Why does the sky look high in autumn?

Autumn is often accompanied by light clouds, high skies and suitable temperatures in the morning and evening, so people often use the term "autumn is high and cool". So, how did such weather come about?

In autumn, in the Northern Hemisphere, the sun gradually changes from direct to oblique rays around the summer solstice, with shorter daytime hours and longer nights. During the day, the ground absorbs less heat from the sun's rays than in the summer, and less moisture evaporates from the ground into the air.

In addition, with the gradual withdrawal of warm and humid air and the slow entry of cold air, and gradually occupy most of the provinces and regions of our country, the temperature begins to decrease, which will also reduce the evaporation of water vapor on the ground, therefore, there are fewer clouds in the sky, even if there are clouds, it is a light layer, and the visibility is very good. As a result, the sky is clear during the day and the sky is full of stars at night, making people feel that the autumn sky is particularly high.

Since the sky is clear during the day and the sky is not covered by clouds at night, the heat on the ground can be freely dissipated. The heat absorbed by the sun during the day is not enough to make up for the heat dispersed at night, so the temperature of the ground gradually decreases, but not much, so it is cold at first. At this time, people sweat less, and even if they sweat a little, the dry and cool air will make the sweat on people's bodies evaporate quickly, giving people a cool and comfortable feeling.

Because it's already high.

The autumn sky is grayish-white, because when it comes to the season of falling leaves, the autumn sky always looks desolate.

Autumn Sky Autumn is a season of high wind, a season of harvest, the fragrance of osmanthus, and of course, a season of beauty. Autumn skies are the most beautiful. In the morning, the sky is quiet, the color is as blue as the sea, as blue as a wash, the sun "gets up", rises from the east, the sun is not too fierce, shining on people, making people feel very warm.

At noon, the sun is extremely violent, like an angry uncle, shining on people is particularly hot, but there are still a few small birds flying freely in the air, from time to time making a "chirp, chirp" sound, as if to say: "It's hot, it's hot, it's hot!" "One afternoon, the sunlight diminished a lot, and without much sunlight, one could faintly see the clouds in the sky, some of them like rabbits feeding, some like leopards running, and some like a great dragon soaring.

Although the sun's rays are shining on the eyes, I can't see clearly, but I can see that Huaidongyuan is already very satisfied!

In the evening, the sun was not as bright as at noon, the blue sky turned pale red as if drunk, the sun gradually took off its orange coat and replaced it with red, and everything around it was so red, it slowly returned to the bosom of the western mountain, the light was faint, like a match about to be extinguished. It set, leaving behind a red glow, as if a fairy's garment had fallen from the sky to the mortal world, and the surroundings were very quiet. People are bathed in the glow, it is so pleasant!

The autumn sky is very blue, very blue. It's so blue and charming, it's so blue that it's trembling. The autumn sky is an ethereal sapphire crystal.

There is no embellishment of floating clouds, and there is only the landscape when the geese fly south. Looking up, the whole body was in a leisurely "big" shape, and it seemed that at that moment, the mind was suddenly much broader. At this moment, we were surprised to find that the sky seemed to become unreachable, is this a reminder not to dream unrealistically?

Reasons why the sky becomes more inverted and blue in autumn:

1. The position of the sun in the sky becomes lower, and as the days gradually become shorter, the sun's trajectory in the sky gradually sinks to the horizon, increasing the amount of blue light scattered and visible to the naked eye on the surface, so the sky becomes bluer.

2. The lower the humidity, the less clouds and fog, in autumn, not only the temperature is reduced, but the humidity is also reduced, due to the reduction of water vapor in the air, the clouds are not easy to form, so the sky appears in the eyeballs, appearing bluer.

3. The warm color of the leaves in autumn and the blue of the sky are complementary colors, because the blue and orange are in opposite positions on the color wheel, so in autumn, under the background of gold, orange and red leaves, the already blue sky becomes bluer. Tong liter.

