cc: "'Stephen T. Gray'" date: Fri, 17 Oct 2003 13:57:08 -0600 from: "Graumlich, Lisa" subject: RE: help with an idea? to: 'Keith Briffa' , "'cbaisan@ltrr.arizona.edu'" , "'drdendro@ldeo.columbia.edu'" Dear Keith, Chris, and Ed, Keith, thanks for getting this conversation going. I would be happy to contribute the CA data to this effort. I should also mention that my post-doc, Steve Gray, and I have been exploring some similar ideas and are very interested in contributing to a larger project. Attached is our AGU abstract as well as our reconstruction of the AMO. In particular, Figure A shows North Atlantic (0-70N) SST anomalies extracted from the Kaplan et al. 1998 reanalysis data (in SD units). The bottom graph (Fig B) is our tree-ring based reconstruction of SSTA spanning 1567-1990 AD. The black lines represent annual values and the red line shows a 10-yr spline. The data for the reconstruction come from Eastern North America, Europe, Scandinavia and the Middle East. We are combining theses results with our new tree ring data from the inner Mountain West to explore PDO-AMO interactions. It strikes me that we might want to have a conference call, or at least some spirited email, to discuss some ideas for collaboration. With best wishes, Lisa Lisa J. Graumlich Executive Director, Big Sky Institute 406/994-5320 -----Original Message----- From: Keith Briffa [mailto:k.briffa@uea.ac.uk] Sent: Friday, October 17, 2003 8:24 AM To: lisa@montana.edu; cbaisan@ltrr.arizona.edu; drdendro@ldeo.columbia.edu Subject: help with an idea? Hi Lisa and Chris and Ed The first point of this message is to ask for access to the raw data for the Boreal and Camp Hill Foxtail pine chronologies (Lisa) that I believe you and/or your students produced and similar data that you may have (Chris). for the area inland of the Santa Barbara Basin , California. I am also trying to stimulate your interest and hopefully start a joint collaboration (Lisa , Chris and Ed). Please allow me to explain . I was reading some papers on the putative link between North Atlantic temperatures (oxygen isotope record from Greenland) and climate (bio-turbation index) in the Santa Barbara basin , on the 1000-year time scale (papers by Boyle and Leuschner et al. in the PAGES QSR Volume published in 2000). It got me to thinking whether a robust regional temperature chronology for North west Scandinavia might show any associations with any climate factors as represented in either high or low elevation tree-ring chronologies in Western California , at higher temporal resolution (perhaps decades to century) - and hence whether there is any evidence for a thermohaline link (or other more direct dynamic atmospheric connection) operating on various time scales. Of course there are problems with what specific climate response one would investigate (in terms of season and variable). However, as a first look I compared our Tornetrask temperature reconstruction (JJA in Northern Sweden) with a (very) few series I had for the west US - among which were the chronologies mentioned above from AD 800 that Jan Esper and Ed produced for their Science paper, using data supplied by Lisa I believe . Now I don't actually like the general way they applied the RCS ( - using a very large scale standardisation curve based on disparate data from a very wide expanse of sites across the Northern Hemisphere - but as Ed might say " it seems to work "). However, the association between the Tornetrask series and the curves for Boreal/ Upper Wright have stimulated me to try to look deeper and solicit your interest and help. In my opinion, for the 600-year period between AD 1100 and 1700 the similarity in the 5 circa 120-year cycles that make up these series certainly warrant serious further study. The similarity is not apparent before this but the two California series themselves show little agreement in the earlier 300 years of data that I have seen, implying that the common signal at the regional level may not be well represented in either anyway. This could be a standardisation issue though. By producing more robust mean series and especially by extending the series back before the post Christian era we could significantly extend the power of the comparison. I would like to establish well replicated series (using more-local RCS curves based applied to more, and longer, data) for both the Tornetrask (and possibly Northern Finnish) region and the combined set from Upper Wright and Boreal and any other nearby Foxtail data ( from the region of the 118 degrees west 36 degrees north) . We have earlier (than circa AD 800 ) data for Tornetrask and Finland , showing good inter region coherence . If we can establish stronger evidence of a North Atlantic/Eastern Pacific link (at different time scales perhaps) we can look at other high resolution records to establish the nature of the likely forcing and the possible climate dynamic mechanisms. What do you think? Can I play with your data to this end ? Whatever you think , I would appreciate it if you would treat this as confidential and any thoughts on the idea , or pointers to relevant data sets are still welcome. All the very best Keith -- Professor Keith Briffa, Climatic Research Unit University of East Anglia Norwich, NR4 7TJ, U.K. Phone: +44-1603-593909 Fax: +44-1603-507784 http://www.cru.uea.ac.uk/cru/people/briffa/ Attachment Converted: "c:\eudora\attach\AMO recon demo.ppt" Attachment Converted: "c:\eudora\attach\gary AGU Abstract 2003.doc"