The subparhelic circle is a rare

halo Halo, halos or haloes usually refer to: * Halo (optical phenomenon) * Halo (religious iconography), a ring of light around the image of a head HALO, halo, halos or haloes may also refer to: Arts and entertainment Video games * Halo (franchise), ...

, an

optical phenomenon Optical phenomena are any observable events that result from the interaction of light and matter. All optical phenomena coincide with quantum phenomena. Common optical phenomena are often due to the interaction of light from the sun or moon wit ...

, located below the

horizon The horizon is the apparent line that separates the surface of a celestial body from its sky when viewed from the perspective of an observer on or near the surface of the relevant body. This line divides all viewing directions based on whether ...

. It passes through both the

subsun A subsun (also spelled sub-sun) is an optical phenomenon that appears as a glowing spot visible within clouds or mist when observed from above. The subsun appears directly below the actual Sun, and is caused by sunlight reflecting off of numer ...

(below the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared rad ...

) and the

antisolar point The antisolar point is the abstract point on the celestial sphere directly opposite the Sun from an observer's perspective. This means that the antisolar point lies above the horizon when the Sun is below it, and vice versa. On a sunny day ...

(opposite to the Sun). The subparhelic circle is the subhorizon counterpart to the

parhelic circle A parhelic circle is a type of halo, an optical phenomenon appearing as a horizontal white line on the same altitude as the sun, or occasionally the Moon. If complete, it stretches all around the sky, but more commonly it only appears in sections. ...

, located above the horizon. Located on the subparhelic circle are several relatively rare optical phenomena: the

, the subparhelia, the 120° subparhelia, Liljequist subparhelia, the

diffuse arc Diffusion is the net movement of anything (for example, atoms, ions, molecules, energy) generally from a region of higher concentration to a region of lower concentration. Diffusion is driven by a gradient in Gibbs free energy or chemical p ...

s, and the

Parry antisolar arc PARRY was an early example of a chatbot, implemented in 1972 by psychiatrist Kenneth Colby. History PARRY was written in 1972 by psychiatrist Kenneth Colby, then at Stanford University. While ELIZA was a tongue-in-cheek simulation of a Rog ...

s. (including a computer simulation) (including a photo and a computer simulation) On the accompanying photo centred at the antisolar point, the subparhelic circle appears as a gently curved horizontal line intercepted by anthelic arcs.

References

External links

Another photo from a plane

{{climate-stub Atmospheric optical phenomena fr:Cercle parhélique#Cercle subparhélique

See also

References

External links