxx.xxx>
[9]<3.0.3.32.20071203141259.0126c33c@xxxxxxxxx.xxx>
[10]<475457F3.9070102@xxxxxxxxx.xxx>
this reminds me. What's the status of Phil Jones and Caspar's
investigation of the IPCC90 curve? Phil wanted us to hold off for some
reason, but is that done with?
That's a great story that needs to be told.
Gavin
On Mon, 2xxx xxxx xxxxat 14:24, Michael E. Mann wrote:
> thanks Eric,
>
> That's great. I've again copied in Gavin so that he has this info
too.
>
> Will keep you in the loop!
>
> mike
>
> Eric Swanson wrote:
> > Hi Mike,
> >
> > I do hope you all are able to put this all together.
> > There were several comments on CA about RealClimate,
suggesting
that
> > RC wouldn't say anything, as E&E publication has such a
bad
rap.
> >
> > Perhaps my biggest complaint was also one mentioned by another
> > poster
> > on CA. I don't like using a simple linear interpolation between
> > data points for these series where there are many years
between
> > samples.
> > Here's the other fellow's comments:
> >
> >
[11]
http://www.climateaudit.org/?p=2380#comment-162478
> >
[12]
http://www.climateaudit.org/?p=2380#comment-162654
> >
[13]
http://www.climateaudit.org/?p=2380#comment-162665
> >
> > I would go further than that. These data sets represent
samples
of
> > time records. The sampling does not produce a value for a
single
> > year.
> > Rather, each sample represents some number of years of the
variable
> > as averaged in the process of collecting the material to be
> > analyzed.
> >
> > Consider an ocean sediment core, such as Keigwin's data. The
> > subcores
> > are sampled every 1.0 cm. Assume the material is taken with a
device
> > that
> > collects mud from a 0.4 cm area along the core. Thus, the
sample
> > would
> > contain 4/10 of the material deposited at that 1 cm per sample
rate
> > of
> > change in time. If the age/depth model at that point yields a
100
> > year
> > per cm rate, then the sample would represent an average over
40
> > years.
> > Simple linear interpolation assumes a continuously varying
change
> > between
> > the points, while the sampling process would give a brief 40
year
> > value
> > with the other 60 years being unknown. What if the entire cm
of
the
> > core
> > were analyzed? One would not know unless one had contacted
each
> > research
> > group that did the analysis and requested more information
than
that
> > which
> > might be found in the published reports.
> >
> > NOTE: I looked at Keigwin's data when I wrote a comment on
Loehle's
> > 2004 paper
> >
> > Comments on "Climate change: detection and attribution of
trends
> > from long-term
> > geologic data" by C. Loehle [Ecological Modelling 171 (4)
(2004)
> > xxx xxxx xxxx],
> > Ecological Modelling 192 (20xxx xxxx xxxx
> >
> > You may add my name to the list for what it's worth.
> >
> > Best Regards,
> >
> > Eric Swanson
> > --------------------------------------------------------------
> > At 01:18 PM 12/3/xxx xxxx xxxx, you wrote:
> > >>>>
> > Eric--this is
great, thanks for all of the info. I've taken
> > the liberty of
forwarding to Gavin, as we're thinking of
> > doing an RC
post on this, and this would be very useful. We
> > should
certainly list you as a "co-author" on this, if thats
> > ok w/ you?
> >
> > Looking
forward
to hearing what else you find here!
> >
> > mike
> >
> >
>
>
>
> --
> Michael E. Mann
> Associate Professor
> Director, Earth System Science Center (ESSC)
>
> Department of
Meteorology
Phone: (8xxx xxxx xxxx
> 503 Walker
Building
FAX: (8xxx xxxx xxxx
> The Pennsylvania State University
email: [14]mann@xxxxxxxxx.xxx
> University Park, PA 16xxx xxxx xxxx
>
>
[15]
http://www.met.psu.edu/dept/faculty/mann.htm
>
--
Michael E. Mann
Associate Professor
Director, Earth System Science Center (ESSC)
Department of
Meteorology
Phone: (8xxx xxxx xxxx
503 Walker
Building
FAX: (8xxx xxxx xxxx
The Pennsylvania State University
email: [16]mann@xxxxxxxxx.xxx
University Park, PA 16xxx xxxx xxxx
[17]
http://www.met.psu.edu/dept/faculty/mann.htm
Prof. Phil Jones
Climatic Research Unit Telephone +44 xxx xxxx xxxx
School of Environmental Sciences Fax +44 xxx xxxx xxxx
University of East Anglia
Norwich Email [18]p.jones@xxxxxxxxx.xxx
NR4 7TJ
UK
----------------------------------------------------------------------------
--
Michael E. Mann
Associate Professor
Director, Earth System Science Center (ESSC)
Department of
Meteorology
Phone: (8xxx xxxx xxxx
503 Walker
Building
FAX: (8xxx xxxx xxxx
The Pennsylvania State University
email: [19]mann@xxxxxxxxx.xxx
University Park, PA 16xxx xxxx xxxx
[20]
http://www.met.psu.edu/dept/faculty/mann.htm
Prof. Phil Jones
Climatic Research Unit Telephone +44 xxx xxxx xxxx
School of Environmental Sciences Fax +44 xxx xxxx xxxx
University of East Anglia
Norwich Email [21]p.jones@xxxxxxxxx.xxx
NR4 7TJ
UK
----------------------------------------------------------------------------
--
Michael E. Mann
Associate Professor
Director, Earth System Science Center (ESSC)
Department of
Meteorology
Phone: (8xxx xxxx xxxx
503 Walker
Building
FAX: (8xxx xxxx xxxx
The Pennsylvania State University
email: [22]mann@xxxxxxxxx.xxx
University Park, PA 16xxx xxxx xxxx
[23]
http://www.met.psu.edu/dept/faculty/mann.htm
Prof. Phil Jones
Climatic Research Unit Telephone +44 xxx xxxx xxxx
School of Environmental Sciences Fax +44 xxx xxxx xxxx
University of East Anglia
Norwich Email [24]p.jones@xxxxxxxxx.xxx
NR4 7TJ
UK
----------------------------------------------------------------------------
--
Michael E. Mann
Associate Professor
Director, Earth System Science Center (ESSC)
Department of Meteorology Phone: (8xxx xxxx xxxx
503 Walker Building FAX: (8xxx xxxx xxxx
The Pennsylvania State University email: [25]mann@xxxxxxxxx.xxx
University Park, PA 16xxx xxxx xxxx
[26]http://www.met.psu.edu/dept/faculty/mann.htm
References
Visible links
1. mailto:gschmidt@xxxxxxxxx.xxx
2. mailto:mann@xxxxxxxxx.xxx
3. mailto:3.0.3.32.20071203130209.0123fd18@xxxxxxxxx.xxx
4. mailto:3.0.3.32.20071202224717.012384a8@xxxxxxxxx.xxx
5. mailto:3.0.3.32.20071201123550.01237954@xxxxxxxxx.xxx
6. mailto:3.0.3.32.20071201123550.01237954@xxxxxxxxx.xxx
7. mailto:3.0.3.32.20071202224717.012384a8@xxxxxxxxx.xxx
8. mailto:3.0.3.32.20071203130209.0123fd18@xxxxxxxxx.xxx
9. mailto:3.0.3.32.20071203141259.0126c33c@xxxxxxxxx.xxx
10. mailto:475457F3.9070102@xxxxxxxxx.xxx
11. http://www.climateaudit.org/?p=2380#comment-162478
12. http://www.climateaudit.org/?p=2380#comment-162654
13. http://www.climateaudit.org/?p=2380#comment-162665
14. mailto:mann@xxxxxxxxx.xxx
15. http://www.met.psu.edu/dept/faculty/mann.htm
16. mailto:mann@xxxxxxxxx.xxx
17. http://www.met.psu.edu/dept/faculty/mann.htm
18. mailto:p.jones@xxxxxxxxx.xxx
19. mailto:mann@xxxxxxxxx.xxx
20. http://www.met.psu.edu/dept/faculty/mann.htm
21. mailto:p.jones@xxxxxxxxx.xxx
22. mailto:mann@xxxxxxxxx.xxx
23. http://www.met.psu.edu/dept/faculty/mann.htm
24. mailto:p.jones@xxxxxxxxx.xxx
25. mailto:mann@xxxxxxxxx.xxx
26. http://www.met.psu.edu/dept/faculty/mann.htm
Hidden links:
27. http://www.met.psu.edu/dept/faculty/mann.htm
Original Filename: 1196877845.txt | Return to the index page | Permalink | Later Emails
From: Ben Santer <santer1@xxxxxxxxx.xxx>
To: Peter Thorne <peter.thorne@xxxxxxxxx.xxx>
Subject: Re: [Fwd: sorry to take your time up, but really do need a scrub of this singer/christy/etc effort]
Date: Wed, 05 Dec 2007 13:04:xxx xxxx xxxx
Reply-to: santer1@xxxxxxxxx.xxx
Cc: Carl Mears <mears@xxxxxxxxx.xxx>, Leopold Haimberger <leopold.haimberger@xxxxxxxxx.xxx>, Karl Taylor <taylor13@xxxxxxxxx.xxx>, Tom Wigley <wigley@xxxxxxxxx.xxx>, Phil Jones <p.jones@xxxxxxxxx.xxx>, Tom Wigley <wigley@xxxxxxxxx.xxx>, Steve Sherwood <Steven.Sherwood@xxxxxxxxx.xxx>, John Lanzante <John.Lanzante@xxxxxxxxx.xxx>, Dian Seidel <dian.seidel@xxxxxxxxx.xxx>, Melissa Free <melissa.free@xxxxxxxxx.xxx>, Frank Wentz <frank.wentz@xxxxxxxxx.xxx>, Steve Klein <klein21@xxxxxxxxx.xxx>
<x-flowed>
Dear folks,
Thank you very much for all of your emails, and my apologies for the
delay in replying - I've been on travel for much of the past week.
Peter, I think you've done a nice job in capturing some of my concerns
about the Douglass et al. paper. Our CCSP Report helped to illustrate
that there were large structural uncertainties in both the radiosonde-
and MSU-based estimates of tropospheric temperature change. The
scientific evidence available at the time we were finalizing the CCSP
Report - from Sherwood et al. (2005) and the (then-unpublished) Randel
and Wu paper - strongly suggested that a residual cooling bias existed
in the sonde-based estimates of tropospheric temperature change.
As you may recall, we showed results from both the RATPAC and HadAT2
radiosonde datasets in the CCSP Report and the Santer et al. (2005)
Science paper. From the latter (see, e.g., our Figure 3B and Figures
4C,D), it was clear that there were physically-significant differences
between the simulated temperature trends in the tropical lower
troposphere (over 1979 to 1999) and the trends estimated from RATPAC,
HadAT2, and UAH data. In both the Science paper and the CCSP Report, we
judged that residual biases in the observations provided the most likely
explanation for these model-versus-data trend discrepancies.
Douglass et al. come to a fundamentally different conclusion, and
ascribe model-versus-data differences to model error. They are not
really basing this conclusion on new model data or on new observational
data. The only "new" observational dataset that they use is an early
version of Leo Haimberger's radiosonde dataset (RAOBCORE v1.2). Leo's
dataset was under development at the time all of us were working on the
CCSP Report and the Santer et al. Science paper. It was not available
for our assessment in 2005. As Leo has already shared with you, newer
versions of RAOBCORE (v1.3 and v1.4) show amplification of surface
warming in the tropical troposphere, in reasonable agreement with the
model results that we presented in Fig. 3B of our Science paper.
Douglass et al. did not use these newer versions of RAOBCORE v1.2. Nor
did Douglass et al. use any "inconvenient" observational datasets (such
as the NESDIS-based MSU T2 dataset of Zou et al., or the MSU T2 product
of Vinnikov and Grody) showing pronounced tropospheric warming over the
satellite era. Nor did Douglass et al. discuss the "two timescale issue"
that formed an important part of our Science paper (i.e., how could
models and multiple observational datasets show amplification behavior
that was consistent in terms of monthly variability but inconsistent in
terms of decadal trends?) Nor did Douglass et al. fairly portray results
from Peter's 2007 GRL paper. In my personal opinion, Douglass et al.
have ignored all scientific evidence that is in disagreement with their
view of how the real world should be behaving.
I don't think it's a good strategy to submit a response to the Douglass
et al. paper to the International Journal of Climatology (IJC). As Phil
pointed out, IJC has a large backlog, so it might take some time to get
a response published. Furthermore, Douglass et al. probably would be
given the final word.
My suggestion is to submit (to Science) a short "update" of our 2005
paper. This update would only be submitted AFTER publication of the four
new radiosonde-based temperature datasets mentioned by Peter. The update
would involve:
1) Use of all four new radiosonde datasets.
2) Use of the latest versions of the UAH and RSS TLT data, and the
latest versions of the T2 data from UAH, RSS, UMD (Vinnikov and Grody),
and NESDIS (Zou et al.).
3) Use of the T2 data in 2) above AND the UAH and RSS T4 data to
calculate tropical "TFu" temperatures, with all possible combinations of
T4 and T2 datasets (e.g., RSS T4 and UMD T2, UAH T4 and UMD T2, etc.)
4) Calculating synthetic MSU temperatures from all model 20c3m runs
currently available in the IPCC AR4 database. Calculation of synthetic
MSU temperatures would rely on a method suggested by Carl (using
weighting functions that depend on both the surface type [land, ocean]
and the surface pressure at each grid-point) rather than on the static
global-mean weighting function that we used previously. This is probably
several months of work - but at least it will keep me off the streets
and out of trouble.
5) Formal determination of statistical significance of
model-versus-observed trend differences.
6) Brief examination of timescale-dependence of amplification factors.
7) As and both Peter and Melissa suggested, brief examination of
sensitivity of estimated trends to the selected analysis period (e.g.,
use of 1979 to 1999; use of 1979 to 2001 or 2003 [for the small number
of model 20c3m runs ending after 1999]; use of data for the post-NOAA9
period).
This will be a fair bit of effort, but I think it's worth it. Douglass
et al. will try to make maximum political hay out of their IJC paper -
which has already been sent to Andy Revkin at the New York Times. You
can bet they've sent it elsewhere, too. I'm pretty sure that our
colleague JC will portray Douglass et al. as definitive "proof" that all
climate models are fundamentally flawed, UAH data are in amazing
agreement with sonde-based estimates of tropospheric temperature change,
global warming is not a serious problem, etc.
One of the most disturbing aspects of Douglass et al. is its abrupt
dismissal of the finding (by Sherwood et al. and Randel and Wu) of a
residual tropospheric cooling bias in the sonde data. Douglass et al.
base this dismissal on the Christy et al. (2007) JGR paper, and on
Christy's finding of biases in the night-time sonde data that magically
offset the biases in the day-time data. Does that sound familiar? When
did we last hear about new biases magically offsetting the effect of
recently-discovered biases? As Yogi Berra would say, this is deja vu all
over again....
I hope that one of the papers on the new sonde-based datasets directly
addresses the subject of 'error compensation' in the day-time and
night-time sonde data. This would be important to do.
It's unfortunate that Douglass et al. will probably be published well
before the appearance of the papers on the new radiosonde datasets, and
before an updated comparison of modeled-and observed tropospheric
temperature trends.
I'd be grateful if you could let me know whether you are in agreement
with the response strategy I've outlined above, and would like to be
involved with an update of our 2005 Science paper.
With best regards,
Ben
Peter Thorne wrote:
> All,
>
> There are several additional reasons why we may not expect perfect
> agreement between models and obs that are outlined in the attached
> paper.
>
> It speaks in part to the trend uncertainty that Carl alluded to - taking
> differences between linear trend estimates is hard when the underlying
> series is noisy and perhaps non-linear. Work that John and Dian have
> done also shows this. Taking the ratio between two such estimates is
> always going to produce noisy results over relatively short trend
> periods when the signal is small relative to the natural variability.
>
> Also, 1979 as a start date may bias those estimates towards a "bias", I
> believe (this is unproven) because of endpoint effects due to natural
> variability that tend to damp the ratio of Trop/Surf trends (ENSO
> phasing and El Chichon) for any trend period with this start date. Given
> the N-9 uncertainty a reasonable case could be made for an evaluation of
> the obs that started only after N-9 and this may yield a very different
> picture.
>
> It also shows that the model result really is constrained to perturbed
> physics, at least for HadCM3. Unsurprising as convective adjustment is
> at the heart of most models. Certainly ours anyway. This result was
> cherry-picked and the rest of the paper discarded by Douglass et al.
>
> In addition to this, the state of play on the radiosondes has moved on
> substantially with RAOBCORE 1.4 (accepted I believe, Leo Haimberger
> should be in this - I'm adding him) which shows warming intermediate
> between UAH and RSS and I know of three additional efforts on
> radiosondes all of which strongly imply that the raobs datasets used in
> this paper are substantially under-estimating the warming rate (Steve
> Sherwood x2 and our automated system). So, there's going to be a whole
> suite of papers hopefully coming out within the next year or so that
> imply we at least cannot rule out from the radiosonde data warming
> consistent even with the absurd "mean of the model runs" criteria that
> is used in this paper.
>
> For info, our latest results imply a true raobs trend for 2LT in the
> tropics somewhere >0.08K/decade (we cannot place a defensible upper
> limit) ruling out most of the datasets used in the Douglass paper and
> ruling in possibility of consistency with models.
>
> Douglass et al also omit the newer MSU studies from the NESDIS group
> which in the absence of a reasonable criteria (a criteria I think we are
> some way away from still) to weed out bad obs datasets should be
> considered. Placing all obs datasets and the likely new raobs datasets
> would pretty much destroy this paper's main point. There's been a fair
> bit of cherry picking on the obs side which needs correcting here.
>
> Peter
>
> On Tue, 2xxx xxxx xxxxat 15:xxx xxxx xxxx, carl mears wrote:
>> Karl -- thanks for clarifying what I was trying to say
>>
>> Some further comments.....
>>
>> At 02:53 PM 12/4/2007, Karl Taylor wrote:
>>> Dear all,
>>> 2) unforced variability hasn't dominated the observations.
>> But on this short time scale, we strongly suspect that it has
>> dominated. For example, the
>> 2 sigma error bars from table 3.4, CCSP for satellite TLT are 0.18 (UAH) or
>> 0.19 (RSS), larger
>> than either group's trends (0.05, 0.15) for 1xxx xxxx xxxx. These were
>> calculated using a "goodness
>> of linear fit" criterion, corrected for autocorrelation. This is a
>> probably a reasonable
>> estimate of the contribution of unforced variability to trend uncertainty.
