date: Wed, 14 May 2003 10:33:03 -0600 from: Tom Wigley subject: Re: paleo & extremes to: Tim Osborn 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 > > >