PCA [33,34] is a widely-used method to analyze spatiotemporal
variability of an environmental variable. The technique allows
reduction of initial dataset size to a few representative variables,
called principal components (PCs) and often referred to as modes of
variability, which are obtained as linear combinations of the initial
variables. These combinations are obtained such that the new
variables account for the maximum fraction of variance contained
in the original dataset. Coefficients of the linear transformation,
known as loading factors,