>>
>>
>>
>>> Douglass et al. have *not* shown that every individual model is in fact
>>> inconsistent with the observations. If the spread of individual model
>>> results is large enough and at least 1 model overlaps the observations,
>>> then one cannot claim that all models are wrong, just that the mean is biased.
>>
>> Given the magnitude of the unforced variability, I would say "the mean
>> *may* be biased." You can't prove this
>> with only one universe, as Tom alluded. All we can say is that the
>> observed trend cannot be proven to
>> be inconsistent with the model results, since it is inside their range.
>>
>> It we interesting to see if we can say anything more, when we start culling
>> out the less realistic models,
>> as Ben has suggested.
>>
>> -Carl
>>
>>
>>
>>
--
----------------------------------------------------------------------------
Benjamin D. Santer
Program for Climate Model Diagnosis and Intercomparison
Lawrence Livermore National Laboratory
P.O. Box 808, Mail Stop L-103
Livermore, CA 94550, U.S.A.
Tel: (9xxx xxxx xxxx
FAX: (9xxx xxxx xxxx
email: santer1@xxxxxxxxx.xxx
----------------------------------------------------------------------------
</x-flowed>
Original Filename: 1196882357.txt | Return to the index page | Permalink | Later Emails
From: Ben Santer <santer1@xxxxxxxxx.xxx>
To: Phil Jones <p.jones@xxxxxxxxx.xxx>
Subject: Re: [Fwd: sorry to take your time up, but really do need a scrub of this singer/christy/etc effort]
Date: Wed, 05 Dec 2007 14:19:xxx xxxx xxxx
Reply-to: santer1@xxxxxxxxx.xxx
Cc: carl mears <mears@xxxxxxxxx.xxx>, Karl Taylor <taylor13@xxxxxxxxx.xxx>, Tom Wigley <wigley@xxxxxxxxx.xxx>, Tom Wigley <wigley@xxxxxxxxx.xxx>, "Thorne, Peter" <peter.thorne@xxxxxxxxx.xxx>, Steven Sherwood <Steven.Sherwood@xxxxxxxxx.xxx>, John Lanzante <John.Lanzante@xxxxxxxxx.xxx>, "'Dian J. Seidel'" <dian.seidel@xxxxxxxxx.xxx>, Melissa Free <Melissa.Free@xxxxxxxxx.xxx>, Frank Wentz <frank.wentz@xxxxxxxxx.xxx>, Steve Klein <klein21@xxxxxxxxx.xxx>, Leopold Haimberger <leopold.haimberger@xxxxxxxxx.xxx>, peter gleckler <gleckler1@xxxxxxxxx.xxx>
<x-flowed>
Dear Phil,
Just a quick response to the issue of "model weighting" which you and
Carl raised in your emails.
We recently published a paper dealing with the identification of an
anthropogenic fingerprint in SSM/I-based estimates of total column water
vapor changes. This was a true multi-model detection and attribution
("D&A") study, which made use of results from 22 different A/OGCMs for
fingerprint and noise estimation. Together with Peter Gleckler and Karl
Taylor, I'm now in the process of repeating our water vapor D&A study
using a subset of the original 22 models. This subset will comprise
xxx xxxx xxxxmodels which are demonstrably more successful in capturing
features of the observed mean state and variability of water vapor and
SST - particularly features crucial to the D&A problem (such as the
low-frequency variability). We've had fun computing a whole range of
metrics that might be used to define such a subset of "better" models.
The ultimate goal is to determine the sensitivity of our water vapor D&A
results to model quality. I think that this kind of analysis will be
unavoidable in the multi-model world in which we now live. Given
substantial inter-model differences in simulation quality, "one model,
one vote" is probably not the best policy for D&A work!
Once we've used Carl's method to calculate synthetic MSU temperatures
from the IPCC AR4 20c3m data (as described in my previous email), it
should be relatively easy to do a similar "model culling" exercise with
MSU T2, T4, and TLT. In fact, this is what we had already planned to do
in collaboration with Carl and Frank.
One key point in any model weighting or selection strategy is to avoid
circularity. In the D&A context, it would be impermissible to include
information on trend behavior as a criterion used for selecting "better"
models. Likewise, if our interest is in assessing the statistical
significance of model-versus-observed trend differences, we can't use
model performance in simulating "observed" tropospheric or stratospheric
trends (whatever those might be!) as a means of identifying more
credible models.
A further issue, of course, is that we are relying on results from fully
coupled A/OGCMs, and are making trend comparisons over relatively short
periods (several decades). On these short timescales, estimates of the
"true" trend in response to the applied 20c3m forcings are quite
sensitive to natural variability noise (as Peter Thorne's 2007 GRL paper
clearly illustrates). Because of such chaotic variability, even a
hypothetical model with perfect physics and forcings would yield a
distribution of tropospheric temperature trends over 1979 to 1999, some
of which would show larger or smaller cooling than observed. This is why
it's illogical to stratify model results according to correspondence
between modeled and observed surface warming - something which John
Christy is very fond of doing.
What we've done (in the new water vapor work described above) is to
evaluate the fidelity with which the AR4 models simulate the observed
mean state and variability of precipitable water and SST - not the
trends in these quantities. We've looked at a model performance in a
variety of different regions, and on multiple timescales. The results
are fascinating, and show (at least for water vapor and SST) that every
model has its own individual strengths and weaknesses. It is difficult
to identify a subset of models that CONSISTENTLY does well in many
different regions and over a range of different timescales.
My guess is that we would obtain somewhat different results for MSU
temperatures - particularly for comparisons involving variability.
Clearly, the absence of volcanic forcing in roughly half of the 20c3m
experiments will have a large impact on the estimated variability of
synthetic T4 temperatures (and perhaps even on T2), and hence on
model-versus-data variability comparisons. It's also quite possible that
the inclusion or absence of volcanic forcing has an impact not only on
the amplitude of the variability of global-mean T4 anomalies, but also
on the pattern of T4 variability. So model ranking exercises based on
performance in simulating the mean state and variability of T4 and T2
may show some connection to the presence or absence of volcanic/ozone
forcing.
The sad thing is we are being distracted from doing this fun stuff by
the need to respond to Douglass et al. That's a real shame.
With best regards,
Ben
Phil Jones wrote:
> All,
> IJC do have comments but only very rarely. I see little point in
> doing this
> as there is likely to be a word limit, and if the system works properly
> Douglass et al would get the final say. There is also a large backlog in
> papers awaiting to appear, so even if the comment were accepted it would
> be some time after Douglass et al that it would appear.
> Better would be a submission to another journal (JGR?) which
> would be quicker. This could go in before Douglass et al appeared in
> print - it should be in the IJC early online view fairly soon based on
> recent experiences.
> A paper pointing out the issues of trying to weight models in some way
> would be very beneficial to the community. AR5 will have to go down this
> route at some point. How models simulate the
> recent trends at the surface and in the troposphere/stratosphere and
> how they might be ranked is a possibility. This could bring in the
> new work Peter alludes to with the sondes.
> There are also some aspects of recent surface T changes that could be
> discussed as well. These relate to the growing dominance of buoy SSTs
> (now 70% of the total) vs conventional ships. There is a paper in J.
> Climate
> accepted from Smith/Reynolds et al at NCDC, which show that buoys
> could conceivably be cooler than ship-based SST by about 0.1C - meaning
> that the last xxx xxxx xxxxyears are being gradually underestimated over the
> oceans.
> Overlap is still too short to be confident about this, but it highlights a
> major systematic change occurring in surface ocean measurements. As the
> buoys are presumably better for absolute SSTs, this means models
> driven with fixed SSTs should be using fields that are marginally cooler.
>
> And then there is the continual reference to Kalnay and Cai, when
> Simmons et al (2004) have shown the problems with NCEP. It is possible
> to add in the ERA-Interim analyses and operational analyses to
> being results from ERA-40 up to date.
>
> Cheers
> Phil
>
>
> At 23:40 04/12/2007, carl mears wrote:
>> Karl -- thanks for clarifying what I was trying to say
>>
>> Some further comments.....
>>
>> At 02:53 PM 12/4/2007, Karl Taylor wrote:
>>> Dear all,
>>> 2) unforced variability hasn't dominated the observations.
>>
>> But on this short time scale, we strongly suspect that it has
>> dominated. For example, the
>> 2 sigma error bars from table 3.4, CCSP for satellite TLT are 0.18
>> (UAH) or 0.19 (RSS), larger
>> than either group's trends (0.05, 0.15) for 1xxx xxxx xxxx. These were
>> calculated using a "goodness
>> of linear fit" criterion, corrected for autocorrelation. This is a
>> probably a reasonable
>> estimate of the contribution of unforced variability to trend
>> uncertainty.
>>
>>
>>
>>> Douglass et al. have *not* shown that every individual model is in
>>> fact inconsistent with the observations. If the spread of individual
>>> model results is large enough and at least 1 model overlaps the
>>> observations, then one cannot claim that all models are wrong, just
>>> that the mean is biased.
>>
>>
>> Given the magnitude of the unforced variability, I would say "the mean
>> *may* be biased." You can't prove this
>> with only one universe, as Tom alluded. All we can say is that the
>> observed trend cannot be proven to
>> be inconsistent with the model results, since it is inside their range.
>>
>> It we interesting to see if we can say anything more, when we start
>> culling out the less realistic models,
>> as Ben has suggested.
>>
>> -Carl
>>
>>
>>
>>
>
> Prof. Phil Jones
> Climatic Research Unit Telephone +44 xxx xxxx xxxx
> School of Environmental Sciences Fax +44 xxx xxxx xxxx
> University of East Anglia
> Norwich Email p.jones@xxxxxxxxx.xxx
> NR4 7TJ
> UK
> ----------------------------------------------------------------------------
>
--
----------------------------------------------------------------------------
Benjamin D. Santer
Program for Climate Model Diagnosis and Intercomparison
Lawrence Livermore National Laboratory
P.O. Box 808, Mail Stop L-103
Livermore, CA 94550, U.S.A.
Tel: (9xxx xxxx xxxx
FAX: (9xxx xxxx xxxx
email: santer1@xxxxxxxxx.xxx
----------------------------------------------------------------------------
</x-flowed>
Original Filename: 1196956362.txt | Return to the index page | Permalink | Later Emails
From: Ben Santer <santer1@xxxxxxxxx.xxx>
To: Melissa Free <Melissa.Free@xxxxxxxxx.xxx>
Subject: Re: [Fwd: sorry to take your time up, but really do need a scrub of this singer/christy/etc effort]
Date: Thu, 06 Dec 2007 10:52:xxx xxxx xxxx
Reply-to: santer1@xxxxxxxxx.xxx
Cc: Phil Jones <p.jones@xxxxxxxxx.xxx>, carl mears <mears@xxxxxxxxx.xxx>, Karl Taylor <taylor13@xxxxxxxxx.xxx>, Tom Wigley <wigley@xxxxxxxxx.xxx>, Tom Wigley <wigley@xxxxxxxxx.xxx>, "Thorne, Peter" <peter.thorne@xxxxxxxxx.xxx>, Steven Sherwood <Steven.Sherwood@xxxxxxxxx.xxx>, John Lanzante <John.Lanzante@xxxxxxxxx.xxx>, "'Dian J. Seidel'" <dian.seidel@xxxxxxxxx.xxx>, Frank Wentz <frank.wentz@xxxxxxxxx.xxx>, Steve Klein <klein21@xxxxxxxxx.xxx>, Leopold Haimberger <leopold.haimberger@xxxxxxxxx.xxx>, peter gleckler <gleckler1@xxxxxxxxx.xxx>
<x-flowed>
Dear Melissa,
No, this would not be dire. What is dire is Douglass et al.'s willful
neglect of any observational datasets that do not support their
arguments. Recall that our 2005 Science paper presented information from
all observational datasets available to us at that time, even from
datasets that showed large differences relative to the model data. We
did not present results from RSS alone.
With best regards,
Ben
Melissa Free wrote:
> One further question about the Douglass paper: What about the
> implications of a real model-observation difference for upper-air
> trends? Is this really so dire?
> -Melissa
>
--
----------------------------------------------------------------------------
Benjamin D. Santer
Program for Climate Model Diagnosis and Intercomparison
Lawrence Livermore National Laboratory
P.O. Box 808, Mail Stop L-103
Livermore, CA 94550, U.S.A.
Tel: (9xxx xxxx xxxx
FAX: (9xxx xxxx xxxx
email: santer1@xxxxxxxxx.xxx
----------------------------------------------------------------------------
</x-flowed>
Original Filename: 1196964260.txt | Return to the index page | Permalink | Later Emails
From: Dian Seidel <dian.seidel@xxxxxxxxx.xxx>
To: santer1@xxxxxxxxx.xxx
Subject: Re: [Fwd: sorry to take your time up, but really do need a scrub of this singer/christy/etc effort]
Date: Thu, 06 Dec 2007 13:04:xxx xxxx xxxx
Cc: Phil Jones <p.jones@xxxxxxxxx.xxx>, carl mears <mears@xxxxxxxxx.xxx>, Karl Taylor <taylor13@xxxxxxxxx.xxx>, Tom Wigley <wigley@xxxxxxxxx.xxx>, Tom Wigley <wigley@xxxxxxxxx.xxx>, "Thorne, Peter" <peter.thorne@xxxxxxxxx.xxx>, Steven Sherwood <Steven.Sherwood@xxxxxxxxx.xxx>, John Lanzante <John.Lanzante@xxxxxxxxx.xxx>, Melissa Free <Melissa.Free@xxxxxxxxx.xxx>, Frank Wentz <frank.wentz@xxxxxxxxx.xxx>, Steve Klein <klein21@xxxxxxxxx.xxx>, Leopold Haimberger <leopold.haimberger@xxxxxxxxx.xxx>, peter gleckler <gleckler1@xxxxxxxxx.xxx>
<x-flowed>
Hello Ben and Colleagues,
I've been following these exchanges with interest. One particular point
in your message below is a little puzzling to me. That's the issue of
trying to avoid circularity in the culling of models for any given D&A
study.
Two potential problems occur to me. One is that choosing models on the
basis of their fidelity to observed regional and short term variability
may not be completely orthogonal to choosing based on long-term trend.
That's because those smaller scale changes may contribute to the trends
and their patterns. Second, choosing a different set of models for one
variable (temperature) than for another (humidity) seems highly
problematic. If we are interested in projections of other variables,
e.g. storm tracks or cloud cover, for which D&A has not been done, which
group of models would we then deem to be most credible? I don't have a
good alternative to propose, but, in light of these considerations,
maybe one-model-one-vote doesn't appear so unreasonable after all.
With regards,
Dian
Ben Santer wrote:
> Dear Phil,
>
> Just a quick response to the issue of "model weighting" which you and
> Carl raised in your emails.
>
> We recently published a paper dealing with the identification of an
> anthropogenic fingerprint in SSM/I-based estimates of total column
> water vapor changes. This was a true multi-model detection and
> attribution ("D&A") study, which made use of results from 22 different
> A/OGCMs for fingerprint and noise estimation. Together with Peter
> Gleckler and Karl Taylor, I'm now in the process of repeating our
> water vapor D&A study using a subset of the original 22 models. This
> subset will comprise xxx xxxx xxxxmodels which are demonstrably more
> successful in capturing features of the observed mean state and
> variability of water vapor and SST - particularly features crucial to
> the D&A problem (such as the low-frequency variability). We've had fun
> computing a whole range of metrics that might be used to define such a
> subset of "better" models. The ultimate goal is to determine the
> sensitivity of our water vapor D&A results to model quality. I think
> that this kind of analysis will be unavoidable in the multi-model
> world in which we now live. Given substantial inter-model differences
> in simulation quality, "one model, one vote" is probably not the best
> policy for D&A work!
>
> Once we've used Carl's method to calculate synthetic MSU temperatures
> from the IPCC AR4 20c3m data (as described in my previous email), it
> should be relatively easy to do a similar "model culling" exercise
> with MSU T2, T4, and TLT. In fact, this is what we had already planned
> to do in collaboration with Carl and Frank.
>
> One key point in any model weighting or selection strategy is to avoid
> circularity. In the D&A context, it would be impermissible to include
> information on trend behavior as a criterion used for selecting
> "better" models. Likewise, if our interest is in assessing the
> statistical significance of model-versus-observed trend differences,
> we can't use model performance in simulating "observed" tropospheric
> or stratospheric trends (whatever those might be!) as a means of
> identifying more credible models.
>
> A further issue, of course, is that we are relying on results from
> fully coupled A/OGCMs, and are making trend comparisons over
> relatively short periods (several decades). On these short timescales,
> estimates of the "true" trend in response to the applied 20c3m
> forcings are quite sensitive to natural variability noise (as Peter
> Thorne's 2007 GRL paper clearly illustrates). Because of such chaotic
> variability, even a hypothetical model with perfect physics and
> forcings would yield a distribution of tropospheric temperature trends
> over 1979 to 1999, some of which would show larger or smaller cooling
> than observed. This is why it's illogical to stratify model results
> according to correspondence between modeled and observed surface
> warming - something which John Christy is very fond of doing.
>
> What we've done (in the new water vapor work described above) is to
> evaluate the fidelity with which the AR4 models simulate the observed
> mean state and variability of precipitable water and SST - not the
> trends in these quantities. We've looked at a model performance in a
> variety of different regions, and on multiple timescales. The results
> are fascinating, and show (at least for water vapor and SST) that
> every model has its own individual strengths and weaknesses. It is
> difficult to identify a subset of models that CONSISTENTLY does well
> in many different regions and over a range of different timescales.
>
> My guess is that we would obtain somewhat different results for MSU
> temperatures - particularly for comparisons involving variability.
> Clearly, the absence of volcanic forcing in roughly half of the 20c3m
> experiments will have a large impact on the estimated variability of
> synthetic T4 temperatures (and perhaps even on T2), and hence on
> model-versus-data variability comparisons. It's also quite possible
> that the inclusion or absence of volcanic forcing has an impact not
> only on the amplitude of the variability of global-mean T4 anomalies,
> but also on the pattern of T4 variability. So model ranking exercises
> based on performance in simulating the mean state and variability of
> T4 and T2 may show some connection to the presence or absence of
> volcanic/ozone forcing.
