Characteristics of cold dew solar terms

Cold dew is the seventeenth of the twenty-four solar terms and belongs to the fifth solar term in autumn. Finger e; Longitude of solar arrival195; Celebrate every year from July 7th to 9th in Gregorian calendar 10 year 10. Cold dew is a solar term that reflects the characteristics of climate change and is a transition from cool to cold. Judging from the climate characteristics, Nanling and its vast northern areas have entered late autumn in the cold dew season, and the northeast and northwest regions have entered or are about to enter winter. "Twenty-four solar terms" said: "In September, the dew is cold and will condense." The meaning in the work is that the temperature is lower than that in the white dew, and the dew on the ground is cold and will soon condense into frost. The temperature drops gradually. In China, cold dew is traditionally regarded as a sign of cold weather. With the arrival of cold dew, the climate turns from hot to cold, and everything is born with cold and gradually falls. This is the season of alternating hot and cold. In nature, the qi of yin and yang begins to change, the yang is gradually declining, and the yin is gradually born. The physiological activities of the human body should also adapt to the changes in nature to ensure the physiological (yin and yang) balance in the body. Pay attention to health at this time. During the cold dew season, the temperature in most parts of South China continues to drop. The average daily temperature in South China is less than 20℃. Even in the areas along the Yangtze River, it is difficult for the temperature to rise above 30℃, while the minimum temperature can drop below 10℃. Except for a few valley lowlands, the five-day average temperature in the northwest plateau is generally lower than 10℃. According to the standard of dividing the four seasons by climatology, it is already winter, and first frost is thousands of miles away, which is quite different from the autumn colors in the south.

Cold dew is a solar term reflecting the characteristics of climate change. Cold dew, white dew and first frost all indicate the phenomenon of water vapor condensation, and cold dew is a transition from cold to cold. Compared with the white dew, the temperature drops a lot, and the dew on the ground is colder, which is likely to become frozen dew, so it is called cold dew. In ancient times, solar terms were divided by "bucket handle pointing method". When the bucket handle of the Big Dipper pointed in the E direction (that is, the northwest direction), it was a cold dew solar term. From the Han Dynasty to the end of the Ming Dynasty, solar terms were divided by the method of "balancing qi". At noon that day, the sun shadow was measured with a standard watch. The length of the sun shadow was eight feet two inches, which is equivalent to 2.0438+08 meters today. Since 1645, solar terms have been divided by the method of "fixing qi", and when the sun reaches longitude 195 degrees, it is cold dew. Generally speaking, the solar term of cold dew falls on the 8th or 9th of 10/0 of the Gregorian calendar every year.

Yuan Wucheng's "Twenty-four Solar Terms" said: "If it is cold in September, it will be condensed." The interpretation of cold dew in this work is that the temperature is lower than that of white dew, and the dew on the ground is colder and will soon condense into frost.

During the cold dew season, Nanling and the vast area to the north have entered the season and autumn, and the northeast and northwest regions have entered or are about to enter the winter. The first frost can be seen in most years in Beijing. In addition to the perennial snow on the Qinghai-Tibet Plateau, it has generally begun to snow in the northeast and northern Xinjiang.

The "calming qi method" used in ancient China divided the cold dew into three stages: "Waiting for the geese; Second, the sparrow enters the water and becomes a clam; Three chrysanthemums have yellow flowers. " In this solar term, geese move south in a line or herringbone queue; In the cold late autumn, all the birds disappeared. The ancients saw a large number of clams suddenly appearing on the seashore. The stripes and colors of shells were very similar to those of birds, and they thought they were birds. The third stage of "Chrysanthemum begins to blossom" means that the chrysanthemum has opened in a large area at this time.

After the cold dew, the dew increases and the temperature decreases. In China, cold dew is traditionally regarded as a sign of cold weather. The solar term of the Mid-Autumn White Dew is "dew condenses white", and it is already "dew cold, it will condense into frost" when it is cold in season and autumn. At this time, the temperature in most parts of South China continued to drop. The average daily temperature in South China is less than 20℃. Even in the areas along the Yangtze River, it is difficult for the mercury column to rise above 30℃, while the minimum temperature can be reduced to below 10℃. Except for a few valley lowlands, the five-day average temperature in the northwest plateau is generally lower than 10℃, which is already winter according to the standard of four seasons climate division. Thousands of miles away, first frost and Wan Li are snowing, which is very different from autumn in South China.