The next solar term of cold dew is the first frost, which is one of the 24 solar terms. Every year around 65438+1October 23rd in Gregorian calendar, the first frost solar term means that the weather is getting colder and the first frost appears, which is the last solar term in autumn and also means the beginning of winter. Health care is particularly important in the first frost season. There is a folk proverb that "it is better to make up the first frost one year", which shows the influence of this solar term on us.
One of the 24 solar terms of the first frost, the weather is getting colder and frosty. The first frost usually occurs on the 23rd day of the Gregorian calendar 10 year 10. At this time, the first frost appeared in the Yellow River basin in China, and most areas were busy planting crops such as three wheat.
In ancient China, the first frost was divided into three stages: "One stage was that the jackal sacrificed animals; Second, the vegetation is yellow; Three waiting insects are salty. " In this solar term, jackals will show their prey before eating them.
The first frost occurs when the sun reaches the longitude of 2 10 degrees every year around Gregorian calendar 10 year10 23rd. The first frost said that the weather was colder and the dew condensed into frost. "Twenty-four solar terms": "In mid-September, the essence is cold and condensed, and dew cream". At this time, frost has appeared in the Yellow River Basin of China, and a silver ice crystal shines in the fields thousands of miles away. At this time, the leaves turned yellow and fell. The ancient book "Twenty-four solar terms" says: "When the frost comes, the yin begins to coagulate." It can be seen that "first frost" means that the weather is getting colder and it begins to frost. Meteorologically, the first frost in autumn is generally called "first frost" or "first frost", and the last frost in spring is called "late frost" or "final frost". The interval from the last frost to the first frost is a frost-free period. Some people also call the first frost "Chrysanthemum Frost", because chrysanthemums are in full bloom at this time, and Su Shi, a great writer in the Northern Song Dynasty, said in a poem: "All trees are sweeping away pornography, and only Furong is alone."
Frost is formed by condensation of water vapor. How can water vapor condense into frost? Lv Benzhong, a poet in the Southern Song Dynasty, wrote in Luzi IV in the Southern Song Dynasty: "The moon invades the post, and the bridge spends the night frost." Lu You wrote in Frost Moon that "the withered grass is frosty and gray, and the cold window is full of new shadows." It shows that frost appears on a clear moonlit night in autumn. There are no clouds in the autumn night, and the ground is like a quilt, which radiates a lot. When the temperature suddenly drops below 0℃, the water vapor on the ground will condense on streams, bridges, leaves and soil, forming tiny ice needles, and some will become hexagonal frost flowers. Frost can only form on sunny days. People say that "the thick frost is fierce" is the reason.
Every year around Gregorian calendar 10 year 10, when the sun reaches the longitude of 2 10 degrees, it is the first frost in the 24 solar terms. The first frost is the last solar term in autumn, which is the transition from autumn to winter. There is a lot of heat dissipation on the ground in autumn, and the temperature suddenly drops below 0 degrees. Water vapor in the air directly condenses on the ground or plants to form fine ice needles, and some become hexagonal frost flowers, which are white and loose in structure.
"Twenty-four solar terms" said that the first frost: in mid-September, the gas was cold and condensed, and the dew became frost. "First frost" means that the weather is getting colder and the dew condenses into frost. In ancient China, the first frost was divided into three stages: first, the jackal sacrificed animals; Second, the vegetation is yellow; Three stings are salty. The jackal began to catch prey, sacrifice animals, and return books to heaven with animals, paving the way for sacrificing autumn gold; The leaves on the earth turned yellow and fell; The stinging insects are motionless in the cave and hang their heads into hibernation.