The origin of "the eagle is a sacrificial bird, the heavens and the earth are flat, and the grain climbs high"

Starting from the twenty-four solar terms in summer. Twenty-four solar terms are the earliest calendar in China that combines astronomy, meteorology and phenology to guide agricultural activities. It originated in the Yellow River valley and was completely recorded in the Book of Yizhou Shi Xun Jie in the 2nd century BC.

Take five days as days, three days as qi, six days as hours, four days as years, and twenty-four solar terms * * * seventy-two days a year. Each climate corresponds to a phenological phenomenon, which is called climate response.

Among them, the summer heat is divided into three stages: "One stage is that the eagle is a sacrificial bird; Second, wait for the beginning of heaven and earth; Three Hou Wonaideng. " In this solar term, eagles began to prey on birds in large numbers; Everything between heaven and earth began to wither; "Henaideng" refers to millet, millet, rice and sorghum crops, and "Deng" means maturity.

Extended data:

Weather characteristics in summer.

1, temperature drop

It is not enough to describe the solar terms in summer simply by the beginning of temperature drop. Temperature drop is just one of the phenomena.

The reasons behind this phenomenon are as follows: first, the direct point of the sun continues to move southward, and the solar radiation weakens; Second, the subtropical high moved southward by leaps and bounds, and the Mongolian cold high began to itch to try, punching and kicking, showing its edge.

2. Autumn is crisp

Under the control of the cold high pressure that began to affect our country, the sinking and dry cold air first announced the end of the rainy season in Northeast China, North China and Northwest China, and took the lead in starting the best weather in a year-crisp autumn.

In summer, only the northeast and northwest regions really enter autumn. But whenever cold air affects China, if the air is dry, it will often bring windy weather, and if there is warm and humid airflow in the atmosphere, it will often form a decent autumn rain. After every storm, especially after the rain, people will feel more obvious cooling. So there is a saying: "an autumn rain (wind) is a cold."

There may be a large precipitation process in the north and south Jianghuai areas. The temperature dropped significantly, and the temperature difference between day and night increased. It is sunny after the rain, and people often don't adapt to the cold and hot changes at the turn of summer and autumn. If you are not careful, it is easy to cause diseases such as respiratory tract, gastroenteritis and cold.

3. autumn tiger

Although the subtropical high, which is dominant in summer, strides south, it will never give up its advantage easily and retreat to the sea of the western Pacific easily. In the southern region under its control, people who just feel a little bit cool in autumn often feel hot weather at the end of summer, which is a veritable "autumn tiger".

Reference source: Baidu Encyclopedia-Chu Shu