Guest Post by Willis Eschenbach
People sometimes ask why I don’t publish in the so-called scientific journals. Here’s a little story about that. Back in 2004, Michael Mann wrote a mathematically naive piece about how to smooth the ends of time series. It was called “On smoothing potentially non-stationary climate time series“, and it was published in Geophysical Research Letters in April of 2004. When I read it, I couldn’t believe how bad it was. Here is his figure illustrating the problem:
Figure 1a. [ORIGINAL CAPTION] Figure 1. Annual mean NH series. (blue) shown along with (a) 40 year smooths of series based on alternative boundary constraints (1) – (3). Associated MSE scores favor use of the ‘minimum roughness’ constraint.
Note the different colored lines showing different estimates of what the final averaged value will be, based on different methods of calculating the ends of the averages. The…
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