parhelic circle vs solar halo

parhelic circle and solar halo both are nouns.

Word	Noun	Adjective	Verb	Adverb
parhelic circle	Yes	No	No	No
solar halo	Yes	No	No	No

As nouns, parhelic circle and solar halo are synonyms defined as:

parhelic circle and solar halo: a luminous halo parallel to the horizon at the altitude of the sun; caused by ice crystals in the atmosphere

Other synonyms of parhelic circle include parhelic ring.

parhelic circle (noun)	solar halo (noun)
a luminous halo parallel to the horizon at the altitude of the sun; caused by ice crystals in the atmosphere	a luminous halo parallel to the horizon at the altitude of the sun; caused by ice crystals in the atmosphere