Division of four seasons: 1. Astronomical standard
"Twenty-four solar terms" are actually calculated according to the solar calendar, that is, according to the 24 equal parts of the earth's orbit around the sun, not according to the lunar calendar (many people misunderstand).
Generally, 65438+ 10 is the hottest month in Leng Yue, and July is the hottest month, so people usually think that March, April and May of the solar calendar belong to spring. June, July and August belong to summer, and September, 65438+ October and 165438+ October belong to autumn. 65438+ February and the following year 65438+ October and February belong to winter. This division of four seasons generally accords with temperate regions with distinct four seasons.
From the astronomical phenomenon, the change of four seasons is the seasonal change of the length of day and night and the height of the sun. In a year, the season with long days and high sun is summer; The season with the shortest day and the lowest sun height is winter; The transitional seasons between winter and summer are spring and autumn.
According to the division standard of "four seasons" in modern astronomy, the vernal equinox (about March 2 1, 45 days compared with the Spring Festival Evening), summer solstice (about June 22), autumn equinox (about September 23) and winter solstice (about June 22) are four seasons.
China is a vast country, with thousands of kilometers between north and south. Therefore, it is the same season, but the temperature is very different. For example, in spring, Guangdong and Hainan in the southernmost part have put on summer clothes, while Heilongjiang, Inner Mongolia and Xinjiang in the northernmost part are still wearing cotton-padded clothes.
2. China ancient records.
In China folklore, beginning of spring (around February 4th), Changxia (around May 6th), beginning of autumn (around August 8th) and beginning of winter (around11.8th) in the "twenty-four solar terms" often serve as the beginning of the four seasons. Ancient folks also used to use the lunar month to represent the four seasons. The first month of the lunar calendar is spring, after April and May, it is summer (marked as Dragon Boat Festival in May), after July 7, it is autumn (marked as Double Ninth Festival on September 9), and after October, it is winter (called winter month). The first day of the first month is the first day of the year, also called the Spring Festival. This may be in line with the situation that the temperature in the Central Plains was late and warm when the "summer calendar" was formulated thousands of years ago, but it is no longer in line with the situation that the temperature dropped after two or three thousand years. For example, in the Xia, Shang and Zhou Dynasties, there were elephants and rhinoceroses in the Central Plains, and there were historical records of "plowing fields with elephants" and "using rhinoceros skins as armor". There is also a story of "Cao Chong calling himself an elephant" between Han and Wei Dynasties, but after Sui and Tang Dynasties, both elephants and rhinoceroses disappeared in the Central Plains.
Twenty-four solar terms are a summary of the long-term observation of astronomy, meteorology and phenology in Xia, Shang and Zhou Dynasties in China, which is a great achievement in the calendar. The division of the twenty-four solar terms has the characteristics of astronomy, meteorology and phenology. Its dichotomy to quartering (collectively referred to as eighth division) expresses astronomical data; The solar terms such as rain, fright, Qingming, Grain Rain, Xiaoman, Mang, Xiaoshu, Dashu, Chushu, Bailu, First Frost, Light Snow, Heavy Snow, Slight Cold and Severe Cold clearly show the climate and agricultural characteristics. Among them, great summer heat and great cold represent the hottest and coldest solar terms in a year respectively. Summer is the second qi after the summer solstice, that is, one month after the summer solstice, which is roughly equivalent to the middle volt in the traditional "three volts"; Great cold is the second breath after the winter solstice, that is, one month after the winter solstice, similar to the traditional "March 9". Therefore, there is a folk proverb: "Cold is in March 9th, while heat is in the middle." The astronomical phenomena are closely combined with the climate and have obvious characteristics. However, this division of four seasons is inconsistent with the actual climate situation in China in recent thousand years. For example, in beginning of autumn, beginning of spring, the traditional lunar calendar is the beginning of spring and autumn, but the climate is still in winter and summer; Summer solstice and winter solstice are traditionally regarded as the midpoint between summer and winter, but in climate, they are not the hottest and coldest times of the year.