Leaves aren't the only thing that changes color in the fall. Have you ever looked up at the sky on a crisp autumn day and noticed that its colors are so vivid and clear? It's not what you might think, the autumn skies are indeed bluer than ever, and there's a scientific basis for that.

To understand why the colors of the sky are more vivid in autumn, you first need to understand why the sky is blue.

Why is the sky blue? This is a classic question that many curious children will ask. This question is not like any of the other profound mysteries of the universe, and we have the answer to this question thanks to John William Stratt.

The 19th-century physicist was awarded the Nobel Prize in 1904 for his discovery of argon. However, what really made Stratt famous in history was his discovery of Rayleigh's scattering law. Because he inherited the title, he was called Lord Rayleigh the Third, and this law was named after him.

The law of Rayleigh scattering explains how light takes on different colors when scattered by atmospheric molecules.

Let's review the basic principle that the sky appears blue: sunlight is made up of many colors, and different colors of light have different wavelengths. For example, red light has the longest wavelength, while at the other end of the spectrum, violet and blue light have the shortest wavelength.

The sun's rays pass through the Earth's atmosphere and encounter a thick layer of atmospheric molecules and dust particles. These particles are similar in size to shorter wavelengths of light, so they are more likely to scatter blue and violet light。Finally, we have the blue sky that we see.

But notice that although we see a blue sky, it is actually purple. The reason why we see blue instead of purple is determined by the physiology of the eyeball, which is more sensitive to blue.

Now that we understand why the sky is blue, let's go back to the original question: Why does the sky get bluer in late autumn? There are several reasons for this.

The position of the sun in the sky becomes lower

This is as Wildcard Weather says: "The sun's rays are no longer above our heads, but at an angle to the sky." Rayleigh scattering scatters more blue light to the naked eye, while indirect light reduces the degree to which the naked eye receives red and green light. ”

The lower the humidity, the fewer clouds there are

The scorching summer continues to set new highs, and the cool autumn finally brings a hint of coolness. Moreover, not only the temperature has decreased, but so has the humidity. As water vapour decreases in the air, clouds are less likely to form and fog is no longer shrouded in the city centre.

And so there was a clear sky above us.

The warm colors of the autumn leaves complement the blue of the sky

If you've ever made color rings in art class, you'll know that blue and orange are complementary colors. Because they are "opposites" on the color wheel, the clear beauty of the already blue sky is accentuated in autumn against the backdrop of gold, orange and red leaves.

Tadpole staves compiled from mnn, translated by Yigrainchen, ** with permission.

In autumn, not only the leaves change color. Have you ever looked up at the sky on an autumn day and noticed that its colors are so vivid and vibrant? It's not your imagination.

The autumn sky is indeed bluer than before. All of this has a scientific basis. To understand why the sky is more colorful in autumn, first, you need to understand why the sky is blue.

The sun's rays are no longer above our heads, but at an angle to the sky. Rayleigh scattering scatters more blue light onto the naked eye, while indirect light reduces the reception of red light by the naked eye. And the degree of the green light.

Summers are hot and the temperature is constantly rising, and autumns are cool, and finally bring coolness. Moreover, not only the temperature has decreased, but so has the humidity. As the amount of water vapor in the air decreases, clouds are less likely to form and fog no longer covers the city center.

Then, above us was a clear sky. If you did a color wheel in art class, you'll know that blue and orange are complementary colors. Because they are in a "relative" position on the color wheel, in autumn, under the golden, orange and red leaves, the blue sky is already clear and the clear beauty is more prominent.

There is more than one color in the autumn sky, when the sun first rises, the sky is red, then the sky turns white, during class, the sky is blue, and in autumn, the sky is colorful.

The autumn sky is blue. The geese flew south in a neat line, and the voice of the geese was chirping, as if to say, "Dear friends, I will definitely come back!" "The fields are yellow in autumn. When the rice is ripe, when the millet is ripe, the wheat is ripe.

The autumn sky is beautiful. In autumn, the autumn is high and cool, in the blue sky, there are a few white clouds as white as snow, strange shapes, the long white clouds, like a beautiful scarf. The sky added a sight.