In winter, why is the sky red at night?

Sunset. The same reason as the blue sky during the day is that it is a phenomenon of light refraction because the angle of incidence is different during the day and evening. So you see light with a longer wavelength.

There are two reasons for this: on the one hand, because of the city's light pollution. The landlord looks at the sky in the city at any night, the sky is guaranteed to be not black, but red, if the landlord goes to the suburbs, it is guaranteed to see at leastDark blueof the sky.

If the landlord could go to the mountains, the sky would be dark. This proves that the color of the urban sky is due to light pollution. On the other hand, the atmosphere pairsSunlightThere are weakening effects, one of which is scattering.

How did the red sky come about? "After the rain, the clouds are thicker, and when the sun goes down, the sun's rays pass through the clouds and scatter them, which gives rise to this (red) look. The staff explained.

In layman's terms, when the sun goes down, the angle at which the light shines is oblique.

As a result, the distance the light passes through the clouds becomes longer. Because of the convective cloud disk after the rain.

The water vapor absorbs the light in other wavelengths, leaving behind a longer wavelength of red light, so we can see the red sky. As for why the riverside friends didn't see it, the staff also said, "Thundershowers from afternoon to evening."

Mainly in the north of the city, there is no rain on the riverside, and the rain will change the humidity near the ground. ”

So different places have different colors of sky. Isn't it after the wind and rain that you can see the rainbow? Experiencing the baptism of heavy rain is worthy of meeting the red sky. I also wish you all the privilege of seeing this beautiful sky.

1. Because of the scattering of light, the light with a relatively long wavelength in the sunlight encounters the dust in the air and is blocked for scattering, so the sky at night will be red Generally called fire clouds.

2. It is related to the distance of the sun, the sun in the evening is far away from the sky, the wavelength of red light is more than the wavelength of light in other bands, and the penetration is also strong, at a long distance, most of the red light can shine on the clouds above, and other lights cannot, so the sky in the evening is red.

3. This is related to the water vapor in the sky, in the spectrum, the refractive index of red in the water is larger than that of other colors of light, so when other lights are invisible, red light can still be seen.

4. It is the street lamp that the clouds in the sky reflect the ground, because most of the street lamps are warm colors, and the red light is the lowest frequency in the visible light, and the penetration is quietly poor, and it is reflected by the clouds.

5. To sum up, this is the reason why the sky turns red at night.