The rainbow after the rain is very beautiful. What conditions are needed to form this phenomenon?

We all know that clouds are usually white. This is due to the color of water vapor clouds that shine across the sky. Like the white gas we see from a boiling kettle. They are all white. Tiny water vapor droplets instantly condense and turn white when exposed to light, so the clouds we see in the sky are all white. But if it is a particularly thick cumulonimbus cloud, the sun below it will not shine, and it will look black, so we often say it is a black cloud.

But clouds also come in various colors. Some friends may not know why the clouds still show bright colors. In fact, they are formed by sunlight diffracted by small water droplets and small ice crystals in clouds. It is a typical "Japan-China" phenomenon.

Have you ever seen colorful clouds? It forms easily in such weather conditions, and its appearance says nothing.

We all know that prisms can emit light. When a beam of sunlight hits a prism at the right angle, the color of the sunlight will break down into seven colors: red, orange, yellow, green, blue and violet. This is because light is refracted by the prism and exhibits different visibility. Spectral bands.

When colorful auspicious clouds appear in the sky, these small water droplets and ice crystals form water vapor in the clouds. Like prisms, the reflected sunlight is diffracted and broken into colors.

Although colorful auspicious clouds are rare, the frequency of occurrence is not particularly low, and may be slightly lower than the probability of a rainbow. The weather conditions that form colorful auspicious clouds are mainly as follows:

Sufficient sunshine during the day and better lighting conditions;

There are thin clouds in the sky, such as altocumulus, cirrocumulus, lenticular clouds, etc. . These talents are relatively thin and have uniform small droplets of water or small ice crystals, like pearlite clouds, which create very bright light.

At right angles to the sun. Unlike rainbows, which appear on the side facing away from the sun, colorful clouds usually appear on the side of the sun.

Although colorful clouds are rare, they are easy to form under the above three weather conditions, but the time after they appear is usually very short, only about 1 to 5 minutes, and they are not easy to see.

People have many opinions about the appearance of colorful clouds. Some people think that they represent good luck, so they call them "colorful clouds", but others say that the appearance of colorful clouds means the arrival of a storm. From the perspective of weather phenomena, colorful clouds appear. There are more cases of rainfall behind the clouds, but there is no necessary connection between the two.