>
> The sad thing is we are being distracted from doing this fun stuff by
> the need to respond to Douglass et al. That's a real shame.
>
> With best regards,
>
> Ben
>
> Phil Jones wrote:
>> All,
>> IJC do have comments but only very rarely. I see little point in
>> doing this
>> as there is likely to be a word limit, and if the system works properly
>> Douglass et al would get the final say. There is also a large
>> backlog in
>> papers awaiting to appear, so even if the comment were accepted it
>> would
>> be some time after Douglass et al that it would appear.
>> Better would be a submission to another journal (JGR?) which
>> would be quicker. This could go in before Douglass et al appeared in
>> print - it should be in the IJC early online view fairly soon based on
>> recent experiences.
>> A paper pointing out the issues of trying to weight models in some
>> way
>> would be very beneficial to the community. AR5 will have to go down
>> this
>> route at some point. How models simulate the
>> recent trends at the surface and in the troposphere/stratosphere and
>> how they might be ranked is a possibility. This could bring in the
>> new work Peter alludes to with the sondes.
>> There are also some aspects of recent surface T changes that could be
>> discussed as well. These relate to the growing dominance of buoy SSTs
>> (now 70% of the total) vs conventional ships. There is a paper in J.
>> Climate
>> accepted from Smith/Reynolds et al at NCDC, which show that buoys
>> could conceivably be cooler than ship-based SST by about 0.1C - meaning
>> that the last xxx xxxx xxxxyears are being gradually underestimated over the
>> oceans.
>> Overlap is still too short to be confident about this, but it
>> highlights a
>> major systematic change occurring in surface ocean measurements. As the
>> buoys are presumably better for absolute SSTs, this means models
>> driven with fixed SSTs should be using fields that are marginally
>> cooler.
>>
>> And then there is the continual reference to Kalnay and Cai, when
>> Simmons et al (2004) have shown the problems with NCEP. It is possible
>> to add in the ERA-Interim analyses and operational analyses to
>> being results from ERA-40 up to date.
>>
>> Cheers
>> Phil
>>
>>
>> At 23:40 04/12/2007, carl mears wrote:
>>> Karl -- thanks for clarifying what I was trying to say
>>>
>>> Some further comments.....
>>>
>>> At 02:53 PM 12/4/2007, Karl Taylor wrote:
>>>> Dear all,
>>>> 2) unforced variability hasn't dominated the observations.
>>>
>>> But on this short time scale, we strongly suspect that it has
>>> dominated. For example, the
>>> 2 sigma error bars from table 3.4, CCSP for satellite TLT are 0.18
>>> (UAH) or 0.19 (RSS), larger
>>> than either group's trends (0.05, 0.15) for 1xxx xxxx xxxx. These were
>>> calculated using a "goodness
>>> of linear fit" criterion, corrected for autocorrelation. This is a
>>> probably a reasonable
>>> estimate of the contribution of unforced variability to trend
>>> uncertainty.
>>>
>>>
>>>
>>>> Douglass et al. have *not* shown that every individual model is in
>>>> fact inconsistent with the observations. If the spread of
>>>> individual model results is large enough and at least 1 model
>>>> overlaps the observations, then one cannot claim that all models
>>>> are wrong, just that the mean is biased.
>>>
>>>
>>> Given the magnitude of the unforced variability, I would say "the
>>> mean *may* be biased." You can't prove this
>>> with only one universe, as Tom alluded. All we can say is that the
>>> observed trend cannot be proven to
>>> be inconsistent with the model results, since it is inside their range.
>>>
>>> It we interesting to see if we can say anything more, when we start
>>> culling out the less realistic models,
>>> as Ben has suggested.
>>>
>>> -Carl
>>>
>>>
>>>
>>>
>>
>> Prof. Phil Jones
>> Climatic Research Unit Telephone +44 xxx xxxx xxxx
>> School of Environmental Sciences Fax +44 xxx xxxx xxxx
>> University of East Anglia
>> Norwich Email p.jones@xxxxxxxxx.xxx
>> NR4 7TJ
>> UK
>> ----------------------------------------------------------------------------
>>
>
>
--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dian J. Seidel
NOAA Air Resources Laboratory (R/ARL)
1315 East West Highway
Silver Spring, MD 20910
Dian.Seidel@xxxxxxxxx.xxx
Phone: xxx xxxx xxxxext. 126
Fax: xxx xxxx xxxx
http://www.arl.noaa.gov/ss/climate
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
</x-flowed>
Original Filename: 1197325034.txt | Return to the index page | Permalink | Later Emails
From: Tom Wigley <wigley@xxxxxxxxx.xxx>
To: santer1@xxxxxxxxx.xxx
Subject: Re: [Fwd: [Fwd: FW: Press Release from The Science & Environmental Policy Project]]
Date: Mon, 10 Dec 2007 17:17:xxx xxxx xxxx
Cc: carl mears <mears@xxxxxxxxx.xxx>, Frank Wentz <frank.wentz@xxxxxxxxx.xxx>, Tom Wigley <wigley@xxxxxxxxx.xxx>, Steven Sherwood <Steven.Sherwood@xxxxxxxxx.xxx>, John Lanzante <John.Lanzante@xxxxxxxxx.xxx>, "'Dian J. Seidel'" <dian.seidel@xxxxxxxxx.xxx>, Melissa Free <Melissa.Free@xxxxxxxxx.xxx>, Karl Taylor <taylor13@xxxxxxxxx.xxx>, Steve Klein <klein21@xxxxxxxxx.xxx>, Leopold Haimberger <leopold.haimberger@xxxxxxxxx.xxx>, "Thorne, Peter" <peter.thorne@xxxxxxxxx.xxx>, "'Philip D. Jones'" <p.jones@xxxxxxxxx.xxx>
<x-flowed>
Dear all,
I think the scientific fraud committed by Douglass needs to
be exposed. His co-authors may be innocent bystanders, but
I doubt it.
In normal circumstances, what Douglass has done would cause
him to lose his job -- a parallel is the South Korean cloning
fraud case.
I have suggested that someone like Chris Mooney should be
told about this.
Tom.
++++++++++++++++++++
Ben Santer wrote:
> Dear folks,
>
> I knew this would happen. In my opinion, we should respond to this
> continued misrepresentation of the science sooner rather than later.
>
> With best regards,
>
> Ben
> ----------------------------------------------------------------------------
>
> Benjamin D. Santer
> Program for Climate Model Diagnosis and Intercomparison
> Lawrence Livermore National Laboratory
> P.O. Box 808, Mail Stop L-103
> Livermore, CA 94550, U.S.A.
> Tel: (9xxx xxxx xxxx
> FAX: (9xxx xxxx xxxx
> email: santer1@xxxxxxxxx.xxx
> ----------------------------------------------------------------------------
>
>
> ------------------------------------------------------------------------
>
> Subject:
> [Fwd: FW: Press Release from The Science & Environmental Policy Project]
> From:
> "Thomas.R.Karl" <Thomas.R.Karl@xxxxxxxxx.xxx>
> Date:
> Mon, 10 Dec 2007 17:23:xxx xxxx xxxx
> To:
> _NESDIS NCDC CCSP Temp Trends Lead Authors
> <CCSPTempTrendAuthors.NCDC@xxxxxxxxx.xxx>
>
> To:
> _NESDIS NCDC CCSP Temp Trends Lead Authors
> <CCSPTempTrendAuthors.NCDC@xxxxxxxxx.xxx>
>
>
> FYI --- related to trop-sfc temps
>
> ------------------------------------------------------------------------
> *From:* George Marshall Institute [mailto:info@xxxxxxxxx.xxx]
> *Sent:* Monday, December 10, 2007 4:24 PM
> *To:* info@xxxxxxxxx.xxx
> *Subject:* Press Release from The Science & Environmental Policy Project
>
> */Press Release from The Science & Environmental Policy Project/**/ /*
>
> **Where & When**
>
> *The National Press Club*
>
> *529 14th Street, NW, 13th Floor*
>
> *Lisagor Room*
>
> *Washington, DC 20045*
>
> **
>
> **December 14, 2007 **
>
> **8am-11am **
>
> **
>
> *Breakfast refreshments will be served.*
>
> **
>
> **/To RSVP, please email info@xxxxxxxxx.xxx <mailto:info@xxxxxxxxx.xxx>. /**
>
> //
>
>
>
> You are invited to a timely breakfast briefing
>
> on December 14, 2007 at 8:30 a.m. at the National Press Club,
> organized by
>
> The Science & Environmental Policy Project (SEPP).
>
> As Al Gore collects his Nobel Prize and 15,000(more or less) in Bali
> struggle to find a successor regime for the ineffective and unlamented
> Kyoto Protocol, an 'inconvenient truth' has emerged:
>
> NATURE RULES THE CLIMATE: HUMAN-PRODUCED GREENHOUSE GASES ARE NOT
> RESPONSIBLE FOR GLOBAL WARMING. Therefore, schemes to control CO2
> emissions are ineffective and pointless, though very costly.
>
> Come and listen to the authors of a peer-reviewed scientific study,
> just published in the International Journal of Climatology (of the
> Royal Meteorological Society), present their startling findings.
>
> Presenters:
>
> *Prof. David Douglass*, University of Rochester: GH Models clash with
> best observations
>
> *Prof. John Christy*, University of Alabama: How GH models
> overestimate GH warming
>
> *Prof. S. Fred Singer*, University of Virginia: Changes in solar
> activity control the climate.
>
> I am sure you will appreciate the importance of their new result. Once
> one accepts the documented evidence that CO2 is insignificant in
> warming the climate, all kinds of consequences follow logically:
>
> *
Original Filename: 1197507092.txt | Return to the index page | Permalink | Later Emails
From: Ben Santer <santer1@xxxxxxxxx.xxx>
To: Tim Osborn <t.osborn@xxxxxxxxx.xxx>
Subject: Re: Douglass paper
Date: Wed, 12 Dec 2007 19:51:xxx xxxx xxxx
Reply-to: santer1@xxxxxxxxx.xxx
Cc: Phil Jones <p.jones@xxxxxxxxx.xxx>, Keith Briffa <k.briffa@xxxxxxxxx.xxx>, Tom Wigley <wigley@xxxxxxxxx.xxx>
<x-flowed>
Dear Tim,
Thanks for the "heads up". As Phil mentioned, I was already aware of
this. The Douglass et al. paper was rejected twice before it was finally
accepted by IJC. I think this paper is a real embarrassment for the IJC.
It has serious scientific flaws. I'm already working on a response.
Phil can tell you about some of the other sordid details of Douglass et
al. These guys ignored information from radiosonde datasets that did not
support their "models are wrong" argument (even though they had these
datasets in their possession). Pretty deplorable behaviour...
Douglass is the guy who famously concluded (after examining the
temperature response to Pinatubo) that the climate system has negative
sensitivity. Amazingly, he managed to publish that crap in GRL. Christy
sure does manage to pick some brilliant scientific collaborators...
With best regards,
Ben
Tim Osborn wrote:
> Hi Ben,
>
> I guess it's likely that you're aware of the Douglass paper that's just
> come out in IJC, but in case you aren't then a reprint is attached.
> They are somewhat critical of your 2005 paper, though I recall that some
> (most?) of Douglass' previous papers -- and papers that he's tried to
> get through the review process -- appear to have serious problems.
>
> cc Phil & Keith for your interest too!
>
> Cheers
>
> Tim
> 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@xxxxxxxxx.xxx
> phone: xxx xxxx xxxx
> fax: xxx xxxx xxxx
> web: http://www.cru.uea.ac.uk/~timo/
> sunclock: http://www.cru.uea.ac.uk/~timo/sunclock.htm
>
--
----------------------------------------------------------------------------
Benjamin D. Santer
Program for Climate Model Diagnosis and Intercomparison
Lawrence Livermore National Laboratory
P.O. Box 808, Mail Stop L-103
Livermore, CA 94550, U.S.A.
Tel: (9xxx xxxx xxxx
FAX: (9xxx xxxx xxxx
email: santer1@xxxxxxxxx.xxx
----------------------------------------------------------------------------
</x-flowed>
Original Filename: 1197590292.txt | Return to the index page | Permalink | Later Emails
From: Ben Santer <santer1@xxxxxxxxx.xxx>
To: carl mears <mears@xxxxxxxxx.xxx>
Subject: Re: [Fwd: sorry to take your time up, but really do need a scrub of this singer/christy/etc effort]
Date: Thu, 13 Dec 2007 18:58:xxx xxxx xxxx
Reply-to: santer1@xxxxxxxxx.xxx
Cc: SHERWOOD Steven <steven.sherwood@xxxxxxxxx.xxx>, Tom Wigley <wigley@xxxxxxxxx.xxx>, Frank Wentz <frank.wentz@xxxxxxxxx.xxx>, "'Philip D. Jones'" <p.jones@xxxxxxxxx.xxx>, Karl Taylor <taylor13@xxxxxxxxx.xxx>, Steve Klein <klein21@xxxxxxxxx.xxx>, John Lanzante <John.Lanzante@xxxxxxxxx.xxx>, "Thorne, Peter" <peter.thorne@xxxxxxxxx.xxx>, "'Dian J. Seidel'" <dian.seidel@xxxxxxxxx.xxx>, Melissa Free <Melissa.Free@xxxxxxxxx.xxx>, Leopold Haimberger <leopold.haimberger@xxxxxxxxx.xxx>, "'Francis W. Zwiers'" <francis.zwiers@xxxxxxxxx.xxx>, "Michael C. MacCracken" <mmaccrac@xxxxxxxxx.xxx>, Thomas R Karl <Thomas.R.Karl@xxxxxxxxx.xxx>, Tim Osborn <t.osborn@xxxxxxxxx.xxx>, "David C. Bader" <bader2@xxxxxxxxx.xxx>, 'Susan Solomon' <ssolomon@xxxxxxxxx.xxx>
<x-flowed>
Dear folks,
I've been doing some calculations to address one of the statistical
issues raised by the Douglass et al. paper in the International Journal
of Climatology. Here are some of my results.
Recall that Douglass et al. calculated synthetic T2LT and T2
temperatures from the CMIP-3 archive of 20th century simulations
("20c3m" runs). They used a total of 67 20c3m realizations, performed
with 22 different models. In calculating the statistical uncertainty of
the model trends, they introduced sigma{SE}, an "estimate of the
uncertainty of the mean of the predictions of the trends". They defined
sigma{SE} as follows:
sigma{SE} = sigma / sqrt(N - 1), where
"N = 22 is the number of independent models".
As we've discussed in our previous correspondence, this definition has
serious problems (see comments from Carl and Steve below), and allows
Douglass et al. to reach the erroneous conclusion that modeled T2LT and
T2 trends are significantly different from the observed T2LT and T2
trends in both the RSS and UAH datasets. This comparison of simulated
and observed T2LT and T2 trends is given in Table III of Douglass et al.
[As an amusing aside, I note that the RSS datasets are referred to as
"RSS" in this table, while UAH results are designated as "MSU". I guess
there's only one true "MSU" dataset...]
I decided to take a quick look at the issue of the statistical
significance of differences between simulated and observed tropospheric
temperature trends. My first cut at this "quick look" involves only UAH
and RSS observational data - I have not yet done any tests with
radiosonde datas, UMD T2 data, or satellite results from Zou et al.
I operated on the same 49 realizations of the 20c3m experiment that we
used in Chapter 5 of CCSP 1.1. As in our previous work, all model
results are synthetic T2LT and T2 temperatures that I calculated using a
static weighting function approach. I have not yet implemented Carl's
more sophisticated method of estimating synthetic MSU temperatures from
model data (which accounts for effects of topography and land/ocean
differences). However, for the current application, the simple static
weighting function approach is more than adequate, since we are focusing
on T2LT and T2 changes over tropical oceans only - so topographic and
land-ocean differences are unimportant. Note that I still need to
calculate synthetic MSU temperatures from about xxx xxxx xxxxc3m realizations
which were not in the CMIP-3 database at the time we were working on the
CCSP report. For the full response to Douglass et al., we should use the
same 67 20c3m realizations that they employed.
For each of the 49 realizations that I processed, I first masked out all
tropical land areas, and then calculated the spatial averages of
monthly-mean, gridded T2LT and T2 data over tropical oceans (20N-20S).
All model and observational results are for the common 252-month period
from January 1979 to December 1999 - the longest period of overlap
between the RSS and UAH MSU data and the bulk of the 20c3m runs. The
simulated trends given by Douglass et al. are calculated over the same
1979 to 1999 period; however, they use a longer period (1979 to 2004)
for calculating observational trends - so there is an inconsistency
between their model and observational analysis periods, which they do
not explain. This difference in analysis periods is a little puzzling
given that we are dealing with relatively short observational record
lengths, resulting in some sensitivity to end-point effects.
I then calculated anomalies of the spatially-averaged T2LT and T2 data
(w.r.t. climatological monthly-means over 1xxx xxxx xxxx), and fit
least-squares linear trends to model and observational time series. The
standard errors of the trends were adjusted for temporal autocorrelation
of the regression residuals, as described in Santer et al. (2000)
["Statistical significance of trends and trend differences in
layer-average atmospheric temperature time series"; JGR 105, 7xxx xxxx xxxx.]
Consider first panel A of the attached plot. This shows the simulated
and observed T2LT trends over 1979 to 1999 (again, over 20N-20S, oceans
only) with their adjusted 1-sigma confidence intervals). For the UAH and
RSS data, it was possible to check against the adjusted confidence
intervals independently calculated by Dian during the course of work on
the CCSP report. Our adjusted confidence intervals are in good
agreement. The grey shaded envelope in panel A denotes the 1-sigma
standard error for the RSS T2LT trend.
There are 49 pairs of UAH-minus-model trend differences and 49 pairs of
RSS-minus-model trend differences. We can therefore test - for each
model and each 20c3m realization - whether there is a statistically
significant difference between the observed and simulated trends.
Let bx and by represent any single pair of modeled and observed trends,
with adjusted standard errors s{bx} and s{by}. As in our previous work
(and as in related work by John Lanzante), we define the normalized
trend difference d as:
d = (bx - by) / sqrt[ (s{bx})**2 + (s{by})**2 ]
Under the assumption that d is normally distributed, values of d > +1.96
or < -1.96 indicate observed-minus-model trend differences that are
significant at the 5% level. We are performing a two-tailed test here,
since we have no information a priori about the "direction" of the model
trend (i.e., whether we expect the simulated trend to be significantly
larger or smaller than observed).