According to the change of temperature and sunshine, it is popular to divide the four seasons into spring, summer, autumn and winter by astronomical solar calendar, that is, spring is from vernal equinox to summer solstice; Summer solstice to autumn is divided into summer; Autumn equinox to winter solstice is autumn; Winter solstice to spring is divided into winter. This standard of dividing seasons can reflect the general climate situation in the past thousand years, but it is not very accurate.
3. Standards proposed by climatologists in China.
It is simple and easy to remember to divide a year into four equal parts, but it is obviously impossible for crop growth and seasons to come sooner or later. In addition, the surface of China is still unevenly distributed with oceans, land, mountains and deserts. It is definitely not accurate to divide the seasons by a simple method of equal division.
1934, Zhang Baojun put forward a new standard of seasonal division combining phenology and agricultural production. He proposed to divide the four seasons by taking the five-day average temperature (waiting temperature) as the standard and taking into account the growth and activity laws of some plants or animals that can reflect the upcoming season. That is to say, when the average temperature (the average temperature for five consecutive days) drops below 10℃, winter begins, and when it rises above 22℃, summer begins. Accordingly, when the average temperature rises steadily from below 10℃ to above 10℃ and below 22℃, it starts in spring and falls steadily from above 22℃ to below 22℃ in autumn. This is also the current division of the four seasons from the perspective of weather and climate, and it is also recognized by the meteorological community as a standard for the division of the four seasons.
In recent years, meteorologists have divided four seasons according to the adjustment of large-scale weather situation and the sudden change of local weather and temperature, which is called "natural weather season". This method of dividing the four seasons is more progressive and more in line with the actual situation than simply using "waiting temperature" as the standard for dividing the four seasons.
According to the above four-season division standard and the statistical analysis of temperature data in Nanjing in recent hundred years, the date when Nanjing stably passed 10℃ was March 24th, the date when Nanjing stably passed 22℃ was May 26th, and the temperature dropped from above 22℃ to below 10℃ was September 19. Thus, the four seasons in Nanjing can be divided into: March 24 to May 25 in spring, a total of 63 days; May 26th to September in summer 18, a total of 1 16 days; Autumn September19-165438+1October 20th, a total of 63 days; Winter165438+1October 21-March 23, a total of 123 days. According to the above classification, Nanjing has the longest winter and summer, and the spring and autumn are only half as long as winter.
However, the start and end dates of the above four seasons are the average dates in Nanjing history for many years, not the start and end dates of the four seasons every year. As for the dates of the four seasons each year, they should be defined according to the average temperature of that year.
Second, the four seasons regimen: 1, spring regimen:
In spring, the yang is healthy, and the resistance is weak, most afraid of wind and evil. However, there is wind this season. Therefore, we should avoid the wind and evil spirits, pay attention to keep warm, don't suddenly reduce clothes, prevent colds and avoid various diseases that occur frequently in spring, such as spring temperature, wind temperature, colds and flu. Folk proverbs often say that "spring cover" means this. Pay attention to eating less sour food in diet, which can prevent excessive liver-qi, and appropriately increase sweet (sweet) food, which is beneficial to tonify temper and avoid spleen injury due to excessive liver-qi. The physical properties of the food you eat should be cold, so use or fast hot food with caution to reduce the occurrence of febrile diseases caused by excessive internal heat. Such as influenza, cold, mumps, rubella and so on. Drink chrysanthemum tea and honeysuckle on weekdays to clear away heat and dispel wind. Tea should be scented tea, cool but not cold, more neutral. Eat barley porridge, day lily, spinach, mustard, bean sprouts, duck and so on. Don't eat the internal organs of animals.
Everything revives in spring, and green food is good for health.
There is an old saying that you should avoid the cold and keep warm, and you should take precautions against the flu.
Food and clothing are often dried, and the liver likes sour taste and the spleen likes sweet taste.
Too much anger hurts the body, and peace of mind is the safest.
