From	Jonathan T. Overpeck	Date	Thu, 16 Dec 2004 17:37:03 -0700
To	Ricardo Villalba
CC	Keith Briffa, peltier@atmosp.physics.utoronto.ca, Eystein Jansen
Subject	Re: [Wg1-ar4-ch06] Fw: Section on Modes of Variability
Hi Ricardo - good to hear from you. Thanks too for the interesting figure. I have some comments on this section (6.5.4) and also for the others' you're helping to lead. Regarding 6.5.4 - I hope Dick and Keith will have jump in to help you lead, and I can too. I think the hardest, yet most important part, is to boil the section down to 0.5 pages. In looking over your good outline, sent back on Oct. 17 (my delay is due to fatherdom just after this time), you cover ALOT. The trick may be to decide on the main message and use that to guid what's included and what is left out. For the IPCC, we need to know what is relevant and useful for assessing recent and future climate change. Moreover, we have to have solid data - not inconclusive information. My take: ENSO - coral records sensitive to ENSO (e.g., Urban et al. and Cobb et al - attached) suggest ENSO has changed in response to past forcing change (Cobb et al - updated interp by mann et al - see recent email attachment) and recent climate change (Urban et al). Ditto for Indian Ocean - not sure if can connect to dipole - I could ask Julie Cole? NAO - lots of papers and what's the consensus? I'm not sure, but I think it is that we can't say for sure what has happend to the NAO - or AO for sure (Keith might no more - recent Ed Cook paper might be the key? - I'm not an expert here). Same thing for PDO (not an expert, but aren't their recons that don't agree - see cole et al for one- attached). In both these cases, the recons don't always agree. Or do they say the NAO variability has stayed pretty constant? Tropical Atlantic - Black et al 1999 (attached to prev email) also says 12year mode (no consensus if diapole is the correct name for what Chang first described - see ref in Black attached) has been constant for 800 years. Annual modes - does paleo have anything definitive to say yet? I'm a coauthor on a soon to be submitted AO recon paper, but I'm not sure reviewers will go for it - nor does it match D'Arrigo's recent AO recon paper (can't find). So, the trick is for you to lead us (Dick, Keith, me - maybe Julie - ENSO expert) to produce 0.5 pages of HIGHLY focused and relevant stuff. Can you take another crack at your outline and then tell us what you need? Thanks! Regarding 6.5.9 - can you help Dan, Ramesh and others to make quick headway on this one - it's totally missing. Thanks! Regarding 6.3.2.1 - Keith will need help, no doubt - particularly with a good S. Hemisphere perspective (he can override me on this, but since I'm contacting you...) thanks! What do we have for the southern hem? Southern S. America, New Zealand, Tasmania, ice core? Regarding 6.3.2.2 - what's your opinion of where this section stands? Thanks - hope you are enjoying summer - although Tucson never gets that cold! Best, Peck ----- Original Message ----- From: [1]Ricardo Villalba To: Sent: Thursday, December 16, 2004 2:55 PM Subject: Fw: Section on Modes of Variability Dear IPCC colleagues Please, find attached a preliminary draft of the proposed figure for the section: Modes of variability. The caption follows. Best regards, Modes of variability Figure caption. Coherent modes of climate variability across the Pacific Ocean during the past four centuries. The upper part of this figure compare temperature-sensitive tree-ring records (red triangles) from high-latitude, Western North and South America with a geochemical coral record (yellow triangle) from Raratonga, tropical South Pacific. The series shown from top to bottom are: Spring/Summer Gulf of Alaska temperature reconstruction (1600-1994; Wiles et al., 1998), Sr/Ca coral record from Rarotonga (1726-1996; Linsley et al. 2004) and annual Northern Patagonia temperature reconstruction (1641-1989; Villalba et al., 2003). Correlation coefficients between records are indicated. To facilitate the comparison, the Sr/Ca coral record is shown reversed. Interdecadal to centennial variability in each time series was isolated by using singular spectrum analysis (SSA; lower part of the figure). For each record, all SSA reconstructed components with mean frequencies longer than 20 years where summed. Correlation coefficients between these long-term modes of variability are also shown. Thin and thick arrows indicate coincidences in oscillations between the Raratonga and one or two high-latitude records, respectively. Linsley, B., G. Wellington, D. Schrag, L. Ren, M. Salinger and A. Tudhope, 2004: Geochemical evidence from corals for changes in the amplitude and spatial pattern of South Pacific interdecadal climate variability over the last 300 years. Climate Dynamics, 22, 1-11. Villalba, R., Lara, A., Boninsegna, J.A., Masiokas, M., Delgado, S., Aravena, J.C., Roig, F.A., Schmelter, A., Wolodarsky, A., Ripalta, A. 2003. Large-scale temperature changes across the southern Andes: 20th-century variations in the context of the past 400 years. Climatic Change, 59: 177-232. Wiles, G. C., D'Arrigo, R.D. and Jacoby, G.C., 1998. Gulf of Alaska atmosphere-ocean variability over recent centuries inferred from coastal tree-ring records. Climatic Change, 38, 289-306. Ricardo Ricardo Villalba Departamento de Dendrocronologa e Historia Ambiental IANIGLA - CRICYT C.C. 330, (5500) Mendoza, Argentina Tel: +54 (261) 4287029 ext. 48 Fax: +54 (261) 4285940 e-mail: [2]ricardo@lab.cricyt.edu.ar PAGES SSC: [3]http://www.pages.unibe.ch/ Attachment converted: Macintosh HD:modes of variation.jpg (JPEG/prvw) (000C0BD1) _______________________________________________ Wg1-ar4-ch06 mailing list Wg1-ar4-ch06@joss.ucar.edu http://www.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: "c:\eudora\attach\Cobb2003Nature.pdf" Attachment Converted: "c:\eudora\attach\Cooketal2002GRL.pdf" Attachment Converted: "c:\eudora\attach\Urbanetal00.nature.pdf" Attachment Converted: "c:\eudora\attach\Coleetal2002GRL.pdf" References 1. mailto:ricardo@lab.cricyt.edu.ar 2. mailto:ricardo@lab.cricyt.edu.ar 3. http://www.pages.unibe.ch/