noun
circumzenithal arc
A meteorological optical phenomenon: an upside-down rainbow-like arc high in the sky, centered on the zenith. Technical term used in weather and photography contexts.
環天頂アークは、太陽が低いときに見られる珍しい光学現象です。
The circumzenithal arc is a rare optical phenomenon visible when the sun is low.
Compound of 環 (ring), 天頂 (zenith), and アーク (arc), directly describing the ring-like arc centered on the zenith.