Please tell me the difference between "halo" and "hua".

Let me answer you!

Just a few simple points, I hope it will be helpful to you!

1. Halo and Hua appear at different times when the weather changes from sunny to cloudy and rainy. It can also be said that clouds appear at different heights. Contemporary meteorological scientific practice shows that when the weather changes from sunny to rainy, people first see cirrostratus clouds, and then medium-low clouds that produce rainfall appear in the sky. When cirrostratus clouds appear, it depends on whether the subsequent medium and low clouds develop. If they develop, the result will be rainfall. That is, cirrostratus clouds usually appear at the front of cyclones. Hundreds of kilometers behind the front is the cloud and rain area caused by the front. As the surface front moves closer, the accompanying weather will be lower and lower clouds, gradually increasing winds, and precipitation. Therefore, the appearance of the sun and moon halo means that stormy weather is coming, such as "the sun halo rains at midnight, the moon halo winds at noon", "the moonlight is flailed, and heavy rain falls", and "the moon is hairy, and heavy rain rushes the trench". explain. Of course, this does not mean that the appearance of a solar halo must be a sign of rain, and the occurrence of a lunar halo must be windy. It also depends on other weather conditions. If only the edge of the cyclone passes here, there may not necessarily be rain, but the clouds will thicken, the wind will increase, and the wind direction will change. Cirrostratus clouds also exist on the outer edges of tropical cyclones, which can also form haloes. Therefore, during typhoon season, when you see cirrus clouds and halos in the sky at low latitudes, it may be a sign of an approaching typhoon.

2. Most of the cirrus clouds are ice crystals. Ice crystals are mainly hexagonal columnar and hexagonal flakes. On one side of the hexagon, each internal angle is 120°, which is the angle between two adjacent sides. The angle between two alternate sides is 60°. The angle between the hexagonal face and the side The included angle is 90°. Halos are formed when light from the sun and moon is refracted or reflected by ice crystals in the cloud before reaching the human eye. The refraction of light when passing through ice crystals is the same as the refraction of light when passing through a prism. And does light refract (reflect) twice when it passes through a prism? Just like the difference between neon and rainbow. Since the sunlight is reflected twice after passing through the water droplets, the light energy loss is much greater than the light energy reflected once, so the brightness of the "neon" is much darker than the brightness of the "rainbow", so it is also called a secondary rainbow, and the secondary rainbow It is located above the main rainbow, and below the secondary rainbow is the main rainbow. The color distribution of the main rainbow is outer red and inner purple, and the color distribution of the secondary rainbow is outer purple and inner red.

3. Do you know that Waldo is produced in photic stratocumulus clouds and photic altocumulus clouds, and their heights are mostly 2 500 to 5 000 meters. If such clouds thicken systematically, precipitation often forms. There is a proverb that "big flowers are sunny, small flowers are raining". Hua is generated due to the diffraction of sunlight or moonlight on small cloud droplets (ice crystals or small raindrops) in the clouds. Therefore, the smaller the diameter of the cloud droplets, the larger the halo. The size of the flower varies. It shows that when the apparent radius of the bloom changes from small to large, the water droplets in the cloud are dispersed and reduced, which indicates sunny weather; when the apparent radius of the bloom changes from large to small, the water droplets in the cloud increase and become larger, indicating cloudy and rainy weather. The more uniform the size of the cloud droplets, the more vivid the colors of the halo. Therefore, as long as the opening angle of the colorful ring is measured, the average size of the cloud droplets can be roughly estimated.