Sentences with phrase «autocorrelation coefficients»

The very inconsistency of the series within proxy networks such as Mann et al 2008 argues forcefully against the interpretation of high empirical autocorrelation coefficients as being imported from a climate «signal», as opposed to being an inherent feature of the proxies themselves.

The benchmarking of RE statistics was an issue that was put into play in McIntyre and McKitrick 2005a, where we observed that you could get high RE statistics from pseudoproxies with autocorrelation coefficients mimicking the autocorrelation coefficients of actual proxies, rather than the very low - order AR1 coefficients assumed (without proof) by climate scientists.

Ammann and Wahl (2007) has argued that using autocorrelation coefficients estimated from actual proxies results in

The more meaningful statistical question, however is this one: Given the «null hypothesis» of red noise with the same statistical attributes (i.e., variance and lag - one autocorrelation coefficients) as the actual North American ITRDB series, and applying the MBH98 (non-centered) PCA convention, how likely is one to produce the «Hockey Stick» pattern from chance alone.

The autocorrelation of the «blade» segment of «hockey - stick» shaped proxies is significantly higher than the rest of the series, this biases their estimates of autocorrelation parameters because their model assumes a stationary autocorrelation structure, making their simulated series unrepresentative of most of the length of hockey - stick series, as can be seen in this graph of lag - 1 autocorrelation coefficients.

later, «For ODP 1218 the estimated autocorrelation coefficient is ϕ = 0.87 and the variance of the ∈ disturbances is 0.41 at a time step of 4.3 kyr.»

The noise model involves two complementary approaches: dynamic noise after orbital tuning (DYNOT) and lag - 1 autocorrelation coefficient (ρ1).

Not exact matches

We found no evidence of population structure and little evidence of spatial autocorrelation of parasite genotypes (correlation coefficients < 0.03 among parasite pairs in distance classes of 1 km, 2 km and 5 km; p value < 0.01).

(Note that empirical AR1 coefficients place less structure on the autocorrelation than the hosking.sim simulations used with the NOAMER tree ring network in our 2005 simulations and simplify this aspect of this analysis.)