cc: wg1-ar4-ch06@joss.ucar.edu date: Fri, 22 Jul 2005 11:59:29 -0600 (MDT) from: Bette Otto-Bliesner subject: Re: [wg1-ar4-ch06] Updated 6.1 (inc. Bette's comments) to: David Rind Looking more closely at the PRISM data set on the web, I would be more comfortable with the following changes and additions to the text: 1. In paragraph 3, temperatures warmer (estimated by GCMs to be 2-3C above preindustrial). The uneven and geographically sparse nature of the data cores makes me uneasy including a global warming estimate based on the data. 2. In paragraph 4, I would like to see numbers (with uncertainties) of high-latitude and tropical warming from the data. This is important since we contend that the Pliocene response is different than what models project for the future. I think in addition to Jim Zachos we should have Alan Haywood look at this box ahay@bas.ac.uk. Bette ______________________________________________ Bette L. Otto-Bliesner Climate Change Research National Center for Atmospheric Research 1850 Table Mesa Drive / P.O. Box 3000 Boulder, Colorado 80307 Phone: 303-497-1723 Fax: 303-497-1348 Email: ottobli@ncar.ucar.edu ______________________________________________ On Fri, 22 Jul 2005, David Rind wrote: > Hi Eyestein, > > Thanks for your comments. With respect to the suggested changes in paragraphs > 1,2 and 4, they seem fine to me. However, I think we need to include in > paragraph 5 potential reasons as to why the substantial (and not just > significant) high latitude warming that appears in the mid-Pliocene record is > not produced in GCMs in response to higher CO2, in general - otherwise we > leave the reader with a big question and no possible solution. The tendency > of GCM simulations for the future climate to produce an NADW decrease forces > those simulations to have minimal high latitude warming in the North > Atlantic, exactly opposite the inference from the Pliocene paleo-record > (which is quite robust in this respect at least). If the Pliocene record is > indicating the opposite of what current models are predicting, it may be > offering us a valuable clue... > > The suggested reasons also include the comment that the lack of land ice at > high northern latitudes might be a strong contributing cause - which would > make it a no-analog situation, and hence not fully a GCM problem. > > I would favor leaving those two sentences as they were. > > David > > > At 5:19 PM +0200 7/22/05, Eystein Jansen wrote: >> Hi, >> see enclosed some comments to the last version of the deep time box. I >> propose some deletions and some toning down of language. What do you think? >> >> Eystein >> -- >> ______________________________________________________________ >> Eystein Jansen >> Professor/Director >> Bjerknes Centre for Climate Research and >> Dep. of Earth Science, Univ. of Bergen >> Allégaten 55 >> N-5007 Bergen >> NORWAY >> e-mail: eystein.jansen@geo.uib.no >> Phone: +47-55-583491 - Home: +47-55-910661 >> Fax: +47-55-584330 >> >> Attachment converted: Toltec:IPCC Box 6.1_latest_EJcomm.doc (WDBN/«IC») >> (1BE54183) > > > -- > /////////////////////////////////////////////////////////////////////////// > > /////////////////////////////////////////////////////////////////////////// > _______________________________________________ Wg1-ar4-ch06 mailing list Wg1-ar4-ch06@joss.ucar.edu http://www.joss.ucar.edu/mailman/listinfo/wg1-ar4-ch06