How are the four seasons formed?

All the year round is formed because the earth revolves around the sun.

The temperature of a plane on the earth is related to whether sunlight is direct or oblique. When a beam of fixed size is aimed at a plane, the spot will be a perfect circle, while when it is tilted, the spot will be an ellipse. The more tilted the ellipse is, the more light energy will shine on a larger area.

It can be understood that the heat per unit area of the spot area is less in the oblique direction and more in the vertical direction. Therefore, the temperature is higher in direct sunlight and lower in oblique sunlight.

Temperature is the main factor that determines the season, so the place where the sun shines directly is summer, the place where the oblique light is most severe is winter, and the place between them is spring or autumn.

Extended data

On March 2 1 day, when the earth revolves to the position of 0 degrees of the yellow meridian, the sun shines directly at the equator. At this time, the sun in the northern and southern hemispheres is oblique, and the temperate zone in the northern hemisphere is vernal equinox, not spring. The temperate zone in the southern hemisphere is the autumnal equinox, not autumn.

Around June 22, when the earth turns to the 90-degree position of the yellow meridian, it is also the farthest time between the earth and the sun, which is called the distant sun. The sun shines directly on the Tropic of Cancer (23 degrees and 26 minutes north latitude), and the summer solstice in the northern hemisphere enters the summer in the temperate zone of the northern hemisphere. The temperate zone in the southern hemisphere is winter solstice, and the temperate zone in the southern hemisphere enters winter.

On September 23rd or so, when the earth turns to the position of longitude 180, the sun shines directly on the equator, the northern hemisphere is the vernal equinox, and the temperate zone in the northern hemisphere enters autumn. The southern hemisphere is the vernal equinox. The southern hemisphere enters spring.

On February 22, 65438+, when the earth turned to the position of 270 degrees of the yellow meridian, it was also the closest place between the earth and the sun, which was called perihelion. The sun shines directly on the Tropic of Capricorn (23 degrees and 26 minutes south latitude), and the southern hemisphere enters summer from summer solstice. During the winter solstice in the northern hemisphere, the temperate zone enters winter.

Next, we will enter a new year, and a new round of four seasons will begin again.

References:

Baidu encyclopedia-all the year round