Panel c shows values of the normalized trend difference for T2LT trends.
the grey shaded area spans the range +1.96 to -1.96, and identifies the
region where we fail to reject the null hypothesis (H0) of no
significant difference between observed and simulated trends.
Consider the solid symbols first, which give results for tests involving
RSS data. We would reject H0 in only one out of 49 cases (for the
CCCma-CGCM3.1(T47) model). The open symbols indicate results for tests
involving UAH data. Somewhat surprisingly, we get the same qualitative
outcome that we obtained for tests involving RSS data: only one of the
UAH-model trend pairs yields a difference that is statistically
significant at the 5% level.
Panels b and d provide results for T2 trends. Results are very similar
to those achieved with T2LT trends. Irrespective of whether RSS or UAH
T2 data are used, significant trend differences occur in only one of 49
cases.
Bottom line: Douglass et al. claim that "In all cases UAH and RSS
satellite trends are inconsistent with model trends." (page 6, lines
61-62). This claim is categorically wrong. In fact, based on our
results, one could justifiably claim that THERE IS ONLY ONE CASE in
which model T2LT and T2 trends are inconsistent with UAH and RSS
results! These guys screwed up big time.
SENSITIVITY TESTS
QUESTION 1: Some of the model-data trend comparisons made by Douglass et
al. used temperatures averaged over 30N-30S rather than 20N-20S. What
happens if we repeat our simple trend significance analysis using T2LT
and T2 data averaged over ocean areas between 30N-30S?
ANSWER 1: Very little. The results described above for oceans areas
between 20N-20S are virtually unchanged.
QUESTION 2: Even though it's clearly inappropriate to estimate the
standard errors of the linear trends WITHOUT accounting for temporal
autocorrelation effects (the 252 time sample are clearly not
independent; effective sample sizes typically range from 6 to 56),
someone is bound to ask what the outcome is when one repeats the paired
trend tests with non-adjusted standard errors. So here are the results:
T2LT tests, RSS observational data: 19 out of 49 trend differences are
significant at the 5% level.
T2LT tests, UAH observational data: 34 out of 49 trend differences are
significant at the 5% level.
T2 tests, RSS observational data: 16 out of 49 trend differences are
significant at the 5% level.
T2 tests, UAH observational data: 35 out of 49 trend differences are
significant at the 5% level.
So even under the naive (and incorrect) assumption that each model and
observational time series contains 252 independent time samples, we
STILL find no support for Douglass et al.'s assertion that: "In all
cases UAH and RSS satellite trends are inconsistent with model trends."
Q.E.D.
If Leo is agreeable, I'm hopeful that we'll be able to perform a similar
trend comparison using synthetic MSU T2LT and T2 temperatures calculated
from the RAOBCORE radiosonde data - all versions, not just v1.2!
As you can see from the email list, I've expanded our "focus group" a
little bit, since a number of you have written to me about this issue.
I am leaving for Miami on Monday, Dec. 17th. My Mom is having cataract
surgery, and I'd like to be around to provide her with moral and
practical support. I'm not exactly sure when I'll be returning to PCMDI
- although I hope I won't be gone longer than a week. As soon as I get
back, I'll try to make some more progress with this stuff. Any
suggestions or comments on what I've done so far would be greatly
appreciated. And for the time being, I think we should not alert
Douglass et al. to our results.
With best regards, and happy holidays! May all your "Singers" be carol
singers, and not of the S. Fred variety...
Ben
(P.S.: I noticed one unfortunate typo in Table II of Douglass et al. The
MIROC3.2 (medres) model is referred to as "MIROC3.2_Merdes"....)
carl mears wrote:
> Hi Steve
>
> I'd say it's the equivalent of rolling a 6-sided die a hundred times, and
> finding a mean value of ~3.5 and a standard deviation of ~1.7, and
> calculating the standard error of the mean to be ~0.17 (so far so
> good). An then rolling the die one more time, getting a 2, and
> claiming that the die is no longer 6 sided because the new measurement
> is more than 2 standard errors from the mean.
>
> In my view, this problem trumps the other problems in the paper.
> I can't believe Douglas is a fellow of the American Physical Society.
>
> -Carl
>
>
> At 02:07 AM 12/6/2007, you wrote:
>> If I understand correctly, what Douglass et al. did makes the stronger
>> assumption that unforced variability is *insignificant*. Their
>> statistical test is logically equivalent to falsifying a climate model
>> because it did not consistently predict a particular storm on a
>> particular day two years from now.
>
>
> Dr. Carl Mears
> Remote Sensing Systems
> 438 First Street, Suite 200, Santa Rosa, CA 95401
> mears@xxxxxxxxx.xxx
> xxx xxxx xxxxx21
> xxx xxxx xxxx(fax))
--
----------------------------------------------------------------------------
Benjamin D. Santer
Program for Climate Model Diagnosis and Intercomparison
Lawrence Livermore National Laboratory
P.O. Box 808, Mail Stop L-103
Livermore, CA 94550, U.S.A.
Tel: (9xxx xxxx xxxx
FAX: (9xxx xxxx xxxx
email: santer1@xxxxxxxxx.xxx
----------------------------------------------------------------------------
</x-flowed>
Attachment Converted: "c:eudoraattachdouglass_reply1.pdf"
Original Filename: 1197590293.txt | Return to the index page | Permalink | Later Emails
From: Ben Santer <santer1@xxxxxxxxx.xxx>
To: carl mears <mears@xxxxxxxxx.xxx>
Subject: Re: [Fwd: sorry to take your time up, but really do need a scrub of this singer/christy/etc effort]
Date: Thu, 13 Dec 2007 18:58:xxx xxxx xxxx
Reply-to: santer1@xxxxxxxxx.xxx
Cc: SHERWOOD Steven <steven.sherwood@xxxxxxxxx.xxx>, Tom Wigley <wigley@xxxxxxxxx.xxx>, Frank Wentz <frank.wentz@xxxxxxxxx.xxx>, "'Philip D. Jones'" <p.jones@xxxxxxxxx.xxx>, Karl Taylor <taylor13@xxxxxxxxx.xxx>, Steve Klein <klein21@xxxxxxxxx.xxx>, John Lanzante <John.Lanzante@xxxxxxxxx.xxx>, "Thorne, Peter" <peter.thorne@xxxxxxxxx.xxx>, "'Dian J. Seidel'" <dian.seidel@xxxxxxxxx.xxx>, Melissa Free <Melissa.Free@xxxxxxxxx.xxx>, Leopold Haimberger <leopold.haimberger@xxxxxxxxx.xxx>, "'Francis W. Zwiers'" <francis.zwiers@xxxxxxxxx.xxx>, "Michael C. MacCracken" <mmaccrac@xxxxxxxxx.xxx>, Thomas R Karl <Thomas.R.Karl@xxxxxxxxx.xxx>, Tim Osborn <t.osborn@xxxxxxxxx.xxx>, "David C. Bader" <bader2@xxxxxxxxx.xxx>, 'Susan Solomon' <ssolomon@xxxxxxxxx.xxx>
<x-flowed>
Dear folks,
I've been doing some calculations to address one of the statistical
issues raised by the Douglass et al. paper in the International Journal
of Climatology. Here are some of my results.
Recall that Douglass et al. calculated synthetic T2LT and T2
temperatures from the CMIP-3 archive of 20th century simulations
("20c3m" runs). They used a total of 67 20c3m realizations, performed
with 22 different models. In calculating the statistical uncertainty of
the model trends, they introduced sigma{SE}, an "estimate of the
uncertainty of the mean of the predictions of the trends". They defined
sigma{SE} as follows:
sigma{SE} = sigma / sqrt(N - 1), where
"N = 22 is the number of independent models".
As we've discussed in our previous correspondence, this definition has
serious problems (see comments from Carl and Steve below), and allows
Douglass et al. to reach the erroneous conclusion that modeled T2LT and
T2 trends are significantly different from the observed T2LT and T2
trends in both the RSS and UAH datasets. This comparison of simulated
and observed T2LT and T2 trends is given in Table III of Douglass et al.
[As an amusing aside, I note that the RSS datasets are referred to as
"RSS" in this table, while UAH results are designated as "MSU". I guess
there's only one true "MSU" dataset...]
I decided to take a quick look at the issue of the statistical
significance of differences between simulated and observed tropospheric
temperature trends. My first cut at this "quick look" involves only UAH
and RSS observational data - I have not yet done any tests with
radiosonde datas, UMD T2 data, or satellite results from Zou et al.
I operated on the same 49 realizations of the 20c3m experiment that we
used in Chapter 5 of CCSP 1.1. As in our previous work, all model
results are synthetic T2LT and T2 temperatures that I calculated using a
static weighting function approach. I have not yet implemented Carl's
more sophisticated method of estimating synthetic MSU temperatures from
model data (which accounts for effects of topography and land/ocean
differences). However, for the current application, the simple static
weighting function approach is more than adequate, since we are focusing
on T2LT and T2 changes over tropical oceans only - so topographic and
land-ocean differences are unimportant. Note that I still need to
calculate synthetic MSU temperatures from about xxx xxxx xxxxc3m realizations
which were not in the CMIP-3 database at the time we were working on the
CCSP report. For the full response to Douglass et al., we should use the
same 67 20c3m realizations that they employed.
For each of the 49 realizations that I processed, I first masked out all
tropical land areas, and then calculated the spatial averages of
monthly-mean, gridded T2LT and T2 data over tropical oceans (20N-20S).
All model and observational results are for the common 252-month period
from January 1979 to December 1999 - the longest period of overlap
between the RSS and UAH MSU data and the bulk of the 20c3m runs. The
simulated trends given by Douglass et al. are calculated over the same
1979 to 1999 period; however, they use a longer period (1979 to 2004)
for calculating observational trends - so there is an inconsistency
between their model and observational analysis periods, which they do
not explain. This difference in analysis periods is a little puzzling
given that we are dealing with relatively short observational record
lengths, resulting in some sensitivity to end-point effects.
I then calculated anomalies of the spatially-averaged T2LT and T2 data
(w.r.t. climatological monthly-means over 1xxx xxxx xxxx), and fit
least-squares linear trends to model and observational time series. The
standard errors of the trends were adjusted for temporal autocorrelation
of the regression residuals, as described in Santer et al. (2000)
["Statistical significance of trends and trend differences in
layer-average atmospheric temperature time series"; JGR 105, 7xxx xxxx xxxx.]
Consider first panel A of the attached plot. This shows the simulated
and observed T2LT trends over 1979 to 1999 (again, over 20N-20S, oceans
only) with their adjusted 1-sigma confidence intervals). For the UAH and
RSS data, it was possible to check against the adjusted confidence
intervals independently calculated by Dian during the course of work on
the CCSP report. Our adjusted confidence intervals are in good
agreement. The grey shaded envelope in panel A denotes the 1-sigma
standard error for the RSS T2LT trend.
There are 49 pairs of UAH-minus-model trend differences and 49 pairs of
RSS-minus-model trend differences. We can therefore test - for each
model and each 20c3m realization - whether there is a statistically
significant difference between the observed and simulated trends.
Let bx and by represent any single pair of modeled and observed trends,
with adjusted standard errors s{bx} and s{by}. As in our previous work
(and as in related work by John Lanzante), we define the normalized
trend difference d as:
d = (bx - by) / sqrt[ (s{bx})**2 + (s{by})**2 ]
Under the assumption that d is normally distributed, values of d > +1.96
or < -1.96 indicate observed-minus-model trend differences that are
significant at the 5% level. We are performing a two-tailed test here,
since we have no information a priori about the "direction" of the model
trend (i.e., whether we expect the simulated trend to be significantly
larger or smaller than observed).
Panel c shows values of the normalized trend difference for T2LT trends.
the grey shaded area spans the range +1.96 to -1.96, and identifies the
region where we fail to reject the null hypothesis (H0) of no
significant difference between observed and simulated trends.
Consider the solid symbols first, which give results for tests involving
RSS data. We would reject H0 in only one out of 49 cases (for the
CCCma-CGCM3.1(T47) model). The open symbols indicate results for tests
involving UAH data. Somewhat surprisingly, we get the same qualitative
outcome that we obtained for tests involving RSS data: only one of the
UAH-model trend pairs yields a difference that is statistically
significant at the 5% level.
Panels b and d provide results for T2 trends. Results are very similar
to those achieved with T2LT trends. Irrespective of whether RSS or UAH
T2 data are used, significant trend differences occur in only one of 49
cases.
Bottom line: Douglass et al. claim that "In all cases UAH and RSS
satellite trends are inconsistent with model trends." (page 6, lines
61-62). This claim is categorically wrong. In fact, based on our
results, one could justifiably claim that THERE IS ONLY ONE CASE in
which model T2LT and T2 trends are inconsistent with UAH and RSS
results! These guys screwed up big time.
SENSITIVITY TESTS
QUESTION 1: Some of the model-data trend comparisons made by Douglass et
al. used temperatures averaged over 30N-30S rather than 20N-20S. What
happens if we repeat our simple trend significance analysis using T2LT
and T2 data averaged over ocean areas between 30N-30S?
ANSWER 1: Very little. The results described above for oceans areas
between 20N-20S are virtually unchanged.
QUESTION 2: Even though it's clearly inappropriate to estimate the
standard errors of the linear trends WITHOUT accounting for temporal
autocorrelation effects (the 252 time sample are clearly not
independent; effective sample sizes typically range from 6 to 56),
someone is bound to ask what the outcome is when one repeats the paired
trend tests with non-adjusted standard errors. So here are the results:
T2LT tests, RSS observational data: 19 out of 49 trend differences are
significant at the 5% level.
T2LT tests, UAH observational data: 34 out of 49 trend differences are
significant at the 5% level.
T2 tests, RSS observational data: 16 out of 49 trend differences are
significant at the 5% level.
T2 tests, UAH observational data: 35 out of 49 trend differences are
significant at the 5% level.
So even under the naive (and incorrect) assumption that each model and
observational time series contains 252 independent time samples, we
STILL find no support for Douglass et al.'s assertion that: "In all
cases UAH and RSS satellite trends are inconsistent with model trends."
Q.E.D.
If Leo is agreeable, I'm hopeful that we'll be able to perform a similar
trend comparison using synthetic MSU T2LT and T2 temperatures calculated
from the RAOBCORE radiosonde data - all versions, not just v1.2!
As you can see from the email list, I've expanded our "focus group" a
little bit, since a number of you have written to me about this issue.
I am leaving for Miami on Monday, Dec. 17th. My Mom is having cataract
surgery, and I'd like to be around to provide her with moral and
practical support. I'm not exactly sure when I'll be returning to PCMDI
- although I hope I won't be gone longer than a week. As soon as I get
back, I'll try to make some more progress with this stuff. Any
suggestions or comments on what I've done so far would be greatly
appreciated. And for the time being, I think we should not alert
Douglass et al. to our results.
With best regards, and happy holidays! May all your "Singers" be carol
singers, and not of the S. Fred variety...
Ben
(P.S.: I noticed one unfortunate typo in Table II of Douglass et al. The
MIROC3.2 (medres) model is referred to as "MIROC3.2_Merdes"....)
carl mears wrote:
> Hi Steve
>
> I'd say it's the equivalent of rolling a 6-sided die a hundred times, and
> finding a mean value of ~3.5 and a standard deviation of ~1.7, and
> calculating the standard error of the mean to be ~0.17 (so far so
> good). An then rolling the die one more time, getting a 2, and
> claiming that the die is no longer 6 sided because the new measurement
> is more than 2 standard errors from the mean.
>
> In my view, this problem trumps the other problems in the paper.
> I can't believe Douglas is a fellow of the American Physical Society.
>
> -Carl
>
>
> At 02:07 AM 12/6/2007, you wrote:
>> If I understand correctly, what Douglass et al. did makes the stronger
>> assumption that unforced variability is *insignificant*. Their
>> statistical test is logically equivalent to falsifying a climate model
>> because it did not consistently predict a particular storm on a
>> particular day two years from now.
>
>
> Dr. Carl Mears
> Remote Sensing Systems
> 438 First Street, Suite 200, Santa Rosa, CA 95401
> mears@xxxxxxxxx.xxx
> xxx xxxx xxxxx21
> xxx xxxx xxxx(fax))
--
----------------------------------------------------------------------------
Benjamin D. Santer
Program for Climate Model Diagnosis and Intercomparison
Lawrence Livermore National Laboratory
P.O. Box 808, Mail Stop L-103
Livermore, CA 94550, U.S.A.
Tel: (9xxx xxxx xxxx
FAX: (9xxx xxxx xxxx
email: santer1@xxxxxxxxx.xxx
----------------------------------------------------------------------------
</x-flowed>
Attachment Converted: "c:documents and settingstim osbornmy documentseudoraattachdouglass_reply1.pdf"
Original Filename: 1197660675.txt | Return to the index page | Permalink | Later Emails
From: Ben Santer <santer1@xxxxxxxxx.xxx>
To: "Thomas.R.Karl" <Thomas.R.Karl@xxxxxxxxx.xxx>
Subject: Re: [Fwd: sorry to take your time up, but really do need a scrub of this singer/christy/etc effort]
Date: Fri, 14 Dec 2007 14:31:xxx xxxx xxxx
Reply-to: santer1@xxxxxxxxx.xxx
Cc: carl mears <mears@xxxxxxxxx.xxx>, SHERWOOD Steven <steven.sherwood@xxxxxxxxx.xxx>, Tom Wigley <wigley@xxxxxxxxx.xxx>, Frank Wentz <frank.wentz@xxxxxxxxx.xxx>, "'Philip D. Jones'" <p.jones@xxxxxxxxx.xxx>, Karl Taylor <taylor13@xxxxxxxxx.xxx>, Steve Klein <klein21@xxxxxxxxx.xxx>, John Lanzante <John.Lanzante@xxxxxxxxx.xxx>, "Thorne, Peter" <peter.thorne@xxxxxxxxx.xxx>, "'Dian J. Seidel'" <dian.seidel@xxxxxxxxx.xxx>, Melissa Free <Melissa.Free@xxxxxxxxx.xxx>, Leopold Haimberger <leopold.haimberger@xxxxxxxxx.xxx>, "'Francis W. Zwiers'" <francis.zwiers@xxxxxxxxx.xxx>, "Michael C. MacCracken" <mmaccrac@xxxxxxxxx.xxx>, Tim Osborn <t.osborn@xxxxxxxxx.xxx>, "David C. Bader" <bader2@xxxxxxxxx.xxx>, 'Susan Solomon' <ssolomon@xxxxxxxxx.xxx>
<x-flowed>
Dear Tom,
As promised, I've now repeated all of the significance testing involving
model-versus-observed trend differences, but this time using
spatially-averaged T2 and T2LT changes that are not "masked out" over
tropical land areas. As I mentioned this morning, the use of non-masked
data facilitates a direct comparison with Douglass et al.
