cc: mmanning@al.noaa.gov, wg1-ar4-ch06@joss.ucar.edu, Marquis@ucar.edu, v.ramaswamy@noaa.gov, Valerie.Masson@cea.fr, p.m.forster@reading.ac.uk date: Thu, 09 Feb 2006 15:44:34 +0100 from: Renato Spahni subject: Re: [Wg1-ar4-ch06] [Fwd: Greenhouse Gas Figure for IPCC] to: Jonathan Overpeck Content-Type: text/plain; charset=ISO-8859-1; format=flowed X-MIME-Autoconverted: from 8bit to quoted-printable by thunder.joss.ucar.edu id k19H6lC2011714 Dear all, Thank you very much for including me as a contributer to this important report. I changed the EPICA/VOSTOK (CO2 also from Taylor Dome) figure accordingly: - figure with N2O and antropogenic increase - no shaded areas before MIS 11 - isotopes are shown as step plot with highest resolution published ( 0-390kyr: EPICA Community Memebers, 2004; 390-650kyr: Siegenthaler et al. 2005, Spahni et al. 2005) - for visibility reasons the line widths are smaller now - the delta D label has probably a font problem, I converted it as a pdf this time Let me know if I can be of further assistance. All the best, Renato Jonathan Overpeck wrote: > Hi Valerie et al. - let's all weigh in before Renato generates the > final SOD graphic. My thoughts > > 1) I don't feel strongly about the delta D data being smoothed or not > (it makes sense, but will it make a difference? - go ahead if others > agree), but I think we should keep isotopic data, rather than > temperature - to avoid the confusion with the most recent data not > being the warmest - or even close. It's regional temp, I know, but > some readers might realize this. We can say in the caption that delta > D is a regional temp record. I'm just one vote, here... > > 2) I agree with the vert grey shaded areas, and will go one step > farther for a compromise. I vote we keep the shading on the real > interglacials of the last 450kyrs, and delete the grey shading on the > earlier "interglacials" - they are different, clearly, and we can make > that point in the caption. Valerie's reasoning then works the other > way - the grey shading helps readers get the point about how the > length of interglacials comparable to the Holocene have varied, with > MIS 11 being the phattest. > > Thanks, Peck > >> Jonathan Overpeck a écrit : >> >>> Hi Fortunat, Renato and friends: Here's my thoughts on what you have >>> sent wrt to chap 6: >>> >>> 1) for the EPICA/VOSTOK figure, I agree we should go with the >>> version WITH N2O and WITH the anthropogenic increase >>> (ipcc_ghg650kyr_v1ant) Renato - would you please resend with the >>> delta D label fixed. Thanks - otherwise, nice job. >>> >>> >> I have a few comments on the figure ipcc_ghg650kyr_v1ant. >> >> - the deuterium data should be smoothed to appear with a resolution >> similar to the GHG records (we usually use step functions for >> deuterium plots because the measurements are conducted as averages >> for bag samples => not single points). >> >> - it is possible to show temperature fluctuations rather than >> deuterium, if you prefer. >> >> - I am worried about the vertical grey lines on this figure, assumed >> to define "interglacial periods". It is tricky and depends on some >> hypothesis (thresholds on deuterium or GHG). For instance stage 7.5, >> 7.3 should also appear as interglacials with the thresholds used for >> the other warm periods. >> As we are aware of (preliminar) Dome C age scale problems for stages >> 13-15, the grey bars may give false impressions regarding the >> duration of the oldest warm episodes. >> >> Valérie. > > > -- ______________________________ Renato Spahni Climate and Environmental Physics Physics Institute, University of Bern Sidlerstrasse 5 CH-3012 Bern, Switzerland Phone: ++41 (0)31 631 44 76 Fax: ++41 (0)31 631 87 42 spahni@climate.unibe.ch www.climate.unibe.ch/~spahni ______________________________ Attachment Converted: "c:\eudora\attach\ipcc_ghg650kyr.pdf" _______________________________________________ Wg1-ar4-ch06 mailing list Wg1-ar4-ch06@joss.ucar.edu http://www.joss.ucar.edu/mailman/listinfo/wg1-ar4-ch06