Parhelia Sentence Examples
Less brilliant are the parhelia of the outer halo.
The parhelia are most brilliant when the sun is near the horizon.
The parhelia (p) were explained by Mariotte as due to refraction through a pair of alternate faces of a vertical prism.
As the sun rises, the rays enter the prisms more and more obliquely, and the angle of minimum deviation increases; but since the emergent ray makes the same angle with the refracting edge as the incident ray, it follows that the parhelia will remain on the parhelic circle, while receding from the inner halo.
The axes will take up any position, and consequently give rise to a continuous series of parhelia which touch externally the inner halo, both above and below, and under certain conditions (such as the requisite altitude of the sun) form two closed elliptical curves; generally, however, only the upper and lower portions are seen.Advertisement