The causes of the four seasons

The causes of the four seasons are the result of the earth's revolution and rotation, the periodic reflection of climate change, and the natural phenomenon produced by the earth's revolution around the sun on the equatorial plane.

The revolution of the earth refers to the elliptical motion of the earth around the sun, which is completed once a year. When the earth moves around the sun on the ecliptic, it is called the equatorial plane. At this time, the sun shines directly on the equator, and the sunshine time in the northern hemisphere and the southern hemisphere is the same, and the temperature is suitable, which is called vernal equinox and autumn equinox.

When the earth's revolution is closest to the sun, the southern hemisphere will get more direct sunlight, which leads to the climate difference between the northern hemisphere and the southern hemisphere. This is the summer solstice, with the longest day and the shortest night in the northern hemisphere. When the earth revolves to the farthest position from the sun, the southern hemisphere will be far away from the sun, which will lead to the climate difference between the northern hemisphere and the southern hemisphere. This time is the winter solstice.

In addition, the change of the inclination of the earth's axis is also an important reason for the periodic change of the four seasons. The earth is not upright, but inclined. The angle between its axis and the ecliptic plane is about 23.4 degrees, which leads to the change of the four seasons. When the earth rotates, the direct angle of the sun received by the northern and southern hemispheres is constantly changing, which leads to the changes of temperature, rainfall and sunshine time.

Introduction to the four seasons:

Spring is usually from the beginning of March to the end of May, and it is the warmest and wettest season among the four seasons. The temperature rises gradually, green leaves of plants sprout and flowers bloom. The scenery in spring is mainly green, and there is a fresh, refreshing and vibrant feeling everywhere. Spring is a good time for people to go out for picnics, picnics and flowers.

Summer is usually from the beginning of June to the end of August, and it is the hottest season of the year. The temperature is high during the day, cool at night, and there are often thunderstorms. The scenery in summer is mainly green, all kinds of flowers are in full bloom in this season, and rivers and lakes have become a good place for swimming and water sports. Summer is also a good time for people to spend their holidays and travel.

In autumn, from the beginning of September to the end of 1 1, the temperature gradually decreases, and it is cool during the day and slightly cold at night. Autumn scenery is dominated by red, yellow and gold, and maple, ginkgo, osmanthus and other plants have begun to lose color and become golden. Autumn is one of the characteristics of autumn. Autumn is a good time for people to enjoy the scenery, pick and climb mountains.

Winter generally lasts from the beginning of 12 to the end of February, which is the coldest season among the four seasons, with short days and long nights. The scenery in winter is mainly white, with snowflakes falling and snow-covered, giving people a pure and beautiful feeling. If there is snow, winter is also a good time for people to ski, have snowball fights and other ice and snow activities. At the same time, winter is also the season when people get together to celebrate festivals.