Little heat

Little heat

Xiaoshu, the eleventh solar term of the 24 solar terms, is the end of the noon moon and the beginning of the last month of the Ganzhi calendar. Dou Zhixin, the sun reaches 105 degrees of the Yellow longitude, and it meets on July 6-8 of the Gregorian calendar every year. Heatstroke means hot. Small heatstroke means small heat, not very hot. It's getting hot, but it's not the hottest yet. Although light heat is not the hottest season in a year, it is followed by the hottest solar term, big heat. There is a folk saying that "light heat, big heat, steaming up and boiling down". Many places in China have entered the season with the most thunderstorms since the summer heat.

The so-called "heat in the dog days", dog days usually appear between the heat and summer, is the highest temperature in a year and humid, muggy period. Monsoon climate is the main feature of China's climate. In summer, affected by the warm and humid air flow from the ocean, China has high temperature, humidity and rainfall. Although this season is sunny, hot, humid and rainy, for crops, the same period of rain and heat is conducive to growth.

In ancient times, people had the custom of "eating new food" during the summer heat. That is to say, after the summer heat, people try new rice. After milling the newly cut rice into rice, they prepare a good meal for the worship of the five grain gods and ancestors. Please bless the weather. The new rice is ground into flour and made into various delicacies to share with neighbors and villagers to express their wish for a bumper harvest.

Brief introduction of solar terms

Xiaoshu is called "Xiaore", which means that although we can feel the hot weather at this time, it is not the hottest in a year. Xiaoshu is just the beginning of the hot summer. The monsoon climate is the main feature of China's climate. The monsoon climate is a mixture of continental climate and marine climate. In summer, it is affected by the warm and humid air flow from the ocean, with high temperature, humid and rainy. The high temperature of monsoon climate is basically consistent with the rainy period, and the same period of rain and heat is conducive to the growth of crops. In the light heat season, the weather is hot and thunderstorms are frequent, which is the season when all things grow wildly.

Although the little heