date: Mon, 22 Jan 2007 14:11:47 +0000 from: Tim Osborn subject: Re: O&B 2006 to: Gerd Bürger Hi again Gerd, regarding the filter settings, I thought the easiest thing was to send you the code I used -- it's in IDL language but probably simple enough to extract the key points even if you aren't familiar with IDL! I used it with "thalf"=20 years. Please don't forward this code on to any one else. Regarding correlations with temperature, we used whatever had previously been published, whether annual or decadal. But for those series (mostly from Esper) for which correlations weren't already published, we calculated our own. For these we used annual resolution, because that is obviously preferable for sample-size reasons. (In most cases, at least, annual time scale is preferable, but if you have a proxy that is not capable of resolving variations on that time scale, it would be unfair to expect it to do so). We could have calculated our own correlations for all the proxies we used, using annual time scale where appropriate. But our main purpose was to try our different analysis method with a similar set of proxies to those used by other studies, rather than to select a very different set of proxies and change the analysis method at the same time. Given that purpose, we accepted previously published correlations as evidence of probably temperature sensitivity of the proxies. Hope that clarifies things, Tim At 08:33 16/01/2007, you wrote: >Tim, > >I can now almost replicate the analysis, except for the exact filter >settings (esp., how many adjacent points for the ends?). > >With respect to proxy selection, why did you choose annual >correlations in some cases and decadal in others, the latter not >being easy to replicate. > >Ciao, > Gerd Attachment Converted: "c:\eudora\attach\filter_cru.pro" 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