Climate change before and after the great cold solar terms

The Great Cold is the last solar term among the 24 solar terms and the last solar term in winter, which is just worth 49. As the saying goes, there is a great cold every year, not March 9 but April 9, and the weather is still dominated by cold. The great cold solar term is a festival reflecting climate change, and it is colder in the great cold season, which is the general law of climate change. Before and after the slight cold to the severe cold, the heat emitted from the ground surface reached its peak, so it was said that the cold was in March 9th.

Citing the explanation of "Giving Time to Pass the Examination" in Three Rites and Righteousness, it is called Great Cold because the great cold is the middle and the upper form is slight cold. . The extreme inversion of cold is called great cold. It is said that a cold is a cold. This festival is the coldest period of the year during March 9 and April 9, when cold waves frequently go south. There is a folk saying that mild cold is the most important thing, and no wind is cold. Great cold refers to extremely cold weather. Although the winter solstice solar terms are the lowest in the northern hemisphere, the coldest time of the year is the slight cold and great cold solar terms after the winter solstice solar terms, especially the great cold solar terms.

This is because after the winter solstice, the direct point of sunlight will gradually move northward, but in the following time, the direct point of sunlight will always be in the southern hemisphere, and the heat in the northern hemisphere will always be lost, and the heat absorbed during the day is still less than the heat released at night. Therefore, after the winter solstice, the temperature in the northern hemisphere will continue to decrease, with the lowest temperature during the severe cold solar term, which is the coldest solar term in a year.

Because China has a vast territory and a large span between the north and the south, the climate between the north and the south is quite different. According to China's long-term meteorological records, there is no slight cold in the great cold solar terms in the northern region; But for most parts of the south, April and September are the coldest, so the big cold solar terms are colder than the small ones. Slight cold and severe cold are the periods with the least rainfall in a year. During the annual cold solar term, the rainfall in South China is only 5 to 10 mm. ..

Is the Great Cold Solar Term the coldest solar term? The great cold is actually the coldest day of the year. In fact, from the statistical data, the slight cold is the lowest temperature in a year most of the time. Average temperature: According to the average temperature during the 195 1-20 16 solar term in China, the average temperature of the mild cold solar term in China is -5.6℃, and the average temperature of the severe cold solar term is -4.9℃. Time distribution: 195 1-20 16 In these 66 years, 27 years were slightly cold and cold, and 19 years were severely cold and cold. Spatial distribution: in most areas north of the Yellow River, the average minimum temperature during severe cold solar terms is lower than that during slight cold solar terms; In the area between the Yangtze River and the Yellow River, the severe cold is comparable to the slight cold; In the south of the Yangtze River, the slight cold solar terms are colder than the severe cold solar terms.

Because in recent years, the Great Cold Festival is full of joy and joy. In this solar term, people are busy saying goodbye to the old and welcoming the new, pickling new year's dishes and preparing new year's goods, because the Spring Festival, the most important festival for China people, is coming. After the great cold, a new round of solar terms will begin. Let's continue to work hard to greet the New Year bell.