Why are the skies higher in autumn and winter than in summer?

The Earth rotates from west to east while revolving around the Sun. The combination of the Earth's rotation and its orbital motion gives it the day-night alternation and the seasons on Earth (the speed of the Earth's rotation and revolution is uneven). At the same time, due to the gravitational influence of the sun, the moon, and nearby planets, as well as the earth's atmosphere, oceans, and internal materials, the direction of the earth's axis of rotation in space and the earth's body changes.

The inertial centrifugal force generated by the rotation of the earth causes the spherical earth to gradually expand from the poles to the equator, becoming the current spheroid with slightly flattened poles and slightly bulging equators, and the polar radius is about 21 kilometers shorter than the equatorial radius.

Because the clouds are lower in summer than in autumn and winter, it gives the illusion that the sky is getting lower.

Spring, summer, autumn and winter are empty, the sky is windy and cloudy in spring, the sky is bluer in summer because ultraviolet rays are stronger in summer, there are many gorgeous dark clouds in autumn sky, and there is basically no color in the sky in winter and no clouds can be seen. Mainly because the winter is too cold and the light is not strong enough to see the blue sky.

Spring, summer, autumn and winter empty

The sky in spring is cloudy and windy, so spring is also a season for kite flying, and there will be a lot of colorful kites taking off from the ground before spring, and the spring light is not strong, so the color of the sky is relatively light.

The summer sky is the most colorful, because there is a lot of rain in the summer, so you can see very beautiful lightning, and in the summer there is a lot of light, and the light spreads blue through the clouds, so the summer sky is very blue and the summer clouds are white and beautiful.

In autumn, there are always some dark clouds in the sky as if it is going to rain, and the weather is cooler in autumn, and the dark clouds in the sky are colorful through the light, and you can enjoy a very beautiful dusk in autumn.

Although the winter sky is not as good as spring, summer and autumn, it has its own color, the light blue snow is unusually beautiful, and the winter wind is not strong but quite biting.

In autumn, in the Northern Hemisphere, the sun gradually changes from direct hitting the ground around the summer solstice (June 21 of the solar calendar) to oblique rays, and the daytime time gradually becomes shorter, and the night time gradually increases. In autumn, the ground absorbs less heat from the sun than in summer, and the moisture evaporated from the ground into the air also decreases, so that there are fewer clouds in the sky, and even if there are clouds, it is a faint layer, and the visibility is very good, forming a blue sky scene, so the autumn sky looks so high!

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.