Monthly Archives: November 2023

MBH98 Weights – an Update

Nov 26, 2023 – 2:10 PM

In numerous ancient Climate Audit posts, I observed that all MBH98 operations were linear and that the step reconstructions were therefore linear combinations of proxies, the coefficients of which could be calculated directly from the matrix algebra (described in a series of articles.)   Soderqvist’s identification of the actual proxies enables calculation of the AD1400 weights […]

By Stephen McIntyre | Posted in Uncategorized | Tagged , , | Comments (58)

Mann’s Other Nature Trick

Nov 24, 2023 – 2:51 PM

In today’s post, I will report on some excellent work on MBH98 by Hampus Soderqvist, who discovered an important but previously unknown Mike’s Nature Trick: Mann’s list of proxies  for AD1400 and other early steps was partly incorrect (Nature link now dead – but see  NOAA or here).  Mann’s AD1400 list included four series that […]

By Stephen McIntyre | Posted in Uncategorized | Tagged , , | Comments (52)

MBH98 Confidence Intervals

Nov 10, 2023 – 10:55 AM

Continued from here. The Dirty Laundry residual datasets for AD1000, AD1400 and AD1600 were each calculated using Mann’s “sparse” instrumental dataset, but the resultant sigmas and RE(calibration) statistics don’t match reported values.   In contrast, the Dirty Laundry residual dataset for the AD1820 step, which was calculated by Tim Osborn of CRU because Mann “couldn’t find” […]

By Stephen McIntyre | Posted in Uncategorized | Tagged , , , | Comments (6)

“Dirty Laundry” Residuals

Nov 8, 2023 – 8:31 AM

Continued from previous post link. The data associated with the Climategate “dirty laundry” email had other interesting information on Mann’s calculation of confidence intervals and the related calculation of RE statistic.  This post draws heavily on offline comments by Jean S and UC, both long before and after Climategate. The left panel below is Tim Osborn’s […]

By Stephen McIntyre | Posted in Uncategorized | Comments (5)

Mann’s “Dirty Laundry”

Nov 7, 2023 – 2:26 PM

As the date approached for the Mann-Steyn/Simberg libel trial, I’ve been reviewing my files on MBH98 and MBH99. It’s about 15 years since I last looked at these issues.  While revisiting these issues, I re-examined some data associated with the notorious “dirty laundry” Climategate email (link)  – excerpt shown at right – that turns out […]

By Stephen McIntyre | Posted in Uncategorized | Tagged , , , , | Comments (21)