Supplementary Material (Version 3) to "Advances in unsupervised parameterization of the seasonal-diurnal surface wind vector" (https://doi.org/10.3390/meteorology4030021)

Supplementary Material (Version 3) to the paper "Advances in unsupervised parameterization of the seasonal-diurnal surface wind vector" published in MDPI Meteorology. including summaries of results for the locations of the study and R scripts to reproduce the analyses and results and apply the to other locations.

ABSTRACT
The Offset Elliptical Normal (OEN) mixture model represents the seasonal–diurnal surface wind vector for wind engineering design applications. This study upgrades the parameterization of OEN by accounting for changes in format of the global database of surface observations, improving performance by eliminating manual supervision and extending the scope of the model to include skewness. The previous coordinate trans-formation of binned speed and direction, used to evaluate the joint probability distributions of the wind vector, is replaced by direct kernel density estimation. The slow process of sequentially adding additional components is replaced by initializing all components together using fuzzy clustering. The supervised process of sequencing each mixture component through time is replaced by a fully automated unsupervised process using pattern matching. Previously reported departures from normal in the tails of the fuzzy-demodulated OEN orthogonal vectors are investigated by directly fitting the bivariate skew generalized t distribution, showing that the small observed skew is likely real but that the observed kurtosis is an artefact of the demodulation process, leading to a new Offset Skew Normal mixture model. The supplied open-source R scripts fully automate parametrization for locations in the NCEI Integrated Surface Hourly global database of wind observations.

Version3 updates the R scripts with improvements and minor bug fixes, particularly to the way observed calms are handled. It corrects a serious bug in Version 2 of the autothread() function. See the Read.Me.pdf file for further details.