Brief introduction to the origin of severe cold solar terms

1, Great Cold is the last of the 24 solar terms. Every year around 65438+10.20, when the sun reaches 300 degrees of the yellow meridian, it is called "Great Cold". Great cold refers to extremely cold weather. "Give the time to pass the exam, the weather" quotes "Three Rites and Righteousness": "Great cold is the middle, and the upper form is slight cold, so it is called big? It is extremely cold, which is called great cold. "

At this time, the cold wave frequently goes south, which is the cold period in most parts of China in a year. The wind is strong, the temperature is low, and the snow on the ground does not melt, showing a cold scene of ice and snow. In ancient China, the Great Cold was divided into three stages: "One stage is chicken milk; Second, the symptoms of bird disease; Three times, the water is strong. " In other words, in the great cold solar terms, chicks can be hatched; Falcons such as eagles are in a state of strong predation ability, hovering in the air to find food to supplement their body energy to resist the cold; In the last five days of the year, the ice in the water has frozen to the center of the water, and it is the strongest and thickest.

3. The severe cold atmospheric circulation is stable, and the circulation adjustment period is about 20 days. When this circulation is adjusted, there will often be a wide range of rain and snow weather and strong winds to cool down. When the west of 80 degrees east longitude is a long wave ridge and East Asia is a coastal trough, under the influence of northwest wind flow control and constantly supplemented cold air, China will have a sustained low temperature.