cc: Olga Solomina , Keith Briffa , Ricardo Villalba , ValÈrie Masson-Delmotte , Oyvind.Paasche@bjerknes.uib.no date: Mon, 31 Jul 2006 09:52:02 +0200 from: Eystein Jansen subject: Re: Thompson et al, 2006 paper to include to: Valerie.Masson@cea.fr, Jonathan Overpeck Hi Olga, I agree with Valerie that the ice core evidence is ambiguous. I would personally place more weight on the alkenone data, which is a reasonable well calibrated SST proxy. Foraminifer transfer function based SSTs and some Mg/Ca results that are available suggest a similar picture as far as I know. Of course it is possible and plausible that the tropical oceans are behaving in a non consistent manner and not all areas are showing the same signal, but a sizeable portion appear to do so in order to conclude as we do in the chapter in my opinion. Some signals may be due to changes in in trade wind induced coastal upwelling strength, but there are enough cores with alkenone data outside of these areas. If we were to say more about the uncertainties it may be the fact that proxies are seasonally skewed. My conclusion is to let the chapter say what we say at the moment. Cheers, Eystein At 09:42 +0200 31-07-06, Valérie Masson-Delmotte wrote: >Thanks Olga. > >It seems to me that there is still a large >uncertainty about the temperature versus >precipitation effect on these tropical glaciers. >Other indications from south America are related >to lake levels with contrasted views in the low >versus highlands. >Several references suggest that there is the end >of a wet period after the early Holocene in >tropical south America ; this is expected to >induce an increase of 18O signals. >One review was conducted several years ago >within the PEPI project >(http://wwwpaztcn.wr.usgs.gov/pcaw/ and >references herein). >I think that the state of the art is that we >have no reliable proxy record that is sensivite >to temperature only on the tropical lands for >the Holocene; therefore the statement that was >written for the Holocene was based on areas of >the tropical oceans where SST reconstructions >were published. >Do we have to write more explicitely about the uncertainty? > >Valérie. > >Jonathan Overpeck a écrit : >>Hi Olga - it is not too late to ask these good >>questions. Glaciers can, of course, be affected >>by both temp and precip changes, so the >>question is really for Valerie (land) and >>Eystein (ocean) - are the land and ocean data >>from the tropics strong enough to outweigh what >>the glaciers are saying about tropical temps >>earlier in the Holocene? Lonnie's Figure 8 >>(see attached) presents Hauscaran and >>Kilimanjaro data that suggest early to mid >>warmth in tropical South America and Africa >>that is (if the O-isotopes are temp) greater >>than today. Personally, I'm quite unsure that >>these are reliable temperature records, BUT if >>we want to make that case, we have to be >>convincing. What do terrestrial and ocean temp >>data say? >> >>Thanks Olga for sending the proposed revised >>text - I think Eystein is putting finishing >>touches on the next draft for LA etc. review. >> >>Best, Peck >> >>>¤ >>>Hello everybody, >>> I attach here a version of glacier box and >>>suggestions (in red) how to include there the >>>reference to the new Thompson et al., 2006 >>>paper. >>> In this relation - I am getting more and more >>>concern about our statement that the Early >>>Holocene was cool in the tropics - this paper >>>shows that it was, actually, warm - ice core >>>evidences+glaciers were smaller than now in >>>the tropical Andes. The glaciers in the >>>Southern Hemisphere (Porter, 2000, review >>>paper) were also smaller than at least in the >>>Neoglacial. We do not cite Porter's paper for >>>the reason that we actually do not know how to >>>explain this - orbital reason does not work >>>for the SH, but if we do cite it (which is >>>fair) we have to say that during the Early to >>>Mid Holocene glaciers were smaller than later >>>in both Northen, and Southern Hemisphere, >>>including the tropics, which would contradict >>>to our statement in the Holocene chapter and >>>the bullet. It is probably too late to rise >>>these questions, but still just to draw your >>>attention. >>> I am going to Kamchatka tomorrow, but