Definition

1. Noun:
   • A luminous halo parallel to the horizon at the altitude of the sun; caused by ice crystals in the atmosphere: A parhelic ring is a specific type of atmospheric optical phenomenon. It appears as a bright, white circle of light running horizontally through the sun, parallel to the horizon. It is distinct from the more common 22° halo and is created by the reflection and refraction of sunlight by plate-shaped ice crystals suspended in the atmosphere.

Usage

• The term is used in the context of meteorology, atmospheric physics, and sky observation to describe a specific and relatively rare halo phenomenon.
• It is a technical, scientific term.

Examples

• Noun:
  • We were fortunate to observe a complete parhelic ring during the cold winter morning.
  • The parhelic ring, along with sundogs, created a spectacular display in the sky.
  • Photographers often seek conditions that produce atmospheric phenomena like the parhelic ring.

Advanced Usage

• "To observe a parhelic ring": To see and identify this specific halo phenomenon.
  • Only under very specific atmospheric conditions can one observe a parhelic ring.
• The parhelic ring is often discussed in relation to other halos, such as the 22° halo, circumzenithal arc, and sundogs (parhelia), which may appear along its path.

Variants and Related Words

• Parhelic circle: An alternative name for the parhelic ring.
• Parhelion (plural: parhelia): Also known as a "sundog," a bright spot that often appears on the parhelic ring to the left and/or right of the sun.
• Halo: The general term for a ring of light around the sun or moon, caused by ice crystals.
• Atmospheric optics: The scientific field that studies phenomena like the parhelic ring.

Synonyms

• Parhelic circle: The direct synonym.
• White horizontal halo: A descriptive synonym.

Related Phrases / Compound Terms

• Ice crystal halo: A general term for halos formed by ice crystals, which includes the parhelic ring.
• Atmospheric halo display: A event featuring multiple halo phenomena, which may include a parhelic ring.

Notes

• The parhelic ring is a complete or partial circle, unlike sundogs which are distinct bright spots. Sundogs are frequently located on the parhelic ring.
• This phenomenon is a sign of the presence of cirrus or cirrostratus clouds high in the troposphere, which contain the necessary plate-shaped ice crystals.

Noun

1. a luminous halo parallel to the horizon at the altitude of the sun; caused by ice crystals in the atmosphere