What is the phenomenon of the sun playing an umbrella?

"Sun umbrella" is a kind of thermal halo phenomenon, which is called solar halo in written language.

Such a sky phenomenon at noon often indicates that the weather will change. There are apertures around the sun or moon, which are colorful. People call it "wind circle" and meteorology calls it halo. The aperture around the sun is called solar halo, which is formed by the refraction or reflection of ice crystals when sunlight passes through clouds.

Such a sky phenomenon at noon often indicates that the weather will change. Ice crystals around the sun and in the same circle with the sun can refract the light of the same color into people's eyes, forming a halo of internal infrared violet. When a cirrostratus composed of ice crystals appears in the sky, one or more colored halo rings with internal infrared violet centered on the sun often appear around the sun, and sometimes there are many colored or white spots and arcs. These halo rings, light spots and arcs are collectively called ice halo.