What is the phenomenon that the sky is red?

The red sky is a rosy cloud phenomenon.

It is a rainbow-like light phenomenon, which appears in the morning and evening. It is not as regular as a rainbow, but as casual as spilled paint. Like abstract painting, there is a vague beauty. Generally called "sunrise" in the morning, the cloud itself is dim and huge in shape, but the sky is elegant rose; The "sunset glow" in the evening, also called "flaming clouds", is bright red in color, changeable in shape and small in cloud body.

According to Rayleigh scattering theorem, the transmitted light is inversely proportional to the fourth power of the wavelength of light, that is, the longer the wavelength, the less easily it is absorbed, so the blue-purple light with shorter wavelength is absorbed, while the red light with longer wavelength is reflected more, so the sky is mostly red in the morning or at night.

Rosy clouds and weather:

In ancient times, there was a saying that "the morning glow does not go out, and the sunset glow travels thousands of miles", because the morning glow is mostly caused by cumulonimbus clouds, which are very easy to develop into cumulonimbus clouds; Sunset clouds are mostly caused by light cumulus clouds, which will not cause precipitation. Generally, it indicates that it will continue to be sunny in a certain range in the next few days, which is conducive to travel.

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