Sundog, upper tangent arc, Parry arc, supralateral arc, and circumzenith arc

leyenda si/no

Fecha: 30.8.2005 Instrumento: f = 20 mm
Lugar: Four Mile Creek, NY Observador: Till Credner

Fecha:	30.8.2005	Instrumento:	f = 20 mm
Lugar:	Four Mile Creek, NY	Observador:	Till Credner

Approaching remnants of hurricane Katrina brought these high cirrus clouds with interesting optical effects. Hexagonal ice crystals produce such kind of arcs in the atmosphere.

See also:
further images of Halos
M.G.J. Minnaert: "Light and Color in the Outdoors", Springer-Verlag
R. Greenler: "Rainbows, Halos, and Glories", Cambridge University Press
L. Cowley: "Atmospheric Optics" web site
Meteoros site on Halos