The results for combined changes over tropical land and ocean are very
similar to those I sent out yesterday, which were for T2 and T2LT
changes over tropical oceans only:
COMBINED LAND/OCEAN RESULTS (WITH STANDARD ERRORS ADJUSTED FOR TEMPORAL
AUTOCORRELATION EFFECTS; SPATIAL AVERAGES OVER 20N-20S; ANALYSIS PERIOD
1979 TO 1999)
T2LT tests, RSS observational data: 0 out of 49 model-versus-observed
trend differences are significant at the 5% level.
T2LT tests, UAH observational data: 1 out of 49 model-versus-observed
trend differences are significant at the 5% level.
T2 tests, RSS observational data: 1 out of 49 model-versus-observed
trend differences are significant at the 5% level.
T2 tests, UAH observational data: 1 out of 49 model-versus-observed
trend differences are significant at the 5% level.
So our conclusion - that model tropical T2 and T2LT trends are, in
virtually all realizations and models, not significantly different from
either RSS or UAH trends - is not sensitive to whether we do the
significance testing with "ocean only" or combined "land+ocean"
temperature changes.
With best regards, and happy holidays to all!
Ben
Thomas.R.Karl wrote:
> Ben,
>
> This is very informative. One question I raise is whether the results
> would have been at all different if you had not masked the land. I
> doubt it, but it would be nice to know.
>
> Tom
>
> Ben Santer said the following on 12/13/2007 9:58 PM:
>> Dear folks,
>>
>> I've been doing some calculations to address one of the statistical
>> issues raised by the Douglass et al. paper in the International
>> Journal of Climatology. Here are some of my results.
>>
>> Recall that Douglass et al. calculated synthetic T2LT and T2
>> temperatures from the CMIP-3 archive of 20th century simulations
>> ("20c3m" runs). They used a total of 67 20c3m realizations, performed
>> with 22 different models. In calculating the statistical uncertainty
>> of the model trends, they introduced sigma{SE}, an "estimate of the
>> uncertainty of the mean of the predictions of the trends". They defined
>> sigma{SE} as follows:
>>
>> sigma{SE} = sigma / sqrt(N - 1), where
>>
>> "N = 22 is the number of independent models".
>>
>> As we've discussed in our previous correspondence, this definition has
>> serious problems (see comments from Carl and Steve below), and allows
>> Douglass et al. to reach the erroneous conclusion that modeled T2LT
>> and T2 trends are significantly different from the observed T2LT and
>> T2 trends in both the RSS and UAH datasets. This comparison of
>> simulated and observed T2LT and T2 trends is given in Table III of
>> Douglass et al.
>> [As an amusing aside, I note that the RSS datasets are referred to as
>> "RSS" in this table, while UAH results are designated as "MSU". I
>> guess there's only one true "MSU" dataset...]
>>
>> I decided to take a quick look at the issue of the statistical
>> significance of differences between simulated and observed
>> tropospheric temperature trends. My first cut at this "quick look"
>> involves only UAH and RSS observational data - I have not yet done any
>> tests with radiosonde datas, UMD T2 data, or satellite results from
>> Zou et al.
>>
>> I operated on the same 49 realizations of the 20c3m experiment that we
>> used in Chapter 5 of CCSP 1.1. As in our previous work, all model
>> results are synthetic T2LT and T2 temperatures that I calculated using
>> a static weighting function approach. I have not yet implemented
>> Carl's more sophisticated method of estimating synthetic MSU
>> temperatures from model data (which accounts for effects of topography
>> and land/ocean differences). However, for the current application, the
>> simple static weighting function approach is more than adequate, since
>> we are focusing on T2LT and T2 changes over tropical oceans only - so
>> topographic and land-ocean differences are unimportant. Note that I
>> still need to calculate synthetic MSU temperatures from about xxx xxxx xxxx
>> 20c3m realizations which were not in the CMIP-3 database at the time
>> we were working on the CCSP report. For the full response to Douglass
>> et al., we should use the same 67 20c3m realizations that they employed.
>>
>> For each of the 49 realizations that I processed, I first masked out
>> all tropical land areas, and then calculated the spatial averages of
>> monthly-mean, gridded T2LT and T2 data over tropical oceans (20N-20S).
>> All model and observational results are for the common 252-month
>> period from January 1979 to December 1999 - the longest period of
>> overlap between the RSS and UAH MSU data and the bulk of the 20c3m
>> runs. The simulated trends given by Douglass et al. are calculated
>> over the same 1979 to 1999 period; however, they use a longer period
>> (1979 to 2004) for calculating observational trends - so there is an
>> inconsistency between their model and observational analysis periods,
>> which they do not explain. This difference in analysis periods is a
>> little puzzling given that we are dealing with relatively short
>> observational record lengths, resulting in some sensitivity to
>> end-point effects.
>>
>> I then calculated anomalies of the spatially-averaged T2LT and T2 data
>> (w.r.t. climatological monthly-means over 1xxx xxxx xxxx), and fit
>> least-squares linear trends to model and observational time series.
>> The standard errors of the trends were adjusted for temporal
>> autocorrelation of the regression residuals, as described in Santer et
>> al. (2000) ["Statistical significance of trends and trend differences
>> in layer-average atmospheric temperature time series"; JGR 105,
>> 7xxx xxxx xxxx.]
>>
>> Consider first panel A of the attached plot. This shows the simulated
>> and observed T2LT trends over 1979 to 1999 (again, over 20N-20S,
>> oceans only) with their adjusted 1-sigma confidence intervals). For
>> the UAH and RSS data, it was possible to check against the adjusted
>> confidence intervals independently calculated by Dian during the
>> course of work on the CCSP report. Our adjusted confidence intervals
>> are in good agreement. The grey shaded envelope in panel A denotes the
>> 1-sigma standard error for the RSS T2LT trend.
>>
>> There are 49 pairs of UAH-minus-model trend differences and 49 pairs
>> of RSS-minus-model trend differences. We can therefore test - for each
>> model and each 20c3m realization - whether there is a statistically
>> significant difference between the observed and simulated trends.
>>
>> Let bx and by represent any single pair of modeled and observed
>> trends, with adjusted standard errors s{bx} and s{by}. As in our
>> previous work (and as in related work by John Lanzante), we define the
>> normalized trend difference d as:
>>
>> d = (bx - by) / sqrt[ (s{bx})**2 + (s{by})**2 ]
>>
>> Under the assumption that d is normally distributed, values of d >
>> +1.96 or < -1.96 indicate observed-minus-model trend differences that
>> are significant at the 5% level. We are performing a two-tailed test
>> here, since we have no information a priori about the "direction" of
>> the model trend (i.e., whether we expect the simulated trend to be
>> significantly larger or smaller than observed).
>>
>> Panel c shows values of the normalized trend difference for T2LT trends.
>> the grey shaded area spans the range +1.96 to -1.96, and identifies
>> the region where we fail to reject the null hypothesis (H0) of no
>> significant difference between observed and simulated trends.
>>
>> Consider the solid symbols first, which give results for tests
>> involving RSS data. We would reject H0 in only one out of 49 cases
>> (for the CCCma-CGCM3.1(T47) model). The open symbols indicate results
>> for tests involving UAH data. Somewhat surprisingly, we get the same
>> qualitative outcome that we obtained for tests involving RSS data:
>> only one of the UAH-model trend pairs yields a difference that is
>> statistically significant at the 5% level.
>>
>> Panels b and d provide results for T2 trends. Results are very similar
>> to those achieved with T2LT trends. Irrespective of whether RSS or UAH
>> T2 data are used, significant trend differences occur in only one of
>> 49 cases.
>>
>> Bottom line: Douglass et al. claim that "In all cases UAH and RSS
>> satellite trends are inconsistent with model trends." (page 6, lines
>> 61-62). This claim is categorically wrong. In fact, based on our
>> results, one could justifiably claim that THERE IS ONLY ONE CASE in
>> which model T2LT and T2 trends are inconsistent with UAH and RSS
>> results! These guys screwed up big time.
>>
>> SENSITIVITY TESTS
>>
>> QUESTION 1: Some of the model-data trend comparisons made by Douglass
>> et al. used temperatures averaged over 30N-30S rather than 20N-20S.
>> What happens if we repeat our simple trend significance analysis using
>> T2LT and T2 data averaged over ocean areas between 30N-30S?
>>
>> ANSWER 1: Very little. The results described above for oceans areas
>> between 20N-20S are virtually unchanged.
>>
>> QUESTION 2: Even though it's clearly inappropriate to estimate the
>> standard errors of the linear trends WITHOUT accounting for temporal
>> autocorrelation effects (the 252 time sample are clearly not
>> independent; effective sample sizes typically range from 6 to 56),
>> someone is bound to ask what the outcome is when one repeats the
>> paired trend tests with non-adjusted standard errors. So here are the
>> results:
>>
>> T2LT tests, RSS observational data: 19 out of 49 trend differences are
>> significant at the 5% level.
>> T2LT tests, UAH observational data: 34 out of 49 trend differences are
>> significant at the 5% level.
>>
>> T2 tests, RSS observational data: 16 out of 49 trend differences are
>> significant at the 5% level.
>> T2 tests, UAH observational data: 35 out of 49 trend differences are
>> significant at the 5% level.
>>
>> So even under the naive (and incorrect) assumption that each model and
>> observational time series contains 252 independent time samples, we
>> STILL find no support for Douglass et al.'s assertion that: "In all
>> cases UAH and RSS satellite trends are inconsistent with model trends."
>> Q.E.D.
>>
>> If Leo is agreeable, I'm hopeful that we'll be able to perform a
>> similar trend comparison using synthetic MSU T2LT and T2 temperatures
>> calculated from the RAOBCORE radiosonde data - all versions, not just
>> v1.2!
>>
>> As you can see from the email list, I've expanded our "focus group" a
>> little bit, since a number of you have written to me about this issue.
>>
>> I am leaving for Miami on Monday, Dec. 17th. My Mom is having cataract
>> surgery, and I'd like to be around to provide her with moral and
>> practical support. I'm not exactly sure when I'll be returning to
>> PCMDI - although I hope I won't be gone longer than a week. As soon as
>> I get back, I'll try to make some more progress with this stuff. Any
>> suggestions or comments on what I've done so far would be greatly
>> appreciated. And for the time being, I think we should not alert
>> Douglass et al. to our results.
>>
>> With best regards, and happy holidays! May all your "Singers" be carol
>> singers, and not of the S. Fred variety...
>>
>> Ben
>>
>> (P.S.: I noticed one unfortunate typo in Table II of Douglass et al.
>> The MIROC3.2 (medres) model is referred to as "MIROC3.2_Merdes"....)
>>
>> carl mears wrote:
>>> Hi Steve
>>>
>>> I'd say it's the equivalent of rolling a 6-sided die a hundred times,
>>> and
>>> finding a mean value of ~3.5 and a standard deviation of ~1.7, and
>>> calculating the standard error of the mean to be ~0.17 (so far so
>>> good). An then rolling the die one more time, getting a 2, and
>>> claiming that the die is no longer 6 sided because the new measurement
>>> is more than 2 standard errors from the mean.
>>>
>>> In my view, this problem trumps the other problems in the paper.
>>> I can't believe Douglas is a fellow of the American Physical Society.
>>>
>>> -Carl
>>>
>>>
>>> At 02:07 AM 12/6/2007, you wrote:
>>>> If I understand correctly, what Douglass et al. did makes the
>>>> stronger assumption that unforced variability is *insignificant*.
>>>> Their statistical test is logically equivalent to falsifying a
>>>> climate model because it did not consistently predict a particular
>>>> storm on a particular day two years from now.
>>>
>>>
>>> Dr. Carl Mears
>>> Remote Sensing Systems
>>> 438 First Street, Suite 200, Santa Rosa, CA 95401
>>> mears@xxxxxxxxx.xxx
>>> xxx xxxx xxxxx21
>>> xxx xxxx xxxx(fax))
>>
>>
>
> --
>
> *Dr. Thomas R. Karl, L.H.D.*
>
> */Director/*//
>
> NOAA
Original Filename: 1197739308.txt | Return to the index page | Permalink | Later Emails
From: "Thomas.R.Karl" <Thomas.R.Karl@xxxxxxxxx.xxx>
To: santer1@xxxxxxxxx.xxx
Subject: Re: [Fwd: sorry to take your time up, but really do need a scrub of this singer/christy/etc effort]
Date: Sat, 15 Dec 2007 12:21:xxx xxxx xxxx
Cc: carl mears <mears@xxxxxxxxx.xxx>, SHERWOOD Steven <steven.sherwood@xxxxxxxxx.xxx>, Tom Wigley <wigley@xxxxxxxxx.xxx>, Frank Wentz <frank.wentz@xxxxxxxxx.xxx>, "'Philip D. Jones'" <p.jones@xxxxxxxxx.xxx>, Karl Taylor <taylor13@xxxxxxxxx.xxx>, Steve Klein <klein21@xxxxxxxxx.xxx>, John Lanzante <John.Lanzante@xxxxxxxxx.xxx>, "Thorne, Peter" <peter.thorne@xxxxxxxxx.xxx>, "'Dian J. Seidel'" <dian.seidel@xxxxxxxxx.xxx>, Melissa Free <Melissa.Free@xxxxxxxxx.xxx>, Leopold Haimberger <leopold.haimberger@xxxxxxxxx.xxx>, "'Francis W. Zwiers'" <francis.zwiers@xxxxxxxxx.xxx>, "Michael C. MacCracken" <mmaccrac@xxxxxxxxx.xxx>, Tim Osborn <t.osborn@xxxxxxxxx.xxx>, "David C. Bader" <bader2@xxxxxxxxx.xxx>, 'Susan Solomon' <ssolomon@xxxxxxxxx.xxx>
Thanks Ben,
You have the makings of a nice article.
I note that we would expect to 10 cases that are significantly different by chance (based
on the 196 tests at the .05 sig level). You found 3. With appropriately corrected Leopold
I suspect you will find there is indeed stat sig. similar trends incl. amplification.
Setting up the statistical testing should be interesting with this many combinations.
Regards, Tom
Ben Santer said the following on 12/14/2007 5:31 PM:
Dear Tom,
As promised, I've now repeated all of the significance testing involving
model-versus-observed trend differences, but this time using spatially-averaged T2 and
T2LT changes that are not "masked out" over tropical land areas. As I mentioned this
morning, the use of non-masked data facilitates a direct comparison with Douglass et al.
The results for combined changes over tropical land and ocean are very similar to those
I sent out yesterday, which were for T2 and T2LT changes over tropical oceans only:
COMBINED LAND/OCEAN RESULTS (WITH STANDARD ERRORS ADJUSTED FOR TEMPORAL AUTOCORRELATION
EFFECTS; SPATIAL AVERAGES OVER 20N-20S; ANALYSIS PERIOD 1979 TO 1999)
T2LT tests, RSS observational data: 0 out of 49 model-versus-observed trend differences
are significant at the 5% level.
T2LT tests, UAH observational data: 1 out of 49 model-versus-observed trend differences
are significant at the 5% level.
T2 tests, RSS observational data: 1 out of 49 model-versus-observed trend differences
are significant at the 5% level.
T2 tests, UAH observational data: 1 out of 49 model-versus-observed trend differences
are significant at the 5% level.
So our conclusion - that model tropical T2 and T2LT trends are, in virtually all
realizations and models, not significantly different from either RSS or UAH trends - is
not sensitive to whether we do the significance testing with "ocean only" or combined
"land+ocean" temperature changes.
With best regards, and happy holidays to all!
Ben
Thomas.R.Karl wrote:
Ben,
This is very informative. One question I raise is whether the results would have been
at all different if you had not masked the land. I doubt it, but it would be nice to
know.
Tom
Ben Santer said the following on 12/13/2007 9:58 PM:
Dear folks,
I've been doing some calculations to address one of the statistical issues raised by the
Douglass et al. paper in the International Journal of Climatology. Here are some of my
results.
Recall that Douglass et al. calculated synthetic T2LT and T2 temperatures from the
CMIP-3 archive of 20th century simulations ("20c3m" runs). They used a total of 67 20c3m
realizations, performed with 22 different models. In calculating the statistical
uncertainty of the model trends, they introduced sigma{SE}, an "estimate of the
uncertainty of the mean of the predictions of the trends". They defined
sigma{SE} as follows:
sigma{SE} = sigma / sqrt(N - 1), where
"N = 22 is the number of independent models".
As we've discussed in our previous correspondence, this definition has serious problems
(see comments from Carl and Steve below), and allows Douglass et al. to reach the
erroneous conclusion that modeled T2LT and T2 trends are significantly different from
the observed T2LT and T2 trends in both the RSS and UAH datasets. This comparison of
simulated and observed T2LT and T2 trends is given in Table III of Douglass et al.
[As an amusing aside, I note that the RSS datasets are referred to as "RSS" in this
table, while UAH results are designated as "MSU". I guess there's only one true "MSU"
dataset...]
I decided to take a quick look at the issue of the statistical significance of
differences between simulated and observed tropospheric temperature trends. My first cut
at this "quick look" involves only UAH and RSS observational data - I have not yet done
any tests with radiosonde datas, UMD T2 data, or satellite results from Zou et al.
I operated on the same 49 realizations of the 20c3m experiment that we used in Chapter 5
of CCSP 1.1. As in our previous work, all model results are synthetic T2LT and T2
temperatures that I calculated using a static weighting function approach. I have not
yet implemented Carl's more sophisticated method of estimating synthetic MSU
temperatures from model data (which accounts for effects of topography and land/ocean
differences). However, for the current application, the simple static weighting function
approach is more than adequate, since we are focusing on T2LT and T2 changes over
tropical oceans only - so topographic and land-ocean differences are unimportant. Note
that I still need to calculate synthetic MSU temperatures from about xxx xxxx xxxxc3m
realizations which were not in the CMIP-3 database at the time we were working on the
CCSP report. For the full response to Douglass et al., we should use the same 67 20c3m
realizations that they employed.
