Wednesday, May 16, 2012

4286.txt

date: Tue, 28 Jun 2005 09:27:43 -0600
from: Jonathan Overpeck <jtoatXYZxyzrizona.edu>
subject: [Wg1-ar4-ch06] abrupt and Important thoughts on References
to: wg1-ar4-ch06atXYZxyzs.ucar.edu

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Hi all - thanks Fortunat and Stefan for more debate on the 1470.
Sounds like the final decision is up to Eystein, but I can guess the
way he's thinking.

With regard to refs - remember that our goal is to cut the number of
references significantly. Since this is an assessment and not a
review, we can delete all but the most recent and comprehensive
references. I don't like cutting out the original refs any more than
you, but we just don't have room, and its more important to have text
than exhaustive references. Our colleagues will hopefully understand,
and if they don't then they need to do an ego check. It's more
important that we make an impact with policy makers rather than with
citation indices.

Does this make sense?

In any case, please help make sure we trim the total references DOWN
in number by a significant number. This is not happening the to
degree it should.

Also, please not that in the US, the US Congress is questioning
whether it is ethical for IPCC authors to be using the IPCC to
champion their own work/opinions. Obviously, this is wrong and scary,
but if our goal is to get policy makers (liberal and conservative
alike) to take our chapter seriously, it will only hurt our effort if
we cite too many of our own papers (perception is often reality).
PLEASE do not cite anything that is not absolutely needed, and please
do not cite your papers unless they are absolutely needed. Common
sense, but it isn't happening. Please be more critical with your
citations so we save needed space, and also so we don't get perceived
as self serving or worse.

Again, we can debate this if anyone thinks I've gone off the deep end.

Thanks, peck
PS - this is not to say anything critical of the refs Fortunat is
suggesting - we must cite the most relevant papers, and we must be as
up to date as possible.


>Peck and all,
>
>Fully agree. This '1470' yr periodicity is highly controversial and I
>was never convinced.
>We can use the space for better things that are relevant in the context
>of the anthropogenic GHG perturbation.
>
>I miss the recent and relevant literature. Examples are Pahnke and Zahn,
>Science, 2005 and Stocker and Johnsen, Paleoceanography 18, 2003, and
>Knutti et al., Nature, 2004
>Hemitt et al., Rev Geophysics, 2004 might be a good reference for
>Heinrich events.
>
>
>
>Regards,
>
>Fortunat
>
>
>Jonathan Overpeck wrote:
>>
>> Hi guys - I'm not aware of the age model changes that Eystein is
>> talking about (however, I'm not in the Euro meeting circles, and
>> trust he's right), but I know of several studies (e.g., U/Th dated
>> (well dated) spelothem studies (plus C14 Cariaco) that indicate that
>> the GISP/GRIP age models are off by quite a bit pre 40kish. The other
>> studies agree, so it makes sense to me that the ice core gangs are
>> revising their age models. Regardless of the probabilities (note that
>> one finds evidence in quasi-periodic variance most all paleo
>> records), this significant age model change means that the "1470
>> beat" has to be off/wrong or something else other than we've been led
>> to believe. For the sake of playing it safe, we should play this beat
>> way down until there is new evidence that is more convincing that it
>> is for real. We can mention it, but we make it clear that the
>> evidence for it is not all that strong - at best.
>>
>> I'll cc this to Fortunat and Valerie too - we don't want to rush to
>> conclusions w/o good discussion.
>>
>> Thanks, Peck
>>
>> >Hi Eystein,
>> >
>> >concerning your comment on the 1470-year beat: I'm aware that in the
>> >new time scale, it is less regular (at least I heard this, have not
>> >tested myself yet).
>> >
>> >If you have two time scales, one showing a regularity and one not,
>> >then there are two possibilities.
>> >(1) The regular one is correct, in the other one the regularity got
>> >wiped out by random dating errors.
>> >(2) The one without regularity is correct, in the other one a
>> >regularity arose by chance due to random dating errors.
> > >
>> >The likelyhood of the regularity found with the original GISP2 time
>> >scale occuring by chance is minute - I've done some more
>> >calculations, they are not complete yet but the likelyhood is in the
> > >permil range. I think hypothesis (2) can be exluded at least at 99%
>> >confidence level.
>> >
>> >Stefan
>> >
>> >--
>> >To reach me directly please use: rahmstorfatXYZxyzan-klima.de
>> >(My former addresses @pik-potsdam.de are read by my assistant Brigitta.)
>> >
>> >Stefan Rahmstorf
>> >www.ozean-klima.de
>> >www.realclimate.org
>>
>> --
>> Jonathan T. Overpeck
>> Director, Institute for the Study of Planet Earth
>> Professor, Department of Geosciences
>> Professor, Department of Atmospheric Sciences
>>
>> Mail and Fedex Address:
>>
>> Institute for the Study of Planet Earth
>> 715 N. Park Ave. 2nd Floor
>> University of Arizona
>> Tucson, AZ 85721
>> direct tel: +1 520 622-9065
>> fax: +1 520 792-8795
>> http://www.geo.arizona.edu/
>> http://www.ispe.arizona.edu/
>
>--
>Climate and Environmental Physics, Physics Institute, University of Bern
>Sidlerstr. 5, CH-3012 Bern
>Phone: ++41(0)31 631 44 61 Fax: ++41(0)31 631 87 42
>e-mail: joos@climate.unibe.ch; Internet:
>http://www.climate.unibe.ch/~joos/


--
Jonathan T. Overpeck
Director, Institute for the Study of Planet Earth
Professor, Department of Geosciences
Professor, Department of Atmospheric Sciences

Mail and Fedex Address:

Institute for the Study of Planet Earth
715 N. Park Ave. 2nd Floor
University of Arizona
Tucson, AZ 85721
direct tel: +1 520 622-9065
fax: +1 520 792-8795
http://www.geo.arizona.edu/
http://www.ispe.arizona.edu/
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