In today’s post, I’m going to critically examine another widely used tree ring chronology: the Icefields (Alberta) MXD RCS chronology of Luckman and Wilson (2005 pdf), used most recently in Wilson et al 2016. I’ll show that the RCS technique used in the LW2005 MXD chronology eliminated high medieval values as a tautology of their method, not […]
Last week, I posted on the effect of ex post site selection on the Gulf of Alaska tree ring chronology used in Wilson et al 2016 (from Wiles et al 2014). An earlier incarnation of this chronology (in D’Arrigo et al 2016) had had a severe divergence problem, a problem that Wiles et al had purported to […]
Wilson et al 2016, like D’Arrigo et al 2006, includes a ‘Polar Urals’ chronology as one of its components. Tree ring chronologies from Polar Urals and Yamal have long been a contentious issue at Climate Audit, dating back to the earliest days (see tags Yamal, Polar Urals). Whereas the D’Arrigo et al 2006 version had one […]
Starting with the first of my recent posts on Yamal, I raised the issue of whether the CRU 12 actually came from a homogeneous population to the subfossil population. Although Briffa’s online response to my Yamal posts stated that CRU has “stressed” potential problems arising from “inhomogeneous” sources” in their “published work”, I have been […]
Starting with the first of my recent posts on Yamal, I raised the issue of whether the CRU 12 actually came from a homogeneous population to the subfossil population. This issue was related to the surprisingly small sample size of the supposedly “highly replicated” Yamal chronology, but is distinct. In his online response to Yamal […]
In examining the Briffa Yamal chronology, there has been a lot of emphasis (IMHO, correctly) placed on both the cherry-picking and the low core counts of the proxies which extend into recent times. However, the chronology also depends on the various methods used to adjust for various known biological effects and on the choices for […]
Obviously, there has been considerable controversy over the past few days over the Yamal data. First, let’s observe the continued silence of field dendros on the dispute. None have stepped forward so far to support Briffa’s use of 10 cores in 1990 (and 5 in 1995). As others have observed, their silence is rapidly becoming […]
One reader asked whether my RCS results held up using “standard” software. There is no “standard” software for RCS. It is different than ARSTAN. Further, despite the use of Briffa’s RCS chronologies in many multiproxy studies, until the present data sets were archived, to my knowledge, there were no public examples where both a measurement […]
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