Introduction to the Great Cold Solar Terms

Introduction to the Dahan solar term

Dahan is the last solar term among the twenty-four solar terms throughout the year. Every year around January 20 of the Gregorian calendar, when the sun reaches 300° of ecliptic longitude, it is the Great Cold. Below is an introduction to the Great Cold solar term that I have collected and compiled. I hope it will be helpful to you!

Overview

"Collection of the Seventy-Two Hours of the Monthly Order": "In mid-December, the explanation is before seeing (Xiaohan)." "Time-telling Tong" "Kao·Tianshi" quoted "Sanli Yi Zong": "The big cold is the middle one, and the upper shape is better than the minor cold, so it is called the big... The cold air is the opposite extreme, so it is called the big cold." At this time, cold waves moved south frequently, which was a common phenomenon in some parts of China. During the coldest period of the year, the wind is strong, the temperature is low, and the snow on the ground does not melt, presenting a severe cold scene of ice and snow, and freezing temperatures. During this period, departments such as railways, posts and telecommunications, petroleum, power transmission lines, and water transportation must pay special attention to taking early measures to prevent disastrous weather such as strong winds, cooling, heavy snow, etc. In agriculture, it is necessary to strengthen the cold and frost protection of livestock and overwintering crops.

Origin

Dahan means extremely cold weather. The Great Cold is the last of the twenty-four solar terms in China. After the Great Cold, a new year of solar terms begins.

As the saying goes: "Flowers and trees are in season, and birds are singing to announce the farming season." Flowers, plants, trees, birds and animals all move according to the seasons, so their regular movements are regarded as important signs of distinguishing seasonal solar terms. In ancient China, the Great Cold was divided into three periods: "The first period is for chicken milk; the second period is for birds to be sick; the third period is for water and solid belly." That is to say, chicks can be hatched during the period of the Great Cold. However, hawks and other hawks are in a state of extremely strong hunting ability, hovering in the air in search of food to replenish their body's energy to withstand the severe cold; in the last five days of the year, the ice in the waters freezes to the point of freezing. In the center, it is the strongest and thickest. Children can enjoy skating on the river (it can only be carried out when the daily average temperature is below -5℃ for many consecutive days. This kind of activity generally occurs in the area north of the Yellow River). In addition, the flower trade winds that appear in the Great Cold are "the first season is daphne, the second season is orchids, and the third season is mountain alum (born in the Jiangnan area)". It can also be used as an important symbol to judge the Great Cold.

Characterization

During the Great Cold, the atmospheric circulation is relatively stable, and the circulation adjustment period is about 20 days. When this kind of circulation adjusts, large-scale rain, snow, and windy cooling often occur. When there is a long-wave ridge to the west of 80 degrees east longitude and a large coastal trough in East Asia, my country will experience persistent low temperatures under the influence of northwesterly airflow and the continuous replenishment of cold air. Like Xiaohan, Dahan is also a solar term that indicates the degree of cold weather. Although modern meteorological observation records show that in some areas of my country, the major cold is not as good as the minor cold, in some years and in a few coastal places, the lowest temperature throughout the year still occurs during the major cold solar term. Therefore, we should continue to protect crops from cold, and pay special attention to protecting livestock to survive the winter safely.

During the Great Cold season, the average temperature in most areas of southern China is 6°C to 8°C, which is nearly 1°C higher than that of the Lesser Cold. The proverb "Small cold and big cold are all cold", indicating that the big cold solar term is also a cold period of the year.

For some crops, appropriate low temperature is required during a certain growth period. Wheat and rapeseed, which have strong winter characteristics, require lower temperatures after passing through the vernalization stage, otherwise they will not be able to grow and develop normally. Most areas in southern China have warm winters all year round. Wheat and rapeseed sown too early often grow too vigorously, jointing and bolting in advance, and their cold resistance is greatly weakened, making them vulnerable to low-temperature frosts. It can be seen that selecting crop varieties according to local conditions, sowing and planting at the right time, and taking effective promotion and control measures are an important part of achieving high yields.

Small Cold and Major Cold are the periods with the least rain in the year. In the perennial Great Cold Season, the rainfall in most areas of southern China only increases slightly compared with the previous period. In most areas of southern China, the rainfall is 5 to 10 millimeters, and in the northwest plateau and mountains, rainfall is generally only 1 to 5 millimeters. South China has a dry winter. During this period of overwintering, water consumption is small, and the contradiction between supply and demand of farmland water is generally not prominent. However, "Don't complain about the rain and snow in the bitter cold. The snow will leave the wheat until next year." In the case of scarce rain and snow, timely irrigation in different regions according to different farming habits and conditions will undoubtedly be of great benefit to the growth of wheat crops. Cold waves frequently move southward during this period, which is a very cold period of the year in most parts of my country. Railways, post and telecommunications, petroleum, maritime transportation and other departments must pay special attention to taking early measures to prevent severe winds, cooling, heavy snow and other disastrous weather. In agriculture, it is necessary to strengthen the cold and frost protection of livestock and overwintering crops.

Knowledge on health preservation during the Great Cold Season

1. It is more appropriate to go to bed early and get up late. The Great Cold is the last solar term in winter. Therefore, it has some characteristics of winter, that is, the temperature is relatively low, and people are easily infected with wind cold. There is also a large temperature difference between morning and evening, and the days are still short and the nights are long. Therefore, the Great Cold The most important thing is to protect yourself from the cold. Sleeping too late will cause severe cold, and getting up too early will also make you very cold. Therefore, it is more appropriate to go to bed early and get up late. Going to bed early is to replenish the spirit and replenish the yang energy, while getting up later to avoid being too cold can replenish the yin energy.

2. Scald your feet with warm water before going to bed. People all have this experience. When their feet feel cold, their whole body feels cold, because there are many acupuncture points and meridians on the soles of the feet. Moreover, the feet are also peripheral parts, and poor circulation in the peripheral parts will definitely affect the whole body.

Therefore, it is very important to keep the feet warm and the blood flowing smoothly. Therefore, it is recommended to soak the feet in hot water before going to bed. This can dilate the blood vessels, accelerate the blood flow, improve the nutrition of the skin and tissue of the feet, and reduce muscle tension. It is good for preventing frozen feet and Disease prevention and health care are beneficial, and because warm feet can also promote better sleep and improve sleep quality, many people like to read and write at night. People with this habit should soak their feet in hot water before going to bed.

3. Go out for exercise after the sun comes out. Try not to "dance after smelling chicken" during winter sports. Firstly, the air pollution is very serious nowadays. Morning is usually the time when the smog is most serious. Exercising too early will damage the health of our lungs. Secondly, morning is the time when turbid air rises. Exercising early in the morning is not only bad for your health, but can also hurt your body. Therefore, the best time to exercise is after the sun comes out. If the weather is good and there is no haze, you can enjoy outdoor exercise.

4. Replenishing the kidneys is the key point. In terms of diet, the main thing is to pay attention to nourishing and tonifying the kidneys. According to the theory of the Huangdi Nei Jing, winter is the kidney among the five internal organs, so kidney nourishing is still the focus in this season. In addition to eating more kidney-nourishing foods, you should also pay attention to the diet not being too salty, because too much salt will damage the kidneys. Therefore, the diet in the Great Cold is mainly low-salt and light. It is recommended to eat more beans and drink more porridge and various kidney-nourishing soups, because porridge and soup are very easy to digest and absorb, and there is no need to add too much salt.

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