Sometimes the Hockey Team baffles me. I was at Esper’s website and noticed Esper J, Neuwirth B, Treydte K (2001) A new parameter to evaluate temporal signal strength of tree ring chronologies. Dendrochronologia 19, 93-102. Something that looked pertinent. As a component of his estimate of signal strength, Esper applied a statistical procedure Gleichlàƒ⣵figkeit G […]
I’ve had a number of requests to explain some statistical topics and tests of significance. I’d rather not get involved in an explanation of general statistical concepts, which are perfectly well covered in many other places. However, I am going to post some notes up on “spurious significance”, which, after all, was part of the […]
Carl Wunsch has an interesting new preprint entitled: Abrupt climate change. An alternate view at his website.
I’ve been knuckling down to finishing off an article on the multiproxy study, Jones et al [1998], used in all the spaghetti diagrams. This is not robust to the Polar Urals reconstruction and a discussion of the Polar Urals site has taken on a life of its own. Many of the topics are familiar from […]
I’ve just updated my HADCRU2 dataset and, for good measure, also the current edition of CRUTEM2. I’ve updated my scripts and, for those brave souls that want their very own copy of HADCRU2 or CRUTEM2 in R format, I’ve posted up scripts to make R tables organized like time series usually are, with each column […]
The reason for looking at the form of stochastic process that bests suits the gridcell (and hemispheric) temperatures is that the statistical behavior of a random walk (one type of stochastic process) is very different than independent draw from a normal process.
Here are plots of the autocorrelation functions and time series for the 17 gridcells with the highest AR1 coefficients in an ARMA (1,1) model. The locations and patterns are a little curious.
Here is a plot of ARMA (1,1) coefficients for the CRU data set plotted up against a world map. I ‘ve not seen anything like this plotted up before. I think that the patterns are really quite pretty.
I tested some cells which were outliers under the ARMA(1,1) model. Here’s the result of the first cell that I looked at: the top panel shows the ACF – which has an unusual structure to say the least. The temperature anomaly plot is shown in the second panel and is also unusual to say the […]
We’ll reach 500,000 hits tomorrow (Aug. 14, 2005) since start of this blog on February 8, 2005. Traffic in July was nearly 130,000 hits. There are obviously a lot more visitors than people who post comments. If you’re someone that does visit the site, but who doesn’t feel comfortable posting comments on technical topics, I’d […]
