Astronomical characteristics of the twenty-four solar terms

What does the twenty-four solar terms mean? What are the characteristics of the 24 solar terms?

Beginning of spring in 24 solar terms: Dou refers to the Northeast. The meridian of the sun is 3 15 degrees. It is the first of the 24 solar terms. It means to begin to enter the spring, "yang and thorns, everything is spring." After beginning of spring, everything is full of vitality, and the four seasons begin now.

Rain: finger fights. The meridian of the sun is 330 degrees. At this time, the spring breeze blows all over, the ice and snow melt, the air is moist, and the rain is increasing, so it is called rain. People often say: "Spring blossoms, and rain is busy to send fertilizer."

Stunned: fight with your fingers. The meridian of the sun is 345 degrees. This solar term means that after beginning of spring, the weather gets warmer, the spring thunder starts to shake, and all kinds of hibernating animals that are dormant in the soil will wake up and start to move, so it is called a fright. During this period, the eggs laid by overwintering insects will also begin to hatch. Some parts of China have entered the spring ploughing season. As the saying goes, "After being shocked, it is warm and harmonious, and the old toad sings folk songs." "I was startled by a plow, and the vernal equinox was full of air." "Before the thunder comes, the rain is like a dragon."

Vernal equinox: fighting refers to shackles. The meridian of the sun is 0 degrees. The sun is above the equator at the vernal equinox. This is the 90-day vernal equinox of spring. On this day, the northern and southern hemispheres are equal in day and night, so it is called the vernal equinox. After this day, the direct position of the sun moves northward, and the days in the northern hemisphere are long and the nights are short. So the vernal equinox is the beginning of spring in the northern hemisphere. Overwintering crops in most parts of China have entered the spring growth stage. Agricultural proverbs in various places include: "The spring equinox comes first, and rice competes for money" (Guangdong), "The spring equinox never stops raining, but the summer equinox never stops burning" (Sichuan), "When it rains, every family is busy, planting melons and beans first, then transplanting them" (Hubei), "Planting vegetables at the spring equinox, picking melons in summer" (Hunan) and "Planting beans at the spring equinox, and planting them at the autumn equinox.

Qingming: fighting refers to Ding. The solar calendar is 15. At this time, the climate is refreshing and warm, flowers and trees grow new branches, everything begins to grow, and farmers are busy ploughing and planting in spring. Once upon a time, on this day in Tomb-Sweeping Day, some families would plant willows at the door and go for an outing to sweep the graves in the suburbs. This is an ancient custom.

Grain Rain: There's a fight. The meridian of the sun is 30 degrees. It means that rain breeds grain. Because rain nourishes the earth, grains can grow, so Grain Rain is "rain gives birth to hundreds of grains". As the saying goes, "Before and after Grain Rain, you reap what you sow".

Long summer: the bucket refers to the southeast. The meridian of the sun is 45 degrees. Now it's long summer, and since then, everything has flourished. Traditionally, the long summer is regarded as an important solar term for the temperature to rise significantly, the summer heat is approaching, thunderstorms are increasing, and crops enter the peak season.

Little Man: Fighting nails. The meridian of the sun is 60 degrees. Since Xiaoman, summer crops such as barley and winter wheat have borne fruit and full seeds, but they are not yet mature, so they are called Xiaoman.

Mangzhong: Beidou points to itself. The meridian of the sun is 75 degrees. At this time, it is most suitable for sowing grain crops with awns, such as late rice, millet and millet. If you plant awns and crops after this time, it will not be ripe. At the same time, "awn" refers to crops with awns such as wheat and barley, and "species" refers to seeds. Awn seeds indicate the maturity of awned crops such as wheat. Before and after the awning, the rainfall in the middle and lower reaches of the Yangtze River in Central China increased and the temperature rose. In the rainy season, the air is very humid, the weather is extremely sultry, and all kinds of utensils and clothes are prone to mildew, so it is also called "mildew rain" in the middle and lower reaches of the Yangtze River in China.

