date: Wed, 14 May 2003 10:33:03 -0600
from: Tom Wigley <wigley@ucar.edu>
subject: Re: paleo & extremes
to: Tim Osborn <t.osborn@uea.ac.uk>

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Tim,

Thanx. I will keep in touch on the paleo stuff. Comparisons of results 
is a good first goal. Different forcings and different climate 
sensitivities present a bit of a challenge, but I think we can get 
around that using MAGICC.

Tom.
++++++++++++++++++++++++++++++++++++++++++++

Tim Osborn wrote:
> Hi Tom,
> 
> (1) the extremes reference in question appeared last year:
> 
> Extreme daily precipitation in Western Europe with climate change at 
> appropriate spatial scales
> M. J. Booij
> Department of Civil Engineering, University of Twente, PO Box 217, 7500 
> AE Enschede, The Netherlands
> email: M. J. Booij (m.j.booij@sms.utwente.nl)
> 
> International Journal of Climatology
> Volume 22, Issue 1, 2002. Pages: 69-85
> 
> I'm not sure which other references you would be particularly wanting - 
> obviously this is a big subject area.  We have a useful list of some of 
> them on one of our webpages:
> http://www.cru.uea.ac.uk/projects/mice/html/extremes.html#references
> 
> Also see these (need to make your font pretty big to read these!):
> http://www.met.rdg.ac.uk/~han/Extremes/bib0.html
> http://www.met.rdg.ac.uk/~han/Extremes/bib1.html
> 
> (2) HadCM3 run for 1500-2000 under natural only forcings is complete.  
> 1750-2000 under "all" forcings is almost complete (its into the 20th 
> century).  I did email Caspar in January asking whether there is 
> interest in comparisons across the models (we also have 
> ECHAM4/HOPE[==ECHO-G] runs in our EU project SO&P), but I didn't get a 
> response.  Multi-model comparisons might be interesting to do still 
> (though SO&P partners were keen to keep the initial focus within our 
> project just on HadCM3 and ECHO-G).  Is that why you were asking, 
> because of possible comparisons that might be made?  As to the forcings, 
> I agree that the volcanic forcings used could be better, but we were to 
> some extent constrained by our wish to have very similar forcings in 
> HadCM3 and ECHO-G and the ECHO-G runs were begun about 2 years ago I 
> think!  The solar forcing is also of concern - did you use the Lean et 
> al. estimates for that?  While there are clearly some big uncertainties, 
> from what I understand there is qualitative (at least) agreement with 
> 14C and 10Be records.  Presumably MAGICC (or similar) could help to 
> quantify the global/hemispheric scale differences due to forcing 
> uncertainties?  I'm keen to keep collaborative links open on these 
> issues (though subject to agreement with my SO&P partners, of course), 
> so if you have any specific analyses/comparisons that we could work on 
> together (or involving Sarah) then let me know.
> 
> Cheers
> 
> Tim
> 
> At 21:18 13/05/2003, you wrote:
> 
>> Tim,
>>
>> I thought you might be able to tell me how the Hadley paleo runs are 
>> going. We (Caspar Ammann et al.) have completed a run from 1000AD to 
>> the present using the paleo version of CSM (slightly poorer resolution 
>> that the standard CSM). The results are quite interesting. I believe 
>> we are using a better volcano record (Caspar's) than anyone else. 
>> Solar is tricky -- the astronomical basis for Judith Lean's low 
>> frequency irradiance reconstruction has been shot down as you probably 
>> know.
>>
>> One of the nice results is that we can use MAGICC to back out the 
>> signal from the noise. Sarah has some material that I sent her showing 
>> that MAGICC can simulate both volcanic responses (on a monthly to 
>> century time scale) and solar responses (annual to century) with 
>> extremely high fidelity. Ask her to show you.
>>
>> On another matter, you showed me a paper some time back on extreme 
>> value distributions, which I think you were refereeing. There was an 
>> earlier paper on the same subject by the same author. Can you give me 
>> the references -- and any other relevant items dealing with the 
>> modeling of changes in the frequency of extremes?
>>
>> Best wishes,
>> Tom.
> 
> 
> Dr Timothy J Osborn                 | phone:    +44 1603 592089
> Senior Research Associate           | fax:      +44 1603 507784
> Climatic Research Unit              | e-mail:   t.osborn@uea.ac.uk
> School of Environmental Sciences    | web-site:
> University of East Anglia __________|   http://www.cru.uea.ac.uk/~timo/
> Norwich  NR4 7TJ         | sunclock:
> UK                       |   http://www.cru.uea.ac.uk/~timo/sunclock.htm
> 
> 
> 


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