Composition: Careless, I am anxious, anxious, anxious! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

Under the anticyclone, the weather is clear, without wind and clouds. There is no heat dissipation on the ground at night, and the temperature drops rapidly. On the contrary, the upper air is warmer, the air is warmer and colder, the air flow on the ground is stable, and all the dust particles are also deposited on the ground, so they cannot spread upward. At sunrise, the ground temperature is the coldest and the fog and dust are the thickest, so the sun is covered with this layer of fog and dust, so we can't see the sun when the sun just touches the ground. We can't see the sun until the sun rises, the ground is heated, and the fog and dust at low altitude have dissipated, so the sun comes out later on a sunny day. On the contrary, before the arrival of disastrous weather such as cyclones, the wind is strong, and water vapor and dust will not gather at low altitude. We can see the sun just rising behind the horizon. Therefore, the early sunrise of the sun is not a harbinger of sunny days.

* The sun rises early and the weather is difficult to rely on; The sun sent the mountain to wash clothes. (Hunan)

The sun rises early and the weather is difficult to rely on. The explanation is the same as before. At sunset, if the west is clear and cloudless, it means there is no storm in the west, so the weather is good.

* Sunrise and sunset are carmine, either rain or wind. (Hubei)

* The moon brought fire, and no rain fell on me. (Hubei)

If there is no carmine in the sun, no rain is wind. (Suzhou, Jiangsu)

* The sunset is a little red, and I get up in the middle of the night to set up an awning. (Southern Jiangsu)

* Moonlight is carmine, either rain or wind. (Suzhou, Jiangsu)

* In the evening, there is flood, rainstorm or strong wind. (Yiwu, Zhejiang)

White light (moonlight is similar) passes through the triangular glass block and becomes seven colors of light: red, orange, yellow, green, cyan, blue and purple. Among the solar light waves, the red light wave is the longest, one meter1300,000, and the purple light wave is the shortest, one meter is 25.6 million. Light waves from the sun or the moon encounter particles with the same wavelength in the atmosphere, and white light is dispersed into different colors and radiated in different directions. This phenomenon is called light scattering. Red light wave is the longest and most difficult to scatter, and its path is almost straight; Purple light wave is the shortest, and its scattering ability is sixteen times greater than that of red light wave, so its path is scattered away from the original straight line direction.

If the sun is at the zenith, at this time, the distance of white sunlight passing through the air circle is extremely short, and the particles encountered are the least, so the short-wave light scattered halfway is the least. In other words, almost all the original components of sunlight can be sent to our eyes in the original proportion, so when we look at the sun, it is white. If you look at other parts of the sky, it will be blue. This is because what we see is not the original component of sunlight, but the purple light and blue light that are most easily scattered, while the red light with longer wavelength propagates in a straight line. Purple light is the weakest sensitive to eyes, and only cyan light can see it, so the sky appears cyan. When the sun is about to set, the sun is oblique, and the distance that sunlight travels in the atmosphere is too long, which is dozens of times longer than when it is at the zenith. Then, the sun will encounter dozens of times the particles on the way. Almost all the short-wave sunlight from this direction is scattered clean and spread in other directions; What remains is only the red light wave with the longest wavelength and the least scattering. So when the sun is near the horizon, it always looks red.

The almost normal red color of the sun changes with the physical characteristics of the air. Whenever the disturbance in the air becomes more intense, that is, before the weather changes, the more dust and water droplets are contained in the air, the more white light is scattered, and the purer the red light wave becomes, turning into blood red or carmine. If the sky is very clean, even in the horizon direction, short-wave light can be transmitted with red-wave light, then the sunlight will be white and red. Because the air is clean, the weather will not get worse. The west also has the same saying: "The eye of the red sun comes with the water." "If you see the red sun running fast. Rain will follow. "

* The sun is back and screaming (Sichuan, Yulin, Guangxi)

When the sun goes down, there are dark clouds at the zenith, but there is no storm in the west. At that time, the sunshine must be very strong. The strong sunlight shines from the western horizon to the dense clouds at the zenith and then reflects to the ground, which is the phenomenon of solar reflection. In this way, the necessary condition for solar reflection is that there is no storm in the west, which is also the guarantee that the weather will remain sunny tomorrow.

* Cyclobalanopsis White Gang, an old day laborer sunbathing in the Ming Dynasty, (Jiangyin, Jiangsu)

On a clear summer day, after the sun goes down, you can see a blue and white light in the sky, passing through the zenith from west to east. This is the saying of Cyclobalanopsis. I saw Cyclobalanopsis glauca today, and it will be fine tomorrow. Why?

The scattering effect of atmospheric particles on each component of sunlight is different. Sunlight is a complex of red, orange, yellow, green, cyan, blue and purple light waves. Among them, the red light wave is the longest, the most difficult to scatter and the straightest; Purple light wave is the shortest, the easiest to scatter and the easiest to bypass. When the sun goes down, there is only the last solar disc left, which is far above the horizon. From this last solar disk, some white light enters the cosmic vacuum, and a very small part enters our atmosphere. However, the long wave that constitutes white light can only go straight and will not bend to the ground again. Only the most easily scattered blue-purple light waves can reach our eyes, so we can only see a "Cyclobalanopsis". Purple is not strong enough for human eyes, and it is not easy to detect its existence. The part without Cyclobalanopsis is gray and is "white hillock". Because this phenomenon only exists when the atmosphere is very stable and clean, that is, when the sky is clear, I saw Cyclobalanopsis glauca today and the weather will be fine tomorrow.