For each of the 49 realizations that I processed, I first masked out all tropical land
areas, and then calculated the spatial averages of monthly-mean, gridded T2LT and T2
data over tropical oceans (20N-20S). All model and observational results are for the
common 252-month period from January 1979 to December 1999 - the longest period of
overlap between the RSS and UAH MSU data and the bulk of the 20c3m runs. The simulated
trends given by Douglass et al. are calculated over the same 1979 to 1999 period;
however, they use a longer period (1979 to 2004) for calculating observational trends -
so there is an inconsistency between their model and observational analysis periods,
which they do not explain. This difference in analysis periods is a little puzzling
given that we are dealing with relatively short observational record lengths, resulting
in some sensitivity to end-point effects.
I then calculated anomalies of the spatially-averaged T2LT and T2 data (w.r.t.
climatological monthly-means over 1xxx xxxx xxxx), and fit least-squares linear trends to
model and observational time series. The standard errors of the trends were adjusted for
temporal autocorrelation of the regression residuals, as described in Santer et al.
(2000) ["Statistical significance of trends and trend differences in layer-average
atmospheric temperature time series"; JGR 105, 7xxx xxxx xxxx.]
Consider first panel A of the attached plot. This shows the simulated and observed T2LT
trends over 1979 to 1999 (again, over 20N-20S, oceans only) with their adjusted 1-sigma
confidence intervals). For the UAH and RSS data, it was possible to check against the
adjusted confidence intervals independently calculated by Dian during the course of work
on the CCSP report. Our adjusted confidence intervals are in good agreement. The grey
shaded envelope in panel A denotes the 1-sigma standard error for the RSS T2LT trend.
There are 49 pairs of UAH-minus-model trend differences and 49 pairs of RSS-minus-model
trend differences. We can therefore test - for each model and each 20c3m realization -
whether there is a statistically significant difference between the observed and
simulated trends.
Let bx and by represent any single pair of modeled and observed trends, with adjusted
standard errors s{bx} and s{by}. As in our previous work (and as in related work by John
Lanzante), we define the normalized trend difference d as:
d = (bx - by) / sqrt[ (s{bx})**2 + (s{by})**2 ]
Under the assumption that d is normally distributed, values of d > +1.96 or < -1.96
indicate observed-minus-model trend differences that are significant at the 5% level. We
are performing a two-tailed test here, since we have no information a priori about the
"direction" of the model trend (i.e., whether we expect the simulated trend to be
significantly larger or smaller than observed).
Panel c shows values of the normalized trend difference for T2LT trends.
the grey shaded area spans the range +1.96 to -1.96, and identifies the region where we
fail to reject the null hypothesis (H0) of no significant difference between observed
and simulated trends.
Consider the solid symbols first, which give results for tests involving RSS data. We
would reject H0 in only one out of 49 cases (for the CCCma-CGCM3.1(T47) model). The open
symbols indicate results for tests involving UAH data. Somewhat surprisingly, we get the
same qualitative outcome that we obtained for tests involving RSS data: only one of the
UAH-model trend pairs yields a difference that is statistically significant at the 5%
level.
Panels b and d provide results for T2 trends. Results are very similar to those achieved
with T2LT trends. Irrespective of whether RSS or UAH T2 data are used, significant trend
differences occur in only one of 49 cases.
Bottom line: Douglass et al. claim that "In all cases UAH and RSS satellite trends are
inconsistent with model trends." (page 6, lines 61-62). This claim is categorically
wrong. In fact, based on our results, one could justifiably claim that THERE IS ONLY ONE
CASE in which model T2LT and T2 trends are inconsistent with UAH and RSS results! These
guys screwed up big time.
SENSITIVITY TESTS
QUESTION 1: Some of the model-data trend comparisons made by Douglass et al. used
temperatures averaged over 30N-30S rather than 20N-20S. What happens if we repeat our
simple trend significance analysis using T2LT and T2 data averaged over ocean areas
between 30N-30S?
ANSWER 1: Very little. The results described above for oceans areas between 20N-20S are
virtually unchanged.
QUESTION 2: Even though it's clearly inappropriate to estimate the standard errors of
the linear trends WITHOUT accounting for temporal autocorrelation effects (the 252 time
sample are clearly not independent; effective sample sizes typically range from 6 to
56), someone is bound to ask what the outcome is when one repeats the paired trend tests
with non-adjusted standard errors. So here are the results:
T2LT tests, RSS observational data: 19 out of 49 trend differences are significant at
the 5% level.
T2LT tests, UAH observational data: 34 out of 49 trend differences are significant at
the 5% level.
T2 tests, RSS observational data: 16 out of 49 trend differences are significant at the
5% level.
T2 tests, UAH observational data: 35 out of 49 trend differences are significant at the
5% level.
So even under the naive (and incorrect) assumption that each model and observational
time series contains 252 independent time samples, we STILL find no support for Douglass
et al.'s assertion that: "In all cases UAH and RSS satellite trends are inconsistent
with model trends."
Q.E.D.
If Leo is agreeable, I'm hopeful that we'll be able to perform a similar trend
comparison using synthetic MSU T2LT and T2 temperatures calculated from the RAOBCORE
radiosonde data - all versions, not just v1.2!
As you can see from the email list, I've expanded our "focus group" a little bit, since
a number of you have written to me about this issue.
I am leaving for Miami on Monday, Dec. 17th. My Mom is having cataract surgery, and I'd
like to be around to provide her with moral and practical support. I'm not exactly sure
when I'll be returning to PCMDI - although I hope I won't be gone longer than a week. As
soon as I get back, I'll try to make some more progress with this stuff. Any suggestions
or comments on what I've done so far would be greatly appreciated. And for the time
being, I think we should not alert Douglass et al. to our results.
With best regards, and happy holidays! May all your "Singers" be carol singers, and not
of the S. Fred variety...
Ben
(P.S.: I noticed one unfortunate typo in Table II of Douglass et al. The MIROC3.2
(medres) model is referred to as "MIROC3.2_Merdes"....)
carl mears wrote:
Hi Steve
I'd say it's the equivalent of rolling a 6-sided die a hundred times, and
finding a mean value of ~3.5 and a standard deviation of ~1.7, and
calculating the standard error of the mean to be ~0.17 (so far so
good). An then rolling the die one more time, getting a 2, and
claiming that the die is no longer 6 sided because the new measurement
is more than 2 standard errors from the mean.
In my view, this problem trumps the other problems in the paper.
I can't believe Douglas is a fellow of the American Physical Society.
-Carl
At 02:07 AM 12/6/2007, you wrote:
If I understand correctly, what Douglass et al. did makes the stronger assumption that
unforced variability is *insignificant*. Their statistical test is logically equivalent
to falsifying a climate model because it did not consistently predict a particular storm
on a particular day two years from now.
Dr. Carl Mears
Remote Sensing Systems
438 First Street, Suite 200, Santa Rosa, CA 95401
[1]mears@xxxxxxxxx.xxx
xxx xxxx xxxxx21
xxx xxxx xxxx(fax))
--
*Dr. Thomas R. Karl, L.H.D.*
*/Director/*//
NOAA's National Climatic Data Center
Veach-Baley Federal Building
151 Patton Avenue
Asheville, NC 28xxx xxxx xxxx
Tel: (8xxx xxxx xxxx
Fax: (8xxx xxxx xxxx
[2]Thomas.R.Karl@xxxxxxxxx.xxx [3]<mailto:Thomas.R.Karl@xxxxxxxxx.xxx>
--
Dr. Thomas R. Karl, L.H.D.
Director
NOAA's National Climatic Data Center
Veach-Baley Federal Building
151 Patton Avenue
Asheville, NC 28xxx xxxx xxxx
Tel: (8xxx xxxx xxxx
Fax: (8xxx xxxx xxxx
[4]Thomas.R.Karl@xxxxxxxxx.xxx
References
1. mailto:mears@xxxxxxxxx.xxx
2. mailto:Thomas.R.Karl@xxxxxxxxx.xxx
3. mailto:Thomas.R.Karl@xxxxxxxxx.xxx
4. mailto:Thomas.R.Karl@xxxxxxxxx.xxx
Original Filename: 1198443017.txt | Return to the index page | Permalink | Later Emails
From: Leopold Haimberger <leopold.haimberger@xxxxxxxxx.xxx>
To: John.Lanzante@xxxxxxxxx.xxx
Subject: Re: [Fwd: sorry to take your time up, but really do need a scrub of this singer/christy/etc effort]
Date: Sun, 23 Dec 2007 15:50:17 +0100
Cc: "Thomas.R.Karl" <Thomas.R.Karl@xxxxxxxxx.xxx>, carl mears <mears@xxxxxxxxx.xxx>, "David C. Bader" <bader2@xxxxxxxxx.xxx>, "'Dian J. Seidel'" <dian.seidel@xxxxxxxxx.xxx>, "'Francis W. Zwiers'" <francis.zwiers@xxxxxxxxx.xxx>, Frank Wentz <frank.wentz@xxxxxxxxx.xxx>, Karl Taylor <taylor13@xxxxxxxxx.xxx>, Melissa Free <Melissa.Free@xxxxxxxxx.xxx>, "Michael C. MacCracken" <mmaccrac@xxxxxxxxx.xxx>, "'Philip D. Jones'" <p.jones@xxxxxxxxx.xxx>, santer1@xxxxxxxxx.xxx, Sherwood Steven <steven.sherwood@xxxxxxxxx.xxx>, Steve Klein <klein21@xxxxxxxxx.xxx>, 'Susan Solomon' <susan.solomon@xxxxxxxxx.xxx>, "Thorne, Peter" <peter.thorne@xxxxxxxxx.xxx>, Tim Osborn <t.osborn@xxxxxxxxx.xxx>, Tom Wigley <wigley@xxxxxxxxx.xxx>
<x-flowed>
Dear all,
I have attached a plot which summarizes the recent developments
concerning tropical radiosonde temperature datasets and which could be
a candidate to be included in a reply to Douglass et al.
It contains trend profiles from unadjusted radiosondes, HadAT2-adjusted
radiosondes, RAOBCORE (versions 1.2-1.4) adjusted radiosondes
and from radiosondes adjusted with a neighbor composite method (RICH)
that uses the break dates detected with RAOBCORE (v1.4) as metadata.
RAOBCORE v1.2,v1.3 are documented in Haimberger (2007), RAOBCORE v1.4
and RICH are discussed in the manuscript I mentioned in my previous email.
Latitude range is 20S-20N, only time series with less than 24 months of
missing data are included. Spatial sampling of all curves is the same
except HadAT which contains less stations that meet the 24month
criterion. Sampling uncertainty of the trend curves is ca.
+/-0.1K/decade (95% percentiles estimated with bootstrap method).
RAOBCORE v1.3,1.4 and RICH are results from ongoing research and warming
trends from radiosondes may still be underestimated.
The upper tropospheric warming maxima from RICH are even larger (up to
0.35K/decade, not shown), if only radiosondes within the tropics
(20N-20S) are allowed as reference for adjustment of tropical radiosonde
temperatures. The pink/blue curves in the attached plot should therefore
not be regarded as upper bound of what may be achieved with plausible
choices of reference series for homogenization.
Please let me know your comments.
I wish you a merry Christmas.
With best regards
Leo
John Lanzante wrote:
> Ben,
>
> Perhaps a resampling test would be appropriate. The tests you have performed
> consist of pairing an observed time series (UAH or RSS MSU) with each one
> of 49 GCM times series from your "ensemble of opportunity". Significance
> of the difference between each pair of obs/GCM trends yields a certain
> number of "hits".
>
> To determine a baseline for judging how likely it would be to obtain the
> given number of hits one could perform a set of resampling trials by
> treating one of the ensemble members as a surrogate observation. For each
> trial, select at random one of the 49 GCM members to be the "observation".
> From the remaining 48 members draw a bootstrap sample of 49, and perform
> 49 tests, yielding a certain number of "hits". Repeat this many times to
> generate a distribution of "hits".
>
> The actual number of hits, based on the real observations could then be
> referenced to the Monte Carlo distribution to yield a probability that this
> could have occurred by chance. The basic idea is to see if the observed
> trend is inconsistent with the GCM ensemble of trends.
>
> There are a couple of additional tweaks that could be applied to your method.
> You are currently computing trends for each of the two time series in the
> pair and assessing the significance of their differences. Why not first
> create a difference time series and assess the significance of it's trend?
> The advantage of this is that you would reduce somewhat the autocorrelation
> in the time series and hence the effect of the "degrees of freedom"
> adjustment. Since the GCM runs are based on coupled model runs this
> differencing would help remove the common externally forced variability,
> but not internally forced variability, so the adjustment would still be
> needed.
>
> Another tweak would be to alter the significance level used to assess
> differences in trends. Currently you are using the 5% level, which yields
> only a small number of hits. If you made this less stringent you would get
> potentially more weaker hits. But it would all come out in the wash so to
> speak since the number of hits in the Monte Carlo simulations would increase
> as well. I suspect that increasing the number of expected hits would make the
> whole procedure more powerful/efficient in a statistical sense since you
> would no longer be dealing with a "rare event". In the current scheme, using
> a 5% level with 49 pairings you have an expected hit rate of 0.05 X 49 = 2.45.
> For example, if instead you used a 20% significance level you would have an
> expected hit rate of 0.20 X 49 = 9.8.
>
> I hope this helps.
>
> On an unrelated matter, I'm wondering a bit about the different versions of
> Leo's new radiosonde dataset (RAOBCORE). I was surprised to see that the
> latest version has considerably more tropospheric warming than I recalled
> from an earlier version that was written up in JCLI in 2007. I have a
> couple of questions that I'd like to ask Leo. One concern is that if we use
> the latest version of RAOBCORE is there a paper that we can reference --
> if this is not in a peer-reviewed journal is there a paper in submission?
> The other question is: could you briefly comment on the differences in
> methodology used to generate the latest version of RAOBCORE as compared to
> the version used in JCLI 2007, and what/when/where did changes occur to
> yield a stronger warming trend?
>
> Best regards,
>
> ______John
>
>
>
> On Saturday 15 December 2007 12:21 pm, Thomas.R.Karl wrote:
>
>> Thanks Ben,
>>
>> You have the makings of a nice article.
>>
>> I note that we would expect to 10 cases that are significantly different
>> by chance (based on the 196 tests at the .05 sig level). You found 3.
>> With appropriately corrected Leopold I suspect you will find there is
>> indeed stat sig. similar trends incl. amplification. Setting up the
>> statistical testing should be interesting with this many combinations.
>>
>> Regards, Tom
>>
>
>
--
Ao. Univ. Prof. Dr. Leopold Haimberger
Institut für Meteorologie und Geophysik, Universität Wien
Althanstraße 14, A - 1090 Wien
Tel.: xxx xxxx xxxx
Fax.: xxx xxxx xxxx
http://mailbox.univie.ac.at/~haimbel7/
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From: Ben Santer <santer1@xxxxxxxxx.xxx>
To: John Lanzante <John.Lanzante@xxxxxxxxx.xxx>, Thomas R Karl <Thomas.R.Karl@xxxxxxxxx.xxx>, carl mears <mears@xxxxxxxxx.xxx>, "David C. Bader" <bader2@xxxxxxxxx.xxx>, "'Dian J. Seidel'" <dian.seidel@xxxxxxxxx.xxx>, "'Francis W. Zwiers'" <francis.zwiers@xxxxxxxxx.xxx>, Frank Wentz <frank.wentz@xxxxxxxxx.xxx>, Karl Taylor <taylor13@xxxxxxxxx.xxx>, Leopold Haimberger <leopold.haimberger@xxxxxxxxx.xxx>, Melissa Free <Melissa.Free@xxxxxxxxx.xxx>, "Michael C. MacCracken" <mmaccrac@xxxxxxxxx.xxx>, "'Philip D. Jones'" <p.jones@xxxxxxxxx.xxx>, Steven Sherwood <Steven.Sherwood@xxxxxxxxx.xxx>, Steve Klein <klein21@xxxxxxxxx.xxx>, 'Susan Solomon' <ssolomon@xxxxxxxxx.xxx>, "Thorne, Peter" <peter.thorne@xxxxxxxxx.xxx>, Tim Osborn <t.osborn@xxxxxxxxx.xxx>, Tom Wigley <wigley@xxxxxxxxx.xxx>, Gavin Schmidt <gschmidt@xxxxxxxxx.xxx>
Subject: More significance testing
Date: Thu, 27 Dec 2007 16:26:xxx xxxx xxxx
Reply-to: santer1@xxxxxxxxx.xxx
<x-flowed>
Dear folks,
This email briefly summarizes the trend significance test results. As I
mentioned in yesterday's email, I've added a new case (referred to as
"TYPE3" below). I've also added results for tests with a stipulated 10%
significance level. Here is the explanation of the four different types
of trend test:
1. "OBS-vs-MODEL": Observed MSU trends in RSS and UAH are tested against
trends in synthetic MSU data in 49 realizations of the 20c3m experiment.
Results from RSS and UAH are pooled, yielding a total of 98 tests for T2
trends and 98 tests for T2LT trends.
2. "MODEL-vs-MODEL (TYPE1)": Involves model data only. Trend in
synthetic MSU data in each of 49 20c3m realizations is tested against
each trend in the remaining 48 realizations (i.e., no trend tests
involving identical data). Yields a total of 49 x 48 = 2352 tests. The
significance of trend differences is a function of BOTH inter-model
differences (in climate sensitivity, applied 20c3m forcings, and the
amplitude of variability) AND "within-model" effects (i.e., is related
to the different manifestations of natural internal variability
superimposed on the underlying forced response).
3. "MODEL-vs-MODEL (TYPE2)": Involves model data only. Limited to the M
models with multiple realizations of the 20c3m experiment. For each of
these M models, the number of unique combinations C of N 20c3m
realizations into R trend pairs is determined. For example, in the case
of N = 5, C = N! / [ R!(N-R)! ] = 10. The significance of trend
differences is solely a function of "within-model" effects (i.e., is
related to the different manifestations of natural internal variability
superimposed on the underlying forced response). There are a total of 62
tests (not 124, as I erroneously reported yesterday!)
4. "MODEL-vs-MODEL (TYPE3)": Involves model data only. For each of the
19 models, only the first 20c3m realization is used. The trend in each
model's first 20c3m realization is tested against each trend in the
first 20c3m realization of the remaining 18 models. Yields a total of 19
x 18 = 342 tests. The significance of trend differences is solely a
function of inter-model differences (in climate sensitivity, applied
20c3m forcings, and the amplitude of variability).
