Multipolar wind distributions

The poles featuring in this paper stem directly from Maxwell’s classical harmonic polynomials. Here, we employ them in a systematic approach to the representation of wind probability distributions in the plane. Symmetry suggests the number of poles (and the degree of the polynomial) strictly necessary in a specific situation. In this model, multipolar tensors of different ranks (corresponding to homogeneous polynomials of different degrees) embody different components of wind climate. When applied to the data of a wind farm in Sicily (Italy), this strategy proves that an octupolar distribution (with 3 poles) is the best fit. A quadrupolar distribution (with 2 poles) is found to be equivalent to a distribution that is elsewhere called offset elliptical normal.