The 46° halo is similar to, but much larger and fainter than, the more common 22° halo. The 46° halo forms when sunlight enters randomly oriented hexagonalice crystals through a prism face and exits through a hexagonal base.[2] The 90° inclination between the two faces of the crystals causes the colours of the 46° halo to be more widely dispersed than those of the 22° halo. In addition, as many rays are deflected at larger angles than the angle of minimum deviation, the outer edge of the halo is more diffuse.[3]
To tell the difference between a 46° halo and the infralateral or supralateral arcs, one should carefully observe sun elevation and the fluctuating shapes and orientations of the arcs. The supralateral arc always touches the circumzenithal arc, while the 46° halo only achieves this when the sun is located 15–27° over the horizon, leaving a gap between the two at other elevations. In contrast, supralateral arcs cannot form when the Sun is over 32°, so a halo in the region of 46° is always a 46° halo at higher elevations. If the Sun is near the zenith, however, circumhorizontal or infralateral arcs are located 46° under the Sun and can be confused with the 46° halo. [4][5]
References
^The 46° halo was first explained as being caused by refractions through ice crystals in 1679 by the French physicist Edmé Mariotte (1620–1684). See: Mariotte, Quatrieme Essay. De la Nature des Couleur (Paris, France: Estienne Michallet, 1681). Sun dogs as well as the 22° and 46° halos are explained in terms of refractions from ice crystals on pages 466–524.
^"46°-halo". Arbeitskreis Meteore e.V. from the original on 31 March 2007. Retrieved 2007-04-16.
^Les Cowley (?). "46° Halo Formation". Atmospheric Optics. Retrieved 2007-04-16. (including an illustration and an animation)
^Les Cowley (?). "Is it a 46° halo or a supra/infralateral arc?". Atmospheric Optics. Retrieved 2007-04-16.
Atmospheric Optics - 46° Radius Halo - including a HaloSim computer simulation and an Antarctica fish eye photo.
March 06, 2023
halo, rare, atmospheric, optical, phenomenon, that, consists, halo, with, apparent, radius, approximately, around, solar, elevations, often, confused, with, less, rare, more, colourful, supralateral, infralateral, arcs, which, cross, parhelic, circle, about, l. A 46 halo is a rare atmospheric optical phenomenon that consists of a halo with an apparent radius of approximately 46 around the Sun At solar elevations of 15 27 46 halos are often confused with the less rare and more colourful supralateral and infralateral arcs which cross the parhelic circle at about 46 to the left and right of the sun 1 Sun dogs with a larger and fainter 46 halo and a 22 halo with an upper tangent arc The 46 halo is similar to but much larger and fainter than the more common 22 halo The 46 halo forms when sunlight enters randomly oriented hexagonal ice crystals through a prism face and exits through a hexagonal base 2 The 90 inclination between the two faces of the crystals causes the colours of the 46 halo to be more widely dispersed than those of the 22 halo In addition as many rays are deflected at larger angles than the angle of minimum deviation the outer edge of the halo is more diffuse 3 To tell the difference between a 46 halo and the infralateral or supralateral arcs one should carefully observe sun elevation and the fluctuating shapes and orientations of the arcs The supralateral arc always touches the circumzenithal arc while the 46 halo only achieves this when the sun is located 15 27 over the horizon leaving a gap between the two at other elevations In contrast supralateral arcs cannot form when the Sun is over 32 so a halo in the region of 46 is always a 46 halo at higher elevations If the Sun is near the zenith however circumhorizontal or infralateral arcs are located 46 under the Sun and can be confused with the 46 halo 4 5 References Edit The 46 halo was first explained as being caused by refractions through ice crystals in 1679 by the French physicist Edme Mariotte 1620 1684 See Mariotte Quatrieme Essay De la Nature des Couleur Paris France Estienne Michallet 1681 Sun dogs as well as the 22 and 46 halos are explained in terms of refractions from ice crystals on pages 466 524 46 halo Arbeitskreis Meteore e V Archived from the original on 31 March 2007 Retrieved 2007 04 16 Les Cowley 46 Halo Formation Atmospheric Optics Retrieved 2007 04 16 including an illustration and an animation Les Cowley Is it a 46 halo or a supra infralateral arc Atmospheric Optics Retrieved 2007 04 16 Supralateral arc Arbeitskreis Meteore e V Retrieved 2007 04 16 External links EditAtmospheric Optics 46 Radius Halo including a HaloSim computer simulation and an Antarctica fish eye photo Retrieved from https en wikipedia org w index php title 46 halo amp oldid 1078448188, wikipedia, wiki, book, books, library,