REJECTION RATES FOR STIPULATED 5% SIGNIFICANCE LEVEL
Test type No. of tests T2 "Hits" T2LT "Hits"
1. OBS-vs-MODEL 49 x xxx xxxx xxxx(xxx xxxx xxxx(2.04%xxx xxxx xxxx(1.02%)
2. MODEL-vs-MODEL (TYPExxx xxxx xxxxx 48 (23xxx xxxx xxxx(2.47%xxx xxxx xxxx(1.36%)
3. MODEL-vs-MODEL (TYPExxx xxxx xxxx(xxx xxxx xxxx(0.00%xxx xxxx xxxx(0.00%)
4. MODEL-vs-MODEL (TYPExxx xxxx xxxxx 18 (3xxx xxxx xxxx(6.43%xxx xxxx xxxx(4.09%)
REJECTION RATES FOR STIPULATED 10% SIGNIFICANCE LEVEL
Test type No. of tests T2 "Hits" T2LT "Hits"
1. OBS-vs-MODEL 49 x xxx xxxx xxxx(xxx xxxx xxxx(4.08%xxx xxxx xxxx(2.04%)
2. MODEL-vs-MODEL (TYPExxx xxxx xxxxx 48 (23xxx xxxx xxxx(3.40%xxx xxxx xxxx(1.96%)
3. MODEL-vs-MODEL (TYPExxx xxxx xxxx(xxx xxxx xxxx(1.61%xxx xxxx xxxx(0.00%)
4. MODEL-vs-MODEL (TYPExxx xxxx xxxxx 18 (3xxx xxxx xxxx(8.19%xxx xxxx xxxx(5.85%)
REJECTION RATES FOR STIPULATED 20% SIGNIFICANCE LEVEL
Test type No. of tests T2 "Hits" T2LT "Hits"
1. OBS-vs-MODEL 49 x xxx xxxx xxxx(xxx xxxx xxxx(7.14%xxx xxxx xxxx(5.10%)
2. MODEL-vs-MODEL (TYPExxx xxxx xxxxx 48 (23xxx xxxx xxxx(7.48%xxx xxxx xxxx(4.25%)
3. MODEL-vs-MODEL (TYPExxx xxxx xxxx(xxx xxxx xxxx(6.45%xxx xxxx xxxx(4.84%)
4. MODEL-vs-MODEL (TYPExxx xxxx xxxxx 18 (3xxx xxxx xxxx(12.28%xxx xxxx xxxx(8.19%)
Features of interest:
A) As you might expect, for each of the three significance levels, TYPE3
tests yield the highest rejection rates of the null hypothesis of "No
significant difference in trend". TYPE2 tests yield the lowest rejection
rates. This is simply telling us that the inter-model differences in
trends tend to be larger than the "between-realization" differences in
trends in any individual model.
B) Rejection rates for the model-versus-observed trend tests are
consistently LOWER than for the model-versus-model (TYPE3) tests. On
average, therefore, the tropospheric trend differences between the
observational datasets used here (RSS and UAH) and the synthetic MSU
temperatures calculated from 19 CMIP-3 models are actually LESS
SIGNIFICANT than the inter-model trend differences arising from
differences in sensitivity, 20c3m forcings, and levels of variability.
I also thought that it would be fun to use the model data to explore the
implications of Douglass et al.'s flawed statistical procedure. Recall
that Douglass et al. compare (in their Table III) the observed T2 and
T2LT trends in RSS and UAH with the overall means of the multi-model
distributions of T2 and T2LT trends. Their standard error, sigma{SE}, is
meant to represent an "estimate of the uncertainty of the mean" (i.e.,
the mean trend). sigma{SE} is given as:
sigma{SE} = sigma / sqrt{N - 1}
where sigma is the standard deviation of the model trends, and N is "the
number of independent models" (22 in their case). Douglass et al.
apparently estimate sigma using ensemble-mean trends for each model (if
20c3m ensembles are available).
So what happens if we apply this procedure using model data only? This
is rather easy to do. As above (in the TYPE1, TYPE2, and TYPE3 tests), I
simply used the synthetic MSU trends from the 19 CMIP-3 models employed
in our CCSP Report and in Santer et al. 2005 (so N = 19). For each
model, I calculated the ensemble-mean 20c3m trend over 1979 to 1999
(where multiple 20c3m realizations were available). Let's call these
mean trends b{j}, where j (the index over models) = 1, 2, .. 19.
Further, let's regard b{1} as the surrogate observations, and then use
Douglass et al.'s approach to test whether b{1} is significantly
different from the overall mean of the remaining 18 members of b{j}.
Then repeat with b{2} as surrogate observations, etc. For each
layer-averaged temperature series, this yields 19 tests of the
significance of differences in mean trends.
To give you a feel for this stuff, I've reproduced below the results for
tests involving T2LT trends. The "OBS" column is the ensemble-mean T2LT
trend in the surrogate observations. "MODAVE" is the overall mean trend
in the 18 remaining members of the distribution, and "SIGMA" is the
1-sigma standard deviation of these trends. "SIGMA{SE}" is 1 x
SIGMA{SE} (note that Douglass et al. give 2 x SIGMA{SE} in their Table
III; multiplying our SIGMA{SE} results by two gives values similar to
theirs). "NORMD" is simply the normalized difference (OBS-MODAVE) /
SIGMA{SE}, and "P-VALUE" is the p-value for the normalized difference,
assuming that this difference is approximately normally distributed.
MODEL "OBS" MODAVE SIGMA SIGMA{SE} NORMD P-VALUE
CCSM3.xxx xxxx xxxx.1xxx xxxx xxxx.2xxx xxxx xxxx.0xxx xxxx xxxx.0xxx xxxx xxxx.7xxx xxxx xxxx.0052
GFDL2.xxx xxxx xxxx.2xxx xxxx xxxx.2xxx xxxx xxxx.0xxx xxxx xxxx.0xxx xxxx xxxx.0xxx xxxx xxxx.0359
GFDL2.xxx xxxx xxxx.3xxx xxxx xxxx.2xxx xxxx xxxx.0xxx xxxx xxxx.0xxx xxxx xxxx.4xxx xxxx xxxx.0000
GISS_EH 0.1xxx xxxx xxxx.2xxx xxxx xxxx.0xxx xxxx xxxx.0xxx xxxx xxxx.3xxx xxxx xxxx.0009
GISS_ER 0.1xxx xxxx xxxx.2xxx xxxx xxxx.0xxx xxxx xxxx.0xxx xxxx xxxx.0xxx xxxx xxxx.3075
MIROC3.2_Txxx xxxx xxxx.1xxx xxxx xxxx.2xxx xxxx xxxx.0xxx xxxx xxxx.0xxx xxxx xxxx.3xxx xxxx xxxx.0000
MIROC3.2_T106 0.2xxx xxxx xxxx.2xxx xxxx xxxx.0xxx xxxx xxxx.0xxx xxxx xxxx.7xxx xxxx xxxx.4651
MRI2.3.2a 0.2xxx xxxx xxxx.2xxx xxxx xxxx.0xxx xxxx xxxx.0xxx xxxx xxxx.2xxx xxxx xxxx.0013
PCM 0.1xxx xxxx xxxx.2xxx xxxx xxxx.0xxx xxxx xxxx.0xxx xxxx xxxx.2xxx xxxx xxxx.0013
HADCMxxx xxxx xxxx.1xxx xxxx xxxx.2xxx xxxx xxxx.0xxx xxxx xxxx.0xxx xxxx xxxx.0xxx xxxx xxxx.3018
HADGEMxxx xxxx xxxx.3xxx xxxx xxxx.2xxx xxxx xxxx.0xxx xxxx xxxx.0xxx xxxx xxxx.7xxx xxxx xxxx.0000
CCCMA3.xxx xxxx xxxx.4xxx xxxx xxxx.2xxx xxxx xxxx.0xxx xxxx xxxx.0xxx xxxx xxxx.1xxx xxxx xxxx.0000
CNRM3.xxx xxxx xxxx.2xxx xxxx xxxx.2xxx xxxx xxxx.0xxx xxxx xxxx.0xxx xxxx xxxx.2xxx xxxx xxxx.2019
CSIRO3.xxx xxxx xxxx.2xxx xxxx xxxx.2xxx xxxx xxxx.0xxx xxxx xxxx.0xxx xxxx xxxx.1xxx xxxx xxxx.0018
ECHAMxxx xxxx xxxx.1xxx xxxx xxxx.2xxx xxxx xxxx.0xxx xxxx xxxx.0xxx xxxx xxxx.4xxx xxxx xxxx.0000
IAP_FGOALS1.0 0.1xxx xxxx xxxx.2xxx xxxx xxxx.0xxx xxxx xxxx.0xxx xxxx xxxx.5xxx xxxx xxxx.1257
GISS_AOM 0.1xxx xxxx xxxx.2xxx xxxx xxxx.0xxx xxxx xxxx.0xxx xxxx xxxx.7xxx xxxx xxxx.0788
INMCM3.xxx xxxx xxxx.0xxx xxxx xxxx.2xxx xxxx xxxx.0xxx xxxx xxxx.0xxx xxxx xxxx.0xxx xxxx xxxx.0000
IPSL_CMxxx xxxx xxxx.2xxx xxxx xxxx.2xxx xxxx xxxx.0xxx xxxx xxxx.0xxx xxxx xxxx.5xxx xxxx xxxx.5920
T2LT: No. of p-values .le. 0.05: 12. Rejection rate: 63.16%
T2LT: No. of p-values .le. 0.10: 13. Rejection rate: 68.42%
T2LT: No. of p-values .le. 0.20: 14. Rejection rate: 73.68%
The corresponding rejection rates for the tests involving T2 data are:
T2: No. of p-values .le. 0.05: 12. Rejection rate: 63.16%
T2: No. of p-values .le. 0.10: 13. Rejection rate: 68.42%
T2: No. of p-values .le. 0.20: 15. Rejection rate: 78.95%
Bottom line: If we applied Douglass et al.'s ridiculous test of
difference in mean trends to model data only - in fact, to virtually the
same model data they used in their paper - one would conclude that
nearly two-thirds of the individual models had trends that were
significantly different from the multi-model mean trend! To follow
Douglass et al.'s flawed logic, this would mean that two-thirds of the
models really aren't models after all...
Happy New Year to all of you!
With best regards,
Ben
----------------------------------------------------------------------------
Benjamin D. Santer
Program for Climate Model Diagnosis and Intercomparison
Lawrence Livermore National Laboratory
P.O. Box 808, Mail Stop L-103
Livermore, CA 94550, U.S.A.
Tel: (9xxx xxxx xxxx
FAX: (9xxx xxxx xxxx
email: santer1@xxxxxxxxx.xxx
----------------------------------------------------------------------------
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From: Leopold Haimberger <leopold.haimberger@xxxxxxxxx.xxx>
To: santer1@xxxxxxxxx.xxx
Subject: Re: [Fwd: sorry to take your time up, but really do need a scrub of this singer/christy/etc effort]
Date: Sat, 29 Dec 2007 22:10:30 +0100
Cc: John.Lanzante@xxxxxxxxx.xxx, "Thomas.R.Karl" <Thomas.R.Karl@xxxxxxxxx.xxx>, carl mears <mears@xxxxxxxxx.xxx>, "David C. Bader" <bader2@xxxxxxxxx.xxx>, "'Dian J. Seidel'" <dian.seidel@xxxxxxxxx.xxx>, "'Francis W. Zwiers'" <francis.zwiers@xxxxxxxxx.xxx>, Frank Wentz <frank.wentz@xxxxxxxxx.xxx>, Karl Taylor <taylor13@xxxxxxxxx.xxx>, Melissa Free <Melissa.Free@xxxxxxxxx.xxx>, "Michael C. MacCracken" <mmaccrac@xxxxxxxxx.xxx>, "'Philip D. Jones'" <p.jones@xxxxxxxxx.xxx>, Sherwood Steven <steven.sherwood@xxxxxxxxx.xxx>, Steve Klein <klein21@xxxxxxxxx.xxx>, 'Susan Solomon' <susan.solomon@xxxxxxxxx.xxx>, "Thorne, Peter" <peter.thorne@xxxxxxxxx.xxx>, Tim Osborn <t.osborn@xxxxxxxxx.xxx>, Tom Wigley <wigley@xxxxxxxxx.xxx>
<x-flowed>
Ben,
I have attached the tropical mean trend profiles, now for the period
1xxx xxxx xxxx.
RAOBCORE versions show much more upper tropospheric heating for this
period, RICH shows slightly more heating.
Note also stronger cooling of unadjusted radiosondes in stratospheric
layers compared to 1xxx xxxx xxxx.
Just for information I have included also zonal mean trend plots for the
unadjusted radiosondes (tm), RAOBCORE v1.4 (tmcorr) and RICH (rgmra)
I do not suggest that these plots should be included but some of you
maybe want to know about the spatial coherence
of the zonal mean trends. It is interesting to see the lower
tropospheric warming minimum in the tropics in all three plots,
which I cannot explain. I believe it is spurious but it is remarkably
robust against my adjustment efforts.
Meridional resolution is 10 degrees.
As you can imagine, the tropical upper tropospheric heating maximum at
5S and the cooling in the unadjusted radiosondes at 5N are
based on very few long records in these belts. 2-3 in 5S, about 5 in 5N.
Best regards and I wish you all a happy new year.
Leo
Ben Santer wrote:
> Dear Leo,
>
> The Figure that you sent is extremely informative, and would be great
> to include in a response to Douglass et al. The Figure clearly
> illustrates that the "structural uncertainties" inherent in
> radiosonde-based estimates of tropospheric temperature change are much
> larger than Douglass et al. have claimed. This is an important point
> to make.
>
> Would it be possible to produce a version of this Figure showing
> results for the period 1979 to 1999 (the period that I've used for
> testing the significance of model-versus-observed trend differences)
> instead of 1979 to 2004?
>
> With best regards, and frohes Neues Jahr!
>
> Ben
> Leopold Haimberger wrote:
>> Dear all,
>>
>> I have attached a plot which summarizes the recent developments
>> concerning tropical radiosonde temperature datasets and which could
>> be a candidate to be included in a reply to Douglass et al.
>> It contains trend profiles from unadjusted radiosondes,
>> HadAT2-adjusted radiosondes, RAOBCORE (versions 1.2-1.4) adjusted
>> radiosondes
>> and from radiosondes adjusted with a neighbor composite method (RICH)
>> that uses the break dates detected with RAOBCORE (v1.4) as metadata.
>> RAOBCORE v1.2,v1.3 are documented in Haimberger (2007), RAOBCORE v1.4
>> and RICH are discussed in the manuscript I mentioned in my previous
>> email.
>> Latitude range is 20S-20N, only time series with less than 24 months
>> of missing data are included. Spatial sampling of all curves is the
>> same except HadAT which contains less stations that meet the 24month
>> criterion. Sampling uncertainty of the trend curves is ca.
>> +/-0.1K/decade (95% percentiles estimated with bootstrap method).
>>
>> RAOBCORE v1.3,1.4 and RICH are results from ongoing research and
>> warming trends from radiosondes may still be underestimated.
>> The upper tropospheric warming maxima from RICH are even larger (up
>> to 0.35K/decade, not shown), if only radiosondes within the tropics
>> (20N-20S) are allowed as reference for adjustment of tropical
>> radiosonde temperatures. The pink/blue curves in the attached plot
>> should therefore not be regarded as upper bound of what may be
>> achieved with plausible choices of reference series for homogenization.
>> Please let me know your comments.
>>
>> I wish you a merry Christmas.
>>
>> With best regards
>>
>> Leo
>>
>> John Lanzante wrote:
>>> Ben,
>>>
>>> Perhaps a resampling test would be appropriate. The tests you have
>>> performed
>>> consist of pairing an observed time series (UAH or RSS MSU) with
>>> each one
>>> of 49 GCM times series from your "ensemble of opportunity".
>>> Significance
>>> of the difference between each pair of obs/GCM trends yields a certain
>>> number of "hits".
>>>
>>> To determine a baseline for judging how likely it would be to obtain
>>> the
>>> given number of hits one could perform a set of resampling trials by
>>> treating one of the ensemble members as a surrogate observation. For
>>> each
>>> trial, select at random one of the 49 GCM members to be the
>>> "observation".
>>> From the remaining 48 members draw a bootstrap sample of 49, and
>>> perform
>>> 49 tests, yielding a certain number of "hits". Repeat this many
>>> times to
>>> generate a distribution of "hits".
>>>
>>> The actual number of hits, based on the real observations could then be
>>> referenced to the Monte Carlo distribution to yield a probability
>>> that this
>>> could have occurred by chance. The basic idea is to see if the observed
>>> trend is inconsistent with the GCM ensemble of trends.
>>>
>>> There are a couple of additional tweaks that could be applied to
>>> your method.
>>> You are currently computing trends for each of the two time series
>>> in the
>>> pair and assessing the significance of their differences. Why not first
>>> create a difference time series and assess the significance of it's
>>> trend?
>>> The advantage of this is that you would reduce somewhat the
>>> autocorrelation
>>> in the time series and hence the effect of the "degrees of freedom"
>>> adjustment. Since the GCM runs are based on coupled model runs this
>>> differencing would help remove the common externally forced
>>> variability,
>>> but not internally forced variability, so the adjustment would still be
>>> needed.
>>>
>>> Another tweak would be to alter the significance level used to assess
>>> differences in trends. Currently you are using the 5% level, which
>>> yields
>>> only a small number of hits. If you made this less stringent you
>>> would get
>>> potentially more weaker hits. But it would all come out in the wash
>>> so to
>>> speak since the number of hits in the Monte Carlo simulations would
>>> increase
>>> as well. I suspect that increasing the number of expected hits would
>>> make the
>>> whole procedure more powerful/efficient in a statistical sense since
>>> you
>>> would no longer be dealing with a "rare event". In the current
>>> scheme, using
>>> a 5% level with 49 pairings you have an expected hit rate of 0.05 X
>>> 49 = 2.45.
>>> For example, if instead you used a 20% significance level you would
>>> have an
>>> expected hit rate of 0.20 X 49 = 9.8.
>>>
>>> I hope this helps.
