Article

Approximating Dendrochronology Smoothing Splines Using Conventional Techniques

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Abstract

Dendrochronologists study tree rings to reconstruct past climatic conditions. To do so, non-climatic influences must be separated from climatic trends by fitting smoothing splines–flexible, which are weighted, piece-wise polynomials used in many fields. In dendrochronology, the standard approach is to use a method developed by Cook and Peters to select the smoothing parameter of the spline (1981). The Cook and Peters method is unique to dendrochronology; other, more conventional smoothing parameter selection methods are not used in dendrochronology. Connecting the Cook and Peters method with a traditional approach would provide more insight into the Cook and Peters method and allow access to the robust set of techniques available with conventional splines. Our research finds a direct equivalence between traditional splines and the Cook and Peters method by setting the degrees of freedom for the spline, which can produce approximately equal splines to the Cook and Peters method.

Keywords: cubic smoothing spline, tree-ring processing, parameter selection

How to Cite:

Riendeau, E., Nolan, E. & Bussberg, N., (2025) “Approximating Dendrochronology Smoothing Splines Using Conventional Techniques”, North Carolina Journal of Mathematics and Statistics 11(1). doi: https://doi.org//ncjms.1581