Twenty-four solar terms formula

Section 24: Spring rains shake the valley in spring, and summer is full of mountain heat. Autumn dew, autumn frost, little snow in winter and cold in winter.

24 solar terms Table is a list of 24 specific festivals in China calendar, and each solar term has its own unique meaning. It accurately reflects the change of natural rhythm and plays an extremely important role in people's daily life.

The twenty-four solar terms were originally formulated according to the changes of stars. The Big Dipper rotates circularly, and bucket handle rotates clockwise once, which is called one of the "years old". At present, the establishment of the twenty-four solar terms is based on the "annual apparent movement of the sun", which is also the degree of the yellow meridian of the sun. Although they are established in different ways, the cause of the struggle is that the earth revolves around the sun, so the time of their intersection is basically the same.

"Twenty-four solar terms" is the product of ancient farming civilization, and farming production is closely related to the rhythm of nature. It is a knowledge system formed by ancient ancestors following the farming season and observing the movement of celestial bodies to understand the changing laws of seasons, climate and phenology in a year. Each solar term represents different changes in climate, phenology and time. In the historical development, the 24 solar terms have been incorporated into the lunar calendar and become an important part of the lunar calendar.

Rainwater solar terms:

Rain is the second of the 24 solar terms. Fight with your fingers; The sun reaches longitude 330; February 18-20 of the Gregorian calendar every year. Rain, like solar terms such as Grain Rain, Xiaoman, light snow and heavy snow, is a solar term reflecting precipitation and ancient farming culture. Rain solar term means that it begins to rain, and the rainfall level is mainly light rain or Mao Mao rain.

Proper precipitation is very important for the growth of crops. Entering the rainy solar term, the northern part of China is still cloudy and cold, and it is still snowing in some places, and there is no breath of spring; Most places in the south are full of spring, with a scene of early spring.

The rain solar term generally starts from February 18 to 20 and ends on March 4 or 5. The rainy season is changeable, which is one of the seasons with the most cold wave processes in the whole year, with cold and hot, warm and cold at first. In the rainy season, the direct point of the sun gradually approaches the equator from the southern hemisphere.

At this time, in the northern hemisphere, the sunshine hours and intensity are increasing, and the temperature is rising rapidly. Warm and humid air from the ocean becomes active, and gradually pushes northward to meet with cold air to form rainfall, but the rainfall level is mainly light rain or Mao Mao rain.