>>>
>>> On an unrelated matter, I'm wondering a bit about the different
>>> versions of
>>> Leo's new radiosonde dataset (RAOBCORE). I was surprised to see that
>>> the
>>> latest version has considerably more tropospheric warming than I
>>> recalled
>>> from an earlier version that was written up in JCLI in 2007. I have a
>>> couple of questions that I'd like to ask Leo. One concern is that if
>>> we use
>>> the latest version of RAOBCORE is there a paper that we can
>>> reference --
>>> if this is not in a peer-reviewed journal is there a paper in
>>> submission?
>>> The other question is: could you briefly comment on the differences
>>> in methodology used to generate the latest version of RAOBCORE as
>>> compared to the version used in JCLI 2007, and what/when/where did
>>> changes occur to
>>> yield a stronger warming trend?
>>>
>>> Best regards,
>>>
>>> ______John
>>>
>>>
>>>
>>> On Saturday 15 December 2007 12:21 pm, Thomas.R.Karl wrote:
>>>
>>>> Thanks Ben,
>>>>
>>>> You have the makings of a nice article.
>>>>
>>>> I note that we would expect to 10 cases that are significantly
>>>> different by chance (based on the 196 tests at the .05 sig level).
>>>> You found 3. With appropriately corrected Leopold I suspect you
>>>> will find there is indeed stat sig. similar trends incl.
>>>> amplification. Setting up the statistical testing should be
>>>> interesting with this many combinations.
>>>>
>>>> Regards, Tom
>>>>
>>>
>>>
>>
>
>
--
Ao. Univ. Prof. Dr. Leopold Haimberger
Institut für Meteorologie und Geophysik, Universität Wien
Althanstraße 14, A - 1090 Wien
Tel.: xxx xxxx xxxx
Fax.: xxx xxxx xxxx
http://mailbox.univie.ac.at/~haimbel7/
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From: Susan Solomon <Susan.Solomon@xxxxxxxxx.xxx>
To: Tom Wigley <wigley@xxxxxxxxx.xxx>, "Thomas.R.Karl" <Thomas.R.Karl@xxxxxxxxx.xxx>
Subject: Re: Douglass et al. paper
Date: Sun, 30 Dec 2007 10:18:xxx xxxx xxxx
Cc: John.Lanzante@xxxxxxxxx.xxx, carl mears <mears@xxxxxxxxx.xxx>, "David C. Bader" <bader2@xxxxxxxxx.xxx>, "'Dian J. Seidel'" <dian.seidel@xxxxxxxxx.xxx>, "'Francis W. Zwiers'" <francis.zwiers@xxxxxxxxx.xxx>, Frank Wentz <frank.wentz@xxxxxxxxx.xxx>, Karl Taylor <taylor13@xxxxxxxxx.xxx>, Leopold Haimberger <leopold.haimberger@xxxxxxxxx.xxx>, Melissa Free <Melissa.Free@xxxxxxxxx.xxx>, "Michael C. MacCracken" <mmaccrac@xxxxxxxxx.xxx>, "'Philip D. Jones'" <p.jones@xxxxxxxxx.xxx>, santer1@xxxxxxxxx.xxx, Sherwood Steven <steven.sherwood@xxxxxxxxx.xxx>, Steve Klein <klein21@xxxxxxxxx.xxx>, "Thorne, Peter" <peter.thorne@xxxxxxxxx.xxx>, Tim Osborn <t.osborn@xxxxxxxxx.xxx>, Tom Wigley <wigley@xxxxxxxxx.xxx>, myles <m.allen1@xxxxxxxxx.xxx>, Bill Fulkerson <wfulk@xxxxxxxxx.xxx>
<x-flowed>
Dear All,
Thanks very much for the helpful discussion on these issues.
I write to make a point that may not be well
recognized regarding the character of the
temperature trends in the lowermost
stratosphere/upper troposphere. I have already
discussed this with Ben but want to share with
others since I believe it is relevant to this
controversy at least at some altitudes. The
question I want to raise is not related to the
very important dialogue on how to handle the
errors and the statistics, but rather how to
think about the models.
The attached paper by Forster et al. appeared
recently in GRL. It taught me something I
didn't realize, namely that ozone losses and
accompanying temperature trends at higher
altitudes can strongly affect lower altitudes,
through the influence of downwelling longwave.
There is now much evidence that ozone has
decreased significantly in the tropics near 70
mbar. What we show in the attached paper by
Forster et al is that ozone depletion near 70
mbar affects temperatures not only at that level,
but also down to lower altitudes. I think this
is bound to be important to the tropical
temperature trends at least in the xxx xxxx xxxxmbar
height range, possibly lower down as well,
depending upon the degree to which there is a
'substratosphere' that is more radiatively
influenced than the rest of the troposphere.
Whether it can have an influence as low as 200
mbar - I don't know. But note that having an
influence could mean reducing the warming there,
not necessarily flipping it over to a net
cooling. This 'long-distance' physics, whereby
ozone depletion and associated cooling up high
can affect the thermal structure lower down, is
not a point I had understood despite many years
of studying the problem so I thought it
worthwhile to point it out to you here. It has
often been said (I probably said it myself five
years ago) that ozone losses and associated
cooling can't happen or aren't important in this
region - but that is wrong.
Further, the fundamental point made in the paper
of Thompson and Solomon a few years back remains
worth noting, and is, I believe, now resolved in
the more recent Forster et al paper: that the
broad structure of the temperature trends, with
quite large cooing in the lowermost stratosphere
in the tropics, comparable to that seen at higher
latitudes, is a feature NOT explained by e.g. CO2
cooling, but now can be explained by the observed
ozone losses. Exactly how big the tropical
cooling is, and exactly how low down it goes,
remains open to quantitative question and
improvement of radiosonde datasets. But I
believe the fundamental point we made in 2005
remains true: the temperature trends in the
lower stratosphere in the tropics are, even with
corrections, quite comparable to that seen at
other latitudes. We can now say it is surely
linked to the now-well-observed trends in ozone
there. The new paper further shows that you
don't have to have ozone trends at 100 mbar to
have a cooling there, due to down-welling
longwave, possibly lower down still. Whether
enhanced upwelling is a factor is a central
question.
No global general circulation model can possibly
be expected to simulate this correctly unless it
has interactive ozone, or prescribes an observed
tropical ozone trend. The AR4 models did not
include this, and any 'discrepancies' are not
relevant at all to the issue of the fidelity of
those models for global warming. So in closing
let me just say that just how low down this
effect goes needs more study, but that it does
happen and is relevant to the key problem of
tropical temperature trends is one that I hope
this email has clarified.
Happy new year,
Susan
At 6:13 PM -0700 12/29/07, Tom Wigley wrote:
>Tom,
>
>Yes -- I had this in an earlier version, but I did not want to
>overwhelm people with the myriad errors in the D et al. paper.
>
>I liked the attached item -- also in an earlier version.
>
>Tom.
>
>+++++++++++++
>
>Thomas.R.Karl wrote:
>
>>Tom,
>>
>>This is a very nice set of slides clearly
>>showing the problem with the Douglass et al
>>paper. One other aspect of this issue that
>>John L has mentioned and we discussed when we
>>were doing SAP 1.1 relates to difference
>>series. I am not sure whether Ben was
>>calculating the significance of the difference
>>series between sets of observations and model
>>simulations (annually). This would help offset
>>the effects of El-Nino and Volcanoes on the
>>trends.
>>
>>Tom K.
>>
>>Tom Wigley said the following on 12/29/2007 1:05 PM:
>>
>>>Dear all,
>>>
>>>I was recently at a meeting in Rome where Fred Singer was a participant.
>>>He was not on the speaker list, but, in
>>>advance of the meeting, I had thought
>>>he might raise the issue of the Douglass et
>>>al. paper. I therefore prepared the
>>>attached power point -- modified slightly since returning from Rome. As it
>>>happened, Singer did not raise the Douglass et al. issue, so I did not use
>>>the ppt. Still, it may be useful for members
>>>of this group so I am sending it
>>>to you all.
>>>
>>>Please keep this in confidence. I do not want
>>>it to get back to Singer or any
>>>of the Douglass et al. co-authors -- at least
>>>not at this stage while Ben is still
>>>working on a paper to rebut the Douglass et al. claims.
>>>
>>>On slide 6 I have attributed the die tossing
>>>argument to Carl Mears -- but, in
>>>looking back at my emails I can't find the
>>>original. If I've got this attribution
>>>wrong, please let me know.
>>>
>>>Other comments are welcome. Mike MacCracken and Ben helped in putting
>>>this together -- thanks to both.
>>>
>>>Tom.
>>>
>>>++++++++++++++++++++++++++++++++++++++++
>>
>>
>>--
>>
>>*Dr. Thomas R. Karl, L.H.D.*
>>
>>*/Director/*//
>>
>>NOAA's National Climatic Data Center
>>
>>Veach-Baley Federal Building
>>
>>151 Patton Avenue
>>
>>Asheville, NC 28xxx xxxx xxxx
>>
>>Tel: (8xxx xxxx xxxx
>>
>>Fax: (8xxx xxxx xxxx
>>
>>Thomas.R.Karl@xxxxxxxxx.xxx <mailto:Thomas.R.Karl@xxxxxxxxx.xxx>
>>
>
>
>
>Attachment converted: Junior:Comment on Douglass.ppt (SLD3/
Original Filename: 1199286511.txt | Return to the index page | Permalink | Later Emails
From: Peter Thorne <peter.thorne@xxxxxxxxx.xxx>
To: Susan Solomon <Susan.Solomon@xxxxxxxxx.xxx>
Subject: Re: Douglass et al. paper
Date: Wed, 02 Jan 2008 10:08:31 +0000
Cc: Tom Wigley <wigley@xxxxxxxxx.xxx>, Thomas R Karl <Thomas.R.Karl@xxxxxxxxx.xxx>, John Lanzante <John.Lanzante@xxxxxxxxx.xxx>, Carl Mears <mears@xxxxxxxxx.xxx>, "David C. Bader" <bader2@xxxxxxxxx.xxx>, Dian Seidel <dian.seidel@xxxxxxxxx.xxx>, "'Francis W. Zwiers'" <francis.zwiers@xxxxxxxxx.xxx>, Frank Wentz <frank.wentz@xxxxxxxxx.xxx>, Karl Taylor <taylor13@xxxxxxxxx.xxx>, Leopold Haimberger <leopold.haimberger@xxxxxxxxx.xxx>, Melissa Free <melissa.free@xxxxxxxxx.xxx>, "Michael C. MacCracken" <mmaccrac@xxxxxxxxx.xxx>, Phil Jones <p.jones@xxxxxxxxx.xxx>, Ben Santer <santer1@xxxxxxxxx.xxx>, Steve Sherwood <Steven.Sherwood@xxxxxxxxx.xxx>, Steve Klein <klein21@xxxxxxxxx.xxx>, Tim Osborn <t.osborn@xxxxxxxxx.xxx>, Tom Wigley <wigley@xxxxxxxxx.xxx>, Myles Allen <m.allen1@xxxxxxxxx.xxx>, Bill Fulkerson <wfulk@xxxxxxxxx.xxx>
Susan et al.,
I had also seen the Forster et al paper and was glad to see he had
followed up on work and ideas we had discussed some years ago when he
was at Reading and from the Exeter workshop. At the time I had done some
simple research on whether the stratosphere could affect the tropical
troposphere - possibly through convection modification or radiative
cooling. I'd done a simple timeseries regression of T2LT=a*Tsurf+b*T4+c
and got some regression coefficients out that suggested an influence.
Now, this was with old and now discredited data and the Fu et al.
technique has since superseded it to some extent (or at least cast
considerable doubt upon its efficacy) ... it would certainly be hard to
prove in a regression what was cause and effect with such broad
weighting functions even using T2LT which still isn't *really*
independent from T4.
But one thing I did do to try to "prove" the regression result was real
is take the composite differences between QBO phases on 45 years of
detrended (can't remember exactly how but I think I took differences
from decadally filtered data) data from radiosondes (HadAT1 at the
time). This showed a really very interesting result and suggested that
this communication if it was real went quite far down in to the
troposphere and was statistically significant, particularly in those
seasons when the ITCZ and QBO were geographically coincident. I attach
the slide for interest. I think this is the only scientifically valid
part of the analysis that I would stand by today given the rather
massive developments since. I doubt that raobs inhomogeneities could
explain the plot result as they project much more onto the trend than
they would onto this type of analysis.
The cooling stratosphere may really have an influence even quite low
down if this QBO composite technique is a good analogue for a cooling
startosphere's impact, and timeseries regression analysis supports it in
some obs (it would be interesting to repeat such an analysis with the
newer obs but I don't have time). A counter, however, is that surely the
models do radiation so those with ozone loss should do a good job of
this effect. This could be checked in Ben's ensemble in a poor man's
sense at least because some have ozone depletion and some don't.
The only way this could be a real factor not picked by the models, I
concluded at the time, is if models are far too keen to trigger
convection and that any real-world increased radiative cooling
efficiency effect is masked in the models because they convect far too
often and regain CAPE closure as a condition.
On another matter, we seem to be concentrating entirely on layer-average
temperatures. This is fine, but we know from CCSP these show little in
the way of differences. The key, and much harder test is to capture the
differences in behaviour between layers / levels - the "amplification"
behaviour. This was the focus of Santer et al. and I still believe is
the key scientific question given that each model realisation is
inherently so different but that we believe the physics determining the
temperature profile to be the key test that has to be answered. Maybe we
need to step back and rephrase the question in terms of the physics
rather than aiming solely to rebutt Douglass et al? In this case the key
physical questions in my view would be:
1. Why is there such strong evidence from sondes for a minima at c. 500?
Is this because it is near the triple point of water in the tropics? Or
at the top of the shallow convection? Or simply an artefact? [I don't
have any good ideas how we would answer the first two of these
questions]
2. Is there really a stratospheric radiative influence? If so, how low
does it go? What is the cause? Are the numbers consistent with the
underlying governing physics or simply an artefact of residual obs
errors?
3. Can any models show trend behaviour that deviates from a SALR on
multi-decadal timescales? If so, what is it about the model that causes
this effect? Physics? Forcings? Phasing of natural variability? Is it
also true on shorter timescales in this model?
It seems to me that trying to do an analysis based upon such physical
understanding / questions will clarify things far better than simply
doing another set of statistical analysis. I'm still particularly
interested if #2 is really true in the raobs (its not possible to do
with satellites I suspect, but if it is true it means we need to
massively rethink Fu et al. type analysis at least in the tropics) and
would be interested in helping someone follow up on that ... I think in
the future the Forster et al paper may be seen as the more
scientifically significant result when Douglass et al is no longer cared
about ...
Happy new year to you all.
Peter
--
Peter Thorne Climate Research Scientist
Met Office Hadley Centre, FitzRoy Road, Exeter, EX1 3PB
tel. xxx xxxx xxxxfax xxx xxxx xxxx
www.metoffice.gov.uk/hadobs
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From: Susan Solomon <Susan.Solomon@xxxxxxxxx.xxx>
To: P.Jones@xxxxxxxxx.xxx, Kevin Trenberth <trenbert@xxxxxxxxx.xxx>
Subject: Re: urban stuff
Date: Wed, 02 Jan 2008 14:59:xxx xxxx xxxx
Cc: Phil Jones <p.jones@xxxxxxxxx.xxx>
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Phil
Thanks for the Benestad reference, which I hadn't seen and will read
with interest.
Please keep me in the loop on your reprints.
I'm aware of the work with Dave Thompson, which is very interesting.
Happy new year to you too.
We can all look back on 2007 as a year in which we, the scientists,
did a fantastic job.
best
Susan
At 8:59 PM +0000 1/2/08, P.Jones@xxxxxxxxx.xxx wrote:
> Kevin, Susan,
> Working on several things at the moment, so won't
> have much time for a few weeks. Rasmus Benestad of
> the Norwegian Met Service wrote a paper on a very similar
> earlier verion of this McKittrick/Michaels paper (both
> were in Climate Research). There is nothing new in this
> paper in JGR.
> The only thing new in both this JGR paper and the
> Douglass et al one in IJC is the awful reviewing!!!!
> Rebuttals help, but often the damage is done once the
> paper comes out. The MM paper is bad, but the reviewing
> is even worse. Why did MM refer to an erratum on their
> paper which is essentially the same? Any reviewer worth
> any salt should have spotted that and then they would have
> seen the Benestad comment, which MM surprisingly don't refer to.
>
> I'm hoping to submit a paper on urbanization soon -
> based on work with Chinese series - this relates to the
> fraud allegation against Wei-Chyung Wang that Kevin knows
> about.
>
> Also should be a press release tomorrow or Friday about
> the forecast for 2008 temperatures. La Nina looks like making
> it coolish - cooler just than all years since 2001 (including
> 2001) and 1998. Pointing out that 2xxx xxxx xxxxis 0.21 warmer
> than 1xxx xxxx xxxxwhich is exactly as it should be with ghg-related
> warming of 0.2 per decade.
>
> [Also working on something with Dave Thompson (Dave's laeding)
> that will have an ENSO-factored out (and COWL) global T series.]
>
>
> We're (with the Met Office) extending the press release
> due to the silly coverage in mid-December about global warming
> ending, as all years since 1998 are cooler than it. Mostly this
> was by people just parrotting the same message from the same
> people. It is a case of people who should know better (and check
> their sources) just copying from people who don't know any
> better.
>
> Oh - forgot - Happy New Year!
>
> Any pictures on the IPCC web site of Oslo on Dec 10 !
>
> Patchy is on the front cover of the last issue of the 2007 in Nature.
>
> Cheers
> Phil
>
>
> Susan
>> Not me. Phil has been involved in various stuff related to this but I
>> am not up to speed. I'll cc him.
>> I recall some exchanges a while ago now.
>> Kevin
>>
>> Susan Solomon wrote:
>>> Kevin
>>> Happy new year to you. All's well here. Have you or other
>>> colleagues organized a rebuttal to the McKitrick and Michaels JGR 2007
>>> material on urbanization? It's getting exposure, along with the
>>> Douglass et al. paper. On the latter, you probably know Ben Santer is
>>> preparing one.
>>> best
>>> Susan
>>
>> --
>> ****************
>> Kevin E. Trenberth e-mail: trenbert@xxxxxxxxx.xxx
>> Climate Analysis Section, www.cgd.ucar.edu/cas/trenbert.html
>> NCAR
>> P. O. Box 3000, (3xxx xxxx xxxx
>> Boulder, CO 80xxx xxxx xxxx (3xxx xxxx xxxx(fax)
>>
>> Street address: 1850 Table Mesa Drive, Boulder, CO 80305
>>
>>
>>
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