An optical model of the parhelic circle is computed which includes the Stokes parameters of polarization. The model is based on one of two closely related mechanisms in crystals which are known to exist in cirrus clouds. An analysis of the circumstances of occurrence shows that one mechanism—external reflection from the side faces of ice crystal plates with c axes vertical—probably generates most parhelic circles.
© 1979 Optical Society of America
David K. Lynch, "Polarization models of halo phenomena. I. The parhelic circle," J. Opt. Soc. Am. 69, 1100-1103 (1979)