In today’s post, I’m going to discuss an important new 1000-year chronology from northern treeline spruce in Quebec (Gennaretti et al 2014, PNAS here). The chronology is interesting on multiple counts. This is the first Quebec northern treeline chronology to include the medieval warm period. Second, it provides a long overdue crosscheck against the Jacoby-D’Arrigo chronologies (including […]
8 new tree ring measurement data sets have archived this week at WDCP in northern Alberta by Meko. The sites are around 58N, 111W , well to the northeast of the Jasper site (52N, 117W) which is used in nearly all the multiproxy studies. I did a “standard” type chronology fitting negative exponential curves by […]
D’Arrigo et al. [GRL 2004] reports on tree rings taken from the Seward Peninsula in northwestern Alaska from white spruce from 14 sites near elevational treeline in summer 2002. We show here their figures, demonstrating that the "proxy" show no evidence of the warm 1990s and hot 1998, raising questions about the ability of this […]
The PAGES (2017) North American network consists entirely of tree rings. Climate Audit readers will recall the unique role of North American stripbark bristlecone chronologies in Mann et al 1998 and Mann et al 2008 (and in the majority of IPCC multiproxy reconstructions). In today’s post, I’ll parse the PAGES2K North American tree ring networks […]
See here http://science.house.gov/hearing/full-committee-hearing-climate-change Webcast Witnesses Dr. J. Scott Armstrong, Professor, The Wharton School, University of Pennsylvania Dr. Richard Muller, Professor, University of California, Berkley and Faculty Senior Scientist, Lawrence Berkeley Laboratory Dr. John Christy, Director, Earth System Science Center, University of Alabama in Huntsville Mr. Peter Glaser, Partner, Troutman Sanders, LLP. Dr. David Montgomery, Economist […]
ABSTRACT: A new method is proposed for determining if a group of datasets contain a signal in common. The method, which I call Correlation Distribution Analysis (CDA), is shown to be able to detect common signals down to a signal:noise ratio of 1:10. In addition, the method reveals how much of the common signal is […]
I’m finding some benefit to having spent some time on station histories prior to my present re-visit to Mannian proxies. Digging into the handling of station histories gives some interesting perspectives on network handling that are worth considering for tree ring networks. For example, assume for a moment that North American tree ring chronologies used […]
I’ve already received my first condescending comments from the dendro world about the mysteries of standardization. Just to pre-empt some further pontification presuming that I know nothing about these mysteries, I’m posting up some notes that I wrote in 2004 on standardization – which was what I would have been working on had people just […]
Many Americans of a certain age will recall an American radio commentator, called Paul Harvey, who ran ironic commentaries entitled "The End of the Story". They were short segments leading you to expect one answer and Harvey’s closing comment explaining what happened would reverse the field altogether. I once heard a commentary on dendrochronology, in […]
Here is Lamarche’s diagram of altitudes at the key bristlecone sites of Sheep Mountain and Campito Mountain (as noted below, when wood erosion is allosed for, the post-MWP decline is placed after 1500.)
