As a mindless activity, I’ve re-visited the Crowley data, which we’re discussing. Among other stereotypes, out of 15 series, Crowley uses 2 bristlecones, Polar Urals, Tornetrask and Dunde. Even so, without any grafting, there’s not much hockey-stick-ness to this dataset. When you parse Crowley, you also see some very odd decisions, which result in lowering […]
I’ve been re-visiting the various multiproxy studies with respect to scale and variability. In addition, as you know, one of my interests in these multiproxy studies is the non-robustness of MWP-modern levels to a very few non-independent proxies, used in multiple studies – in particular: bristlecones, Polar Urals and Thompson’s Himalayan dO18 series – each […]
I never quite got to presenting an attempt to replicate Moberg before. Here’s a try. I’m still a long way off from being able to replicate his results. It is so infuriating to have to try to do such an amount of detective work prior to even atempting any analysis. I presume that has been […]
Yesterday I waded through a demonstration of a fairly egregious splice of the instrumental record into Crowley’s reconstruction as used in Crowley [2000]. Today I consider the use of the Crowley reconstruction in spaghetti graphs and, in particular, Mann’s statement at realclimate that: No researchers in this field have ever, to our knowledge, "grafted the […]
Update: See continued discussion here. I’m working up some material for the AGU convention and re-visited some points in Crowley and Lowery [2000] which I’d not been able to figure out before. (One of Bruce McCullough’s strongest arguments for providing source code is that it reduces the cost of replication studies, since the replicator does […]
A couple of months ago, after getting nowhere with Moberg on same peculiarities in some data sets (see right category Moberg et al ), I filed a Materials Complaint to Nature discussed here. There have been some developments on this. Readers may recall that, on a previous occasion, in connection with MBH98, Ross and I […]
Jones et al. [1998] makes the reasonable policy that proxies should be validated against gridcell temperatures as evidence that they are temperature proxies, noting that this is not always done. This policy is endorsed in Jones and Mann [2004], who note that not all multiproxy studies had observed this policy, presumably including MBH98, which included […]
I mentioned here that I would be presenting at a poster session at the U.S. Climate Change Workshop (Nov 14 evening, Crystal Gateway Marriott, Arlington Virginia). Poster pdf’s are supposed to be in tomorrow. Here’s a draft. I’d appreciate any comments. Obviously many of the points are ones that readers of this blog are familiar […]
Here is some interesting information from an Oman speleothem is a proxy for Indian Ocean monsoon levels. One of the most influential proxies in Moberg [2005] is Oman coldwater diatoms and there is a connection. It may also shed some light on Himalaya ice cores, which also measure dO18 in monsoone precitation.
The first step in the J98 procedure is the standardization of all series based on 1901-1950 and then taking an average. I’m not a big fan of short-period standard deviations (not just me, but see also Trenberth [1984]). All of these series are at least 300 years long, so there’s no need for 50-year standard […]
Climate Audit 