Why do rainbows appear on sunny days?

20 10 On September 23rd, a sunny day, a rainbow appeared in the sky of Zhengzhou, Henan Province. Meteorologists say that this is a normal phenomenon of sunlight refraction, and many people call it "the smiling face of the sky". In everyone's impression, there must be a rainbow after the storm. Where is the rainbow on such a sunny day?

The director of Zhengzhou Meteorological Observatory said that this kind of landscape appeared because the water particles in the sky reached a certain density, and the sunlight reflected and refracted to produce seven colors, which are common rainbows.

Meteorologists say that in spring and autumn, the temperature difference between high and low air is large, and water vapor will freeze at high altitude, making the air density at high altitude higher than that at low altitude, forming an "inverted prism".

When the sky is clear and there are few clouds, when the sun shines on this thin layer of curved small ice crystals at a certain angle, it will form refraction and there will be an upside-down rainbow spectacle. This rainbow has nothing to do with rain and foggy weather.