* It rains in the morning and sunny at night. (Hubei)

* Don't go out at dawn, and go to Wan Li Road at dusk. ("Tian Xing" on summer)

* Don't wash clothes in the morning, it will be fine tomorrow night. (Xining, Qinghai)

* Get up early to burn the sunset and wait for the water to make tea; It burns at night. It's too hot. (Baoding, Hebei, Chongqing, Sichuan)

* If the fire reaches the sky, it will definitely not be sunny. (Zhengding, Hebei)

* Burn Yin qi in the morning and eyes at night. (Zhejiang Xiangshan, Qinghai Hualong)

* Hongyun was born, so I advise you not to travel far; When the red cloud withers, it is as clear as water. (Hebei)

Sunlight that doesn't shine at sunrise is red. When this red light shines on the cloud, it becomes a red cloud. This is Xia Hong. In the morning, the sun is in the east. If there is red light, it is mostly at the zenith or west. That is to say, there are low clouds at the zenith or west. The weather always changes from west to east, and this low cloud must be slowly approaching the local area, indicating that rainy days are coming; On the contrary, the sun is in the west at night, and if there is red light, it is mostly in the zenith and east. Then, this low cloud that turns into a glow will continue eastward and gradually move away from the local area. If it rains, it won't rain locally, so it's sunny.

There is no red at sunrise, no rain and no wind. (Zhejiang righteous bird)

When the sun comes out, you can't see the red light, and the weather will get worse. Even if it doesn't rain, there will be wind. There is no red light in the morning, which means that the sky is covered with thick clouds, so that the red light that easily penetrates the atmosphere cannot penetrate into people's eyes.

* red heat to the top, the rain is full of wells. (Weixian County, Hebei Province)

* Dark clouds cover the fire, and rain is coming. (Hebei)

It will rain if there is a red cloud at the zenith. This cloud must be a cumulonimbus cloud or nimbostratus. Because they all carry thick ice drops, it is easy to rain. Since it is at the zenith, of course, it rains locally.

* East rainbow sun, west rainbow rain; South Red and North Red sell children. (Zhejiang, Hebei, Kaifeng, Henan, Zhengding)

* East carrot, west red, south red flooded. (Linfen, Shanxi)

* The east rainbow roared and the west rainbow rained. (Jiangsu)

* Sunny in the east and rainy in the west. (Sichuan Tongliang)

* Raindrops are dripping in the early rainbow, and the face is basking in the late rainbow. (Hebei)

* Rainbow over the river, grass withered all night. (Guangdong)

* It rains at night at the rainbow, and the cowshed at the rainbow is rotten at night. (Guangdong)

* Rain falls on the rainbow, and the rainbow will split tiles at night. (Guangdong)

* There are rainbows and rains in the east; There is a rainbow in the west, and people wear hemp fiber. (Wuxi, Jiangsu, Yiwu, Zhejiang)

Rainbow is formed by sunlight shining on water droplets floating in the air. Because the speed of light in air is greater than that in water, light is refracted. The internal reflection of water droplets can be more than once or several times in succession. Because the different wavelengths of white light-red, orange, yellow, green, cyan, blue and purple-have different properties, after these refraction and reflection, white light is dispersed into different color waves and presents different colors, so people look like beautiful light rings on the ground. The rainbow appears in the opposite direction to the sun. The rainbow at sunset is the rainbow in the east, and the rainbow in the morning is the rainbow in the west. Seeing a rainbow in the east means that it is raining heavily in the east; If you see a rainbow in the west, it will rain heavily in the west. Because temperate weather changes always occur in the west and then spread to the east; Therefore, the rain that has turned into a rainbow no longer comes to the local area; Only the rain that turns into a rainbow is the precursor of local precipitation.

The size of the sky phenomenon is usually measured by angle. The semicircle from the east through the zenith to the west is 180 degrees. From the horizon to the zenith, it is 90 degrees. The viewing angle of the rainbow radius is about 42 degrees. Its center must be on the extension line between the sun and the human eye. Obviously, the angle of the sun above the horizon must be equal to the angle of the rainbow arc center below the horizon. Therefore, only when the sun is nearly flat can we see the semi-circular rainbow completely. The higher the sun, the lower the rainbow head. Because the viewing angle of the rainbow is 42 degrees, if the sun is above 42 degrees above the horizon, in ordinary environment, you can't see the rainbow. Around noon, I didn't see the rainbow because the sun was too high.

The so-called south rainbow and north rainbow can only be seen at noon. Near the equator, between the Tropic of Cancer (23.5 north latitude-23.5 south latitude), the sun is at the zenith almost all year round, so there is no possibility of south rainbow and north rainbow. But when the latitude is above 40, in winter, when the sun is at its lowest point in the south, it is easy to see the North Rainbow. Because at 40 degrees north latitude, the sun from the winter solstice is only 26.5 degrees from the horizon, which is lower than 42 degrees, so if there is a shower in the north, you can see the rainbow head on the horizon. As usual, winter should be dry and rainy (as far as China is concerned). If there is a rainbow in the north, obviously it can rain heavily at this time, and this winter must be hot and humid. Such abnormal weather is bad for human life and crops, so it is an ominous sign. In our country, the sun will never reach the north of zenith except in the south of Xiamen, so there will never be a south rainbow.

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