The origin of the four seasons of the year

The earth's orbit around the sun is elliptical and has an angle with the plane of its rotation. When the earth is in different positions in its orbit at different times of the year, different places on the earth receive different sunlight and different heat from the sun, so there are seasonal changes and differences between cold and hot.

In climate, the four seasons are distinguished by temperature. In the northern hemisphere, March to May is spring, June to August is summer, September to165438+1October is autumn, and12-February is winter. In the southern hemisphere, the time of each season is just the opposite of that in the northern hemisphere. It is summer in the southern hemisphere and winter in the northern hemisphere; It is winter in the southern hemisphere and summer in the northern hemisphere. There is no obvious boundary between seasons, and the change of seasons is gradual.

The four seasons on the earth are first manifested as an astronomical phenomenon, which is not only the periodic change of temperature, but also

Periodic changes of the length of day and night and the height of the sun in spring. Of course, the change of the length of day and night and the height of the sun at noon determines the change of temperature. The gradual changes of the four seasons are not uniform all over the world. It is summer in the northern hemisphere and winter in the southern hemisphere. The northern hemisphere changes from warm to cold, and the southern hemisphere changes from cold to hot.