Why does the cold wave of beginning of spring solar terms represent "beginning of spring"?

According to modern meteorological standards, beginning of spring is ahead of schedule, but it is actually welcoming spring.

"Spring rain surprised spring clear valley days, summer full mans summer heat connected. Autumn frost, winter snow. " This song "solar term song", which is well known to China people, implies the order of the 24 solar terms.

Twenty-four solar terms are a knowledge system and social practice formed by China people by observing the movement of the sun for a year and understanding the changing laws of the four seasons, climate and phenology in a year. The ancients in China divided the sun's annual trajectory into 24 equal parts, each of which was divided into a solar term, and each solar term had three cycles, each of which was five days. Twenty-four solar terms have been used for more than two thousand years since the Qin and Han Dynasties, guiding traditional agricultural production and daily life, and are an important part of China's traditional calendar system and related practical activities. In the field of international meteorology, this time cognition system is known as "the fifth invention of China".

"The dividing line between beginning of spring and China in winter and spring (when the average daily temperature reaches 10 degrees Celsius for five consecutive days, it is counted as spring), from Guilin, Guangxi to Ganzhou, Jiangxi. In the area south of this line, beginning of spring sometimes smells like spring, but 93% of the land in China is still winter, while in Heilongjiang, it is often long summer and spring, and in Grain Rain. The so-called beginning of spring is just a' conception'. "

The beginning of spring, which we determined in ancient times, is marked by the thawing of the east wind; The sign of the beginning of winter is that water begins to freeze. So the ancients used freezing and thawing to define winter and spring. However, according to modern meteorological standards, beginning of spring is ahead of schedule, but it is actually welcoming the Spring Festival. "He said that a similar example is beginning of autumn." beginning of autumn ranks third in the solar terms. As far as heat is concerned, it is still' cow' than the summer solstice, and the new autumn is often far away. "

The ancient book Qunfangpu explains beginning of spring as follows: "The foundation has also been established. Spring began and was established. " China traditionally divided the 65,438+05 days in beginning of spring into three periods: "When the east wind thaws, when the stinger starts to vibrate, and when the fish is frozen." In spring, the temperature began to rise, and sunshine and rainfall began to increase. But for most parts of the country, this is just a prelude to spring.

It has been thousands of years since beginning of spring ushered in spring. In ancient beginning of spring, Emperor Tiandi led three officials, nine ministers, princes and doctors to the eastern suburbs to welcome the Spring Festival and pray for a bumper harvest. The customs of solar terms in beginning of spring include welcoming the new year, spring outing, whipping spring cattle and biting spring.

The 24 solar terms still have various cultural meanings and social functions.