First, a brief introduction
1, Winter Solstice, also known as Solstice, Winter Festival, Sub-Year, etc., has two major connotations of nature and humanity. It is not only an important solar term among the 24 solar terms, but also a traditional folk festival of ancestor worship in China. The winter solstice is one of the four seasons and eight festivals, which is regarded as a big holiday in winter. In ancient times, there was a saying that the winter solstice was as big as a year.
2. The custom of winter solstice is different in content or detail because of different regions. In southern China, there is the custom of offering sacrifices to ancestors and feasting on the winter solstice. In the northern part of China, it is a custom to eat jiaozi every winter solstice.
Second, the specific situation
1, Winter Solstice is the 22nd solar term of the "Twenty-four Solar Terms", with the solar meridian reaching 270 degrees, and it meets on the Gregorian calendar1February 2 1-23 every year. The winter solstice is the extreme point where the direct sunlight travels southward. On the winter solstice, the sun shines directly on the Tropic of Capricorn, and the sun is most inclined to the northern hemisphere, and the solar altitude angle is the smallest. It is the shortest day and the longest night in all parts of the northern hemisphere.
2. Winter Solstice, that is, the turning point of the point of direct sunlight returning to the north. After this day, it will go back, and the point of direct sunlight will start to move northward from the Tropic of Capricorn (23 26' s), and the daytime in the northern hemisphere (China is located in the northern hemisphere) will increase day by day. On the winter solstice, although the sun is low and the day is short, the temperature of the winter solstice is not the lowest in meteorology.
3. In fact, because there is still "accumulated heat" on the surface, it is usually not very cold before the winter solstice, and the real cold is after the winter solstice. Because of the great difference in climate in different parts of China, this climatic winter is obviously late for most parts of China. The winter solstice marks the beginning of the cold season, and the people begin to count nine to calculate the cold days.
Third, phenological phenomena
1, some ancient literary works in China divided the winter solstice into three phases: "One phase is earthworm knot; Second, wait for the elk horn solution; Waiting for the water to spring. " It means that the earthworm in the soil is still curled up, and the elk feels the yin gradually retreating and getting rid of the angle.
2. As the direct point of the sun returns to the north after the winter solstice, the sun moves back and forth into a new cycle, and the height of the sun rises from then on, and the day grows day by day, so the spring water in the mountain can flow and be warm at this time.