How to correctly understand the relationship between solar terms and 24 solar terms?

The vernal equinox is one of the 24 solar terms and the fourth solar term in spring. The longitude of the sun reaches 0, and the festival is held on March 19-22 of the Gregorian calendar every year. "Equinox" has two meanings. One is "season sharing". Traditionally, spring is between beginning of spring and Changchun, and the vernal equinox is in the middle of the two solar terms, which just divides spring equally. Another meaning is "equal day and night". At the vernal equinox, the sun shines directly on the equator, and the length of day and night is equal, each being 12 hour.

(Source: China Meteorological News)

Weather characteristics of vernal equinox

After the vernal equinox, China has entered a beautiful spring except the Qinghai-Tibet Plateau, Northeast China, Northwest China and North China. The vernal equinox is of great significance in astronomy. On the day of the vernal equinox, the sun shines directly on the equator, and the northern and southern hemispheres are divided equally day and night. Since then, the direct position of the sun has continued to move from the equator to the northern hemisphere. In the northern hemisphere, the day begins to be longer than the night, while in the southern hemisphere, it is the opposite.

The average daily temperature in all parts of China has steadily increased to above 0℃ except the mountainous areas in winter and the areas north of 45 north latitude. At this time, the severe cold has passed, and the temperature rises rapidly, especially in North China and Huanghuai Plain, where the daily average temperature has risen above 10℃. After the vernal equinox, the precipitation in the south of the Yangtze River increased rapidly and entered the period of "peach blossom flooding" in spring.

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During the vernal equinox, dusty weather will follow. According to the statistics of dusty weather in recent years, April is the most frequent, followed by March, and the vernal equinox is 15 days, that is, from the end of March to the beginning of April. As the saying goes, "Spring rain is as expensive as oil." There is little rain and dry weather at this stage. Once there is a strong wind, it is easy to roll up dust and form dusty weather.

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Three stages of vernal equinox

Wait a minute, the mysterious bird is coming. The mysterious bird arrived: Ye Yan, the mysterious bird, coaxed and said, "The vernal equinox comes and the autumn equinox goes."

Second, Lei Nai speaks. The thinness of yin and yang is thunder. At this time, the four yang are gradually flourishing, and there is still yin, so it is thin and sound; Yes, the rhyme club said, "It is difficult to exhale like gas." Shu Zhu said: "hair, still out."

Third, power on. Electricity, sunshine also; The four yang are flourishing, and the gas is exhausted and the light is born. Therefore, "Li Jie" said: "All voices are positive; It's just yang. " "Yi" said: "Thunder and lightning are combined into one chapter. "The Biography of the Ram also said," Electricity, Lei Guang. "Yes, Xu said," Thunder is the sun and electricity is the yin. "Not really. It is obvious that there is electricity without thunder in midsummer.

Vernal equinox agricultural activities

As the saying goes, "The spring equinox begins with wheat, and the fat and water should follow". A spring rain was warm. After the spring rain, I was busy plowing. The busy farming season in spring is about to begin, and spring management, spring ploughing and spring planting are about to enter a busy stage. After the vernal equinox, overwintering crops enter the growth period, so field management should be strengthened. Because the temperature rises rapidly and the water demand is relatively large, farmers should strengthen water storage and moisture conservation.