cc: joos , Eystein Jansen , Keith Briffa date: Mon, 17 Jul 2006 21:23:31 -0600 from: Jonathan Overpeck subject: Re: new fig 6.14 to: Tim Osborn Hi Tim (and Fortunat especially) - this is looking nice. I agree that the MOST important thing is for Fortunat to check to make sure everything is calculated/plotted as it should be. After that, here's my feedback... 1) I agree option 1 is much preferred, with the caveat that it would be good to see a version with raw annual volc histogram spikes underneath the smoothed volcanic forcing. The reason is that the CLAs of the TS want them, and I agree it helps demonstrate even more that we know a great deal about forced climate variability prior to the last century. Can you pls make such a version for us to check? 2) for the color bar showing shades of grey, I think the goal is to have the same grey scaling in ALL of the figs (the revised 6.10, the revised 6.13 [same as old, minus panel e], and the new 6.14). This means no more red shading in 6.10. In all of these, it was suggested (and we agreed in Bergen) that the grey scale bar have about half as many intervals labeled - only label intervals of 10 rather than 5. Next... yes, it would be good to have the grey scale bar in each of the figs, but we can save in the captions by referring back to the 6.10 caption, since they'll all be the same now. OK? 3) ok to plot for only the last 1000 years 4) colors seem ok - suggest you add another color to the smoothed volcanic once it's superimposed on the annual peaks. So, please bing Fortunat until you know you have his blessing - the recent solar is strange, was it really supposed to be flat post 1961. Should we try to update the model runs? (Question is for Fotunat) Thanks! Peck >Hi Peck, Eystein and Fortunat, > >I've drafted two versions of the new fig 6.14, >comprising a new panel showing the forcing used >in the EMIC runs, plus the old fig 6.13e panel >showing the EMIC simulated NH temperatures. >Keith has seen them already. > >First you should know what I did, so that you >(especially Fortunat) can check that what I did >was appropriate: > >(1) For the volcanic forcing, I simply took the >volcanic RF forcing from Fortunat's file and >applied the 30-year smoothing before plotting it. > >(2) For the solar forcing there are 2 curves. >For the first, I took the Bard 0.25% column from >Fortunat's RF file. For the second, I took the >Bard 0.08% column from Fortunat's RF file from >1001 to 1609, and then appended the WLS RF >forcing from 1610 to 1998. Then I smoothed the >combined record. NOTE that for the Bard0.25%, >the line is flat from 1961 onwards which >probably isn't realistic, even though that is >what was used in the model runs. > >(3) For the "all other forcings" there are 2 >curves. For the first, I took the CO2 >concentrations provided by Fortunat, then used >the "standard" IPCC formula from the TAR (in >fact the first of the three options for CO2 in >IPCC TAR Table 6.2) to convert this to a >radiative forcing. I then added this to the >non-CO2 radiative forcings data from Fortunat's >file, to get the total radiative forcing. For >the second, I replaced all values after 1765 >with the 1765 value (for the natural forcings >case). Then I smoothed the combined record (as >in fig 6.13c, I only applied a 10-year smoothing >when plotting the "all other forcings", because >it is fairly smooth anyway and using a high >smoothing results in lower final values when >there is a strong trend at the end of a time >series). > >Now, some comments on the figures themselves >(please print them and refer to them when >reading this): > >(1) File 'chap6_f6.14_option1.pdf' is strongly >preferred by Keith and me. This shows the three >forcing components separately, which helps with >understanding the individual causes of specific >warming and cooling periods. I have managed to >reduce the size of this considerably, compared >to the equivalent panel in fig 6.13, because >with only a few series on it I could squeeze >them together more and also reduce the range of >the vertical axes. > >(2) Although we don't prefer it, I have also >made 'chap6_f6.14_option2.pdf' which is even >smaller by only showing the sum of all the >forcings in the top panel. > >Which version do you prefer? Please let me know >so I can make final changes only to the >preferred version. > >Some more comments: > >(1) Fig 6.14b was originally Fig 6.13e. When it >was part of that figure, the colour bar showing >the shades of grey used to depict the >overlapping ranges of the published temperature >reconstructions was only on Fig 6.13d. Do you >think I should now also add it to the EMIC panel >(6.14b), now that it is in a separate figure? >It will be a bit of a squeeze because of the >legend that is already in 6.14b. > >(2) Another carry over from when 6.14b was part >of 6.13, is that the time range of all panels >had to match (900-2010). Now that the EMICs are >in a separate figure, I could start them in year >1000, which is when the forcing and simulations >begin. Unless you want 6.13 and 6.14 to remain >comparable? Again please comment/decide. > >(3) I wasn't sure what colours to use for the >forcing series. In option 1, the volcanic and >other forcings apply to all runs, so I chose >black (with thick/thin used to distinguish the >"all" forcings from the "natural-only" forcings >(basically the thin flat line in "all other >forcings). The cyan-green-blue runs used strong >solar forcing, so I used blue for that forcing. >The red-orange-brown runs used weak solar >forcing, so I used brown for that forcing. >Sound ok? > >Sorry for the long email, but I wanted to get >everything explained to avoid too many >iterations. > >Please let me know your decisions/comments on >these questions, or on any other aspects of the >new figure. > >Cheers > >Tim > > >Attachment converted: Macintosh >HD:chap6_f6.14_option1.pdf (PDF /«IC») (00141908) >Attachment converted: Macintosh >HD:chap6_f6.14_option2.pdf (PDF /«IC») (0014190F) >Dr Timothy J Osborn, Academic Fellow >Climatic Research Unit >School of Environmental Sciences, University of East Anglia >Norwich NR4 7TJ, UK > >e-mail: t.osborn@uea.ac.uk >phone: +44 1603 592089 >fax: +44 1603 507784 >web: http://www.cru.uea.ac.uk/~timo/ >sunclock: http://www.cru.uea.ac.uk/~timo/sunclock.htm > >**Norwich -- City for Science: >**Hosting the BA Festival 2-9 September 2006 -- Jonathan T. Overpeck Director, Institute for the Study of Planet Earth Professor, Department of Geosciences Professor, Department of Atmospheric Sciences Mail and Fedex Address: Institute for the Study of Planet Earth 715 N. Park Ave. 2nd Floor University of Arizona Tucson, AZ 85721 direct tel: +1 520 622-9065 fax: +1 520 792-8795 http://www.geo.arizona.edu/ http://www.ispe.arizona.edu/