Summer solstice: Beidou points to B. The meridian of the sun is 90 degrees. When the sun is at the "Summer Solstice Point" at 90 degrees of the yellow meridian, it is almost directly above the Tropic of Cancer, and the sun is the highest in the northern hemisphere at noon. This day is the longest day and the shortest night in the northern hemisphere. From this day on, it entered the hot season, when everything in the world grew most vigorously. In ancient times, the heart also called this day the northern solstice, meaning the northernmost day when the sun was born. After the summer solstice, the sun gradually moves southward, and the days in the northern hemisphere become shorter and the nights become longer.

Summer heat: fighting refers to Xin. The solar calendar is 105. It's already very hot, but it's not hot enough, so it's called Xiaoshu. At this point, it is already around the beginning.

Summer: bucket refers to C. solar meridian 120. The summer heat is the hottest solar term in a year. Before and after the next day's duty, high temperature weather of 40℃ often appeared in many places in the Yangtze River Basin. Do a good job in heatstroke prevention and cooling. There is a lot of rain in this solar term, so we should pay attention to the flood control and waterlogging prevention in the proverb "little summer heat, big summer heat, drowning rats"

Beginning of autumn: Beidou points southwest. The solar line is 135. From this day on, autumn began, the autumn was crisp, the moon was bright and the wind was clear. Since then, the temperature has gradually decreased from the hottest time.

Summer heat: fighting refers to five. The solar line is 150. At this point, the heat has come to an end. The heat of summer is about to dissipate. This is the turning point of the temperature drop. It is a symbol of cold climate and indicates the end of summer.

Millennium: Fingers pointing. The solar line is 165. When the weather turns cold, the ground water vapor condenses the most.

Autumnal equinox: the barrel refers to itself. The solar line is 180. On the day of the autumnal equinox, like spring people, the sun is almost direct to the equator, and day and night are almost equal. From this day on, the position of direct sunlight continued to move from the equator to the southern hemisphere, and the days became shorter and the nights became longer in the northern hemisphere. According to China's autumnal equinox theory, this day is exactly half of the ninety days in autumn, so it is called autumnal equinox. But in astronomy, it is stipulated that autumn in the northern hemisphere begins with the autumnal equinox.

Cold dew: fighting nails. The solar line is 195. After the white dew, the weather turned cold and dew began to appear. When the dew is cold, there is much dew and the temperature is low. So some people say that cold is dew, white first and then cold, which means that the climate will gradually turn cold. Water vapor condenses into dew.

First frost: solar longitude 2 10. It's already cold, and there is frost, so it's called the first frost.

Beginning of winter: The longitude of the sun is 225 degrees. Traditionally, our people think that this day is the beginning of winter. Winter, as the end, means that after a year of field work, crops will be harvested. After beginning of winter passes, the middle and lower reaches of the Yellow River in China will soon freeze, and farmers from all over China will gradually turn to farmland water conservancy infrastructure and other agricultural activities.

Xiaoxue: The longitude of the sun is 240. The temperature dropped and it began to snow, but it was not the season of heavy snow, so it was called light snow. Before and after the light snow, it began to snow in the Yellow River basin (snowfall in the south is two solar terms later); In the north, it has entered the freezing season.

Heavy snow: solar longitude 255. Before and after the heavy snow, there was gradually snow in the Yellow River basin. In the north, it's already the severe winter of "thousands of miles frozen, Wan Li snowing".

Winter solstice: the longitude of the sun is 270 degrees. On the solstice of winter, the sun shines almost directly on the tropic of Capricorn. Our northern hemisphere has the shortest day and the longest night, and it has begun to enter several cold days. Astronomy stipulates that this day is the beginning of winter in the northern hemisphere. After the winter solstice, the direct sunlight gradually moved northward, and the days in the northern hemisphere gradually became longer. As the proverb goes, eating noodles on the solstice in winter will make the day longer.

Slight cold: solar calendar 285. After the slight cold, it began to enter the cold season. Cold air is cold for a long time, and slight cold means that the weather is cold but not extreme.

Great cold: the longitude of the sun is 300. Great cold refers to extremely cold weather. Around the Great Cold is the coldest season of the year. The great cold occurred just after March 9 and at the beginning of April 9. As the saying goes, "three, nine, four and nine don't do it."