cc: k.briffa@uea.ac.uk date: Mon, 8 Apr 2002 07:55:05 -0400 from: Edward Cook subject: Re: Fwd: RE: Recent NH reconstruction to: Tim Osborn Hi Tim, Some quick questions, comments, and a request. First, when you say that you recalibrated all of the series shown in your windy perspectives bit, what time period did you recalibrate all the series over? Was it the same for all series? Just to be clear here, I thoroughly dislike the pre-1900 instrumental data. That pre-1900 warming back to 1860 or so is very suspicious. No large-scale pure proxy estimates have ever been able to reproduce it. Only the MBH series does because it includes instrumental data. Thus, recalibrating the proxies using pre-1900 observed data may be biasing the results. That is why I did not use the pre-1900 data in my calibration. Phil would probably disagree strongly with me here, perhaps you and Keith too, but that is my opinion. Also, how did you express all series as anomalies from the observed 1961-1990 mean when not all series extended out to 1990 (e.g. Briffa1, Mann)? I honestly dislike such short anomaly periods in any case, especially when the data are trendy. It unnaturally distorts the visual expression of the data (my opinion anyway). Finally, can you send me the unfiltered observed land-only data that you used? Cheers, Ed -- ================================= Dr. Edward R. Cook Doherty Senior Scholar Tree-Ring Laboratory Lamont-Doherty Earth Observatory Palisades, New York 10964 USA Phone: 1-845-365-8618 Fax: 1-845-365-8152 Email: drdendro@ldeo.columbia.edu =================================