will be >>>avaliable by e-mail from time to time. >>> All the best, >>>olga >>> >>> ----- Original Message ----- >>> >>> *From:* Jonathan Overpeck >>> >>> *To:* Olga Solomina >>> >>> *Cc:* Eystein Jansen ; >>> oyvind.paasche@bjerknes.uib.no >>> >>> >>> *Sent:* Sunday, July 30, 2006 3:42 AM >>> >>> *Subject:* Re: [Wg1-ar4-ch06] Fwd: Additional In-Press Papers >>> >>> >>> Hi Olga - I agree, and hope that you and òyvind make sure you >>> include it in the next round of edits, which will begin very >>> soon. We have all of the new text and Eystein is assembling for >>> authors to check. This same new draft will be the one that >>> Eystein and I work on to achieve more consistency and the proper >>> length. Although we've cut some text already, some received has >>> grown too. So... think about a way to include the reference to >>> Lonnie's work without lengthening if you can. >>> >>> >>> OK? Many thanks, Peck >>> >>>> Hi Peck, >>> >>> >>> >>> Lonnie's paper is a very good one and suitable for the >>> glacier box. If it is still possible I would add this reference. >>> >>> >>> >>> olga >>> >>> ----- Original Message ----- >>> >>> *From:* Jonathan Overpeck >>> >>> *To:* wg1-ar4-ch06@joss.ucar.edu >>> >>> >>> *Sent:* Friday, July 28, 2006 6:32 PM >>> >>> *Subject:* [Wg1-ar4-ch06] Fwd: Additional In-Press Papers >>> >>> >>> Hi Chap 6 LA's - here is another batch of papers from the >>> TSU to be considered using the guidelines provided below >>> - we don't want to add citations just to make our ref >>> list more complete. >>> >>> Thanks, Peck and Eystein >>> >>>> X-Sieve: CMU Sieve 2.2 >>>> Date: Wed, 26 Jul 2006 11:25:25 -0600 >>>> From: IPCC-WG1 >>> > >>>> X-Accept-Language: en-us, en >>> >>> To: Jonathan Overpeck , >>> Eystein Jansen >>> Subject: Additional In-Press Papers >>> >>> Dear CLAs >>> >>> Please find attached additional paper(s) that are >>> relevant to your chapter and have been submitted in >>> response to our most recent guidelines for >>> consideration of papers published in 2006 following >>> the expert and government review. A separate >>> spreadsheet file is attached listing: the submitter, >>> file name of the paper, its acceptance date, and the >>> chapter and section which the submitter feels is >>> relevant. >>> >>> As discussed in Bergen, please note the following: >>> * inclusion of additional papers in the final draft >>> should not open up any substantive issues that were >>> not in the second draft and so not previously reviewed; >>> * additional papers should only be used where in the >>> view of the LAs doing so provides a more balanced >>> coverage of scientific views; >>> * we anticipate that a quick reading of the abstract >>> of each paper will enable a decision consistent with >>> this and we would not encourage any lengthy >>> consideration by the LA team. >>> >>> One additional point to keep in mind is that this >>> most recent adjustment of our publication deadlines >>> should not be perceived by others as a device for >>> allowing the LAs to reference more of their own >>> papers. We trust that you and your team will be both >>> objective and vigilant when deciding to include or >>> reject papers in this respect. >>> >>> Best regards, >>> WG1 TSU >>> >>> -- >>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >>> IPCC WGI TSU >>> NOAA Chemical Sciences Division >>> 325 Broadway DSRC CSD08 >>> Boulder, CO 80305, USA >>> Phone: +1 303 497 7072 >>> Fax: +1 303 497 5686/5628 >>> Email: ipcc-wg1@al.noaa.gov >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> -- >>> >>> 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/ >>> >>> >>>------------------------------------------------------------------------ >>> >>> _______________________________________________ >>> Wg1-ar4-ch06 mailing list >>> Wg1-ar4-ch06@joss.ucar.edu >>> http://lists.joss.ucar.edu/mailman/listinfo/wg1-ar4-ch06 >>> >>> >>> >>> -- >>> >>> 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/ >>> >>> >>>Attachment converted: Macintosh HD:Glaciers 30 >>>july so.doc (WDBN/«IC») (00148B9A) >> >> >>-- >> 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/ -- ______________________________________________________________ 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