2, summer health care:
In summer, everything is luxuriant and beautiful, and the sunshine is strong, which is the season to breed and nurture everything. It belongs to fire in the "five elements" and is closely related to the heart and small intestine of human body. The human body, like other things, should adapt to the climate characteristics in summer. Only in this way can the healthy qi of the human body flourish and be conducive to the growth and health of the body. At the same time, it can also reduce frequent diseases in summer and prevent diseases such as summer injury, heatstroke, summer temperature, dysentery and summer cold. Sleep at night, get up early, and don't hate eternity. At noon, you can appropriately increase your nap to cushion your body. When sleeping, don't put Leng Shi and iron on your head to cool down. If you are not careful, your eyes will be damaged. Don't expose yourself outside the bedroom, lest you get tinea or face wind. Don't lie straight under the window at night, open the window to absorb wind or the air conditioning temperature is too low, which hinders the entry and exit of yang in the body. Emotionally, we should be cheerful, calm and calm, and avoid being angry, so as to make the human body unobstructed. You can do more outdoor sports, such as playing ball games, swimming, running, climbing mountains, listening to birds singing in the forest and watching the tide and flowing water, so as to integrate with nature and adapt to the seasonal characteristics of summer. But be careful not to overwork and consume, so as not to be hurt by other summer evils. At the same time, avoid exposure to the hot sun to prevent heatstroke. In summer, the human heart is full of fire and the kidney water is weak. Although it feels hot, likes cold and longs for cold, it should be restrained. Pay attention to caution in diet, avoid greasy and thick taste, reduce bitter food and increase spicy food to nourish the lungs. Don't be too full. Don't binge on iced drinks or indulge in frozen fruits and vegetables.
When summer comes, everything grows and bacteria, mosquitoes and flies breed.
Fresh food is the most delicious, and grain and oil mildew hurts people.
Greed for cold makes the body cold. Don't forget that Chinese medicine has a good prescription.
Fu Tianwai's treatment is effective. Ask the doctor about his health in time.
3, autumn health care:
In autumn, the west wind is rustling, and in the dry season, the natural scene is evaluated and converged because everything is mature. It is the season when the yang fades, the yin grows, and everything harvests. The five elements belong to gold and are closely related to the lung and large intestine of human body. The human body, like everything else, should conform to the climate characteristics of autumn, and all kinds of life activities should be restrained and not indulged. Only in this way can the spirit be restrained and not dissipated too much, thus reducing the occurrence of autumn diseases. Go to bed early and get up early in daily life, which is similar to the activity time of chickens. In the morning, you can do some peaceful exercises in fresh and sheltered places, such as playing Tai Ji Chuan, practicing Tai Ji Chuan and doing aerobics. Those who like running should also reduce their activities like early spring, and swimming should also be reduced appropriately. Can't make the body sweat and aggravate the dryness of the body. Maintain emotional stability and restraint, and don't let your thoughts wander. Only in this way can we adapt to the climate characteristics in autumn, keep the lung qi unblocked and maintain normal physiological functions. If this natural law is violated, the lungs will be injured, and indigestion and diarrhea may occur in winter.
When autumn comes, everything must be harvested, and the fruit must be paid first.
Dry gold makes the wind dry, burning straw makes the lungs uneasy.
For cough, chronic bronchitis and old lung disease, fresh air is the most important.
A year's hard work pays off, and you don't have to worry about getting sick in winter.
4, winter health care:
Winter is cold, water ice, the earth is cracked, the north wind is cold, vitality lurks, and the sun hides, which is the season when everything hides. It belongs to water in the "five elements", and this season is closely related to the kidney and bladder of the human body. The human body, like everything else, should adapt to the climate characteristics in winter, and all kinds of life activities should be hidden. You can do less outdoor activities, so that the healthy qi of the human body can be supplemented and stored, and the essence and energy can be supplemented for the freshmen in the coming year. In daily life, you should go to bed early and get up late. It is best to wait until the sun comes out to get up, ensure adequate sleep, and try to keep warm to avoid cold, so as to maintain the yang of the human body. Throughout the year, winter is equivalent to one night, so you should have more rest. In the morning, you can do some relaxing exercises in sunny, fresh and sheltered places. Never do strenuous exercise, which will make your skin sweat and consume your body's yang. Also avoid frostbite and frostbite. Try not to swim in winter to reduce nightlife.
When winter comes, hide everything, get enough sleep and bask in the sun.
Often open the window to ventilate, playing games all night is easy to get hurt.
Drink moderately and eat meat, eat less sauerkraut and eat more vegetables.
Civilized cities pay attention to hygiene and conform to the right time, place and people.