Sunday, June 3, 2012

4858.txt

cc: Olga Solomina <solominaatXYZxyz.ru>, Peter Lemke <plemkeatXYZxyz-bremerhaven.de>, jtoatXYZxyzrizona.edu
date: Mon, 27 Feb 2006 18:09:24 +0100 (MET)
from: Georg Kaser <Georg.KaseratXYZxyzk.ac.at>
subject: Re: IPCC Ch4.5
to: Keith Briffa <k.briffaatXYZxyz.ac.uk>

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Dear Keith,

have many thanks. I am glad you can keep this. The paragraph looks fine
for me although we had some comments on the Vincent findings saying:

"I am not sure I agree with this statement. Vincent et al. (2005, cited in
the chapter) guess a 25% precipitation increase in the 1760-1830 period
compared to the 20th century average and this is based on a simple model
(degree-days) to explain glaciers extent. However, Casty et al.
(Temperature and precipitation variabiltiy in the european Alps since
1500, Int. J. Climatology, in press) find no such precipitation increase
in the observations.The 2 results are thus in conflict. [Christophe
GENTHON]"

Does anyone know the Casty paper? Valerie may have an insight to this
Inner French discussion. Sorry that I had not forwarded this to you
earlier.

Regards,
Georg

Georg Kaser
-------------------------------------------------
Institut fuer Geographie
Innrain 52
A-6020 INNSBRUCK
AUSTRIA
Tel: ++43 512 507 5407
Fax: ++43 512 507 2895
http://meteo9.uibk.ac.at/IceClim/CRYO/cryo_a.html

On Mon, 27 Feb 2006, Keith Briffa wrote:

> Georg
> we have included the Oerlamans curve and modified a piece of text from your
> original text . that is
>
> Oerlemanns (2005) has constructed a temperature history for the globe based
> on 169 glacier-length records. He uses simplified glacier dynamics that
> incorporate specific response time and climate sensitivity estimates for each
> glacier. The reconstruction suggests that moderate global warming occurred
> after the middle of the 19th century, with about 0.6 degree C warming by the
> middle of the 20th century. Following a 25-year cooling, temperatures rose
> again after 1970, though much regional and high-frequency variability is
> superimposed on this overall interpretation. However, this approach does not
> allow for changing glacier sensitivity over time, which may limit the
> information before 1900. Analyses of glacier mass balances, volume changes,
> and length variations along with temperature records in the western European
> Alps (Vincent et al., 2005) indicate that between 1760 and 1830, glacier
> advance was driven by precipitation that was 25% above the 20th century
> average ,while there was little difference in average temperatures. Glacier
> retreat after 1830 was related to reduced winter precipitation and the
> influence of summer warming only became effective at the beginning of the
> 20th century. In southern Norway, early 18th century glacier advances can be
> attributed to increased winter precipitation rather than cold temperatures
> (Nesje and Dahl, 2003).
>
> For now this is all we can manage and we are discussing the need to cut our
> Chapter further - but this will at least remain
> thanks
> Keith
>
> At 16:16 27/02/2006, Georg Kaser wrote:
>> Dear Olga and Keith,
>>
>> find attached the present state of chapter 4.5 on glaciers and ice caps. We
>> have now entirely removed the MWP and LIA discussion and I hope you have
>> been able to cover this. I also hope that you have been able to implement
>> the Oerlemans temperature curve as we had agreed. If I have missed to
>> supply you with anything I should have, please apologize and let me know.
>>
>> With best wishes,
>> Georg
>>
>> Georg Kaser
>> -------------------------------------------------
>> Institut fuer Geographie
>> Innrain 52
>> A-6020 INNSBRUCK
>> AUSTRIA
>> Tel: ++43 512 507 5407
>> Fax: ++43 512 507 2895
>> http://meteo9.uibk.ac.at/IceClim/CRYO/cryo_a.html
>>
>
> --
> Professor Keith Briffa,
> Climatic Research Unit
> University of East Anglia
> Norwich, NR4 7TJ, U.K.
>
> Phone: +44-1603-593909
> Fax: +44-1603-507784
>
> http://www.cru.uea.ac.uk/cru/people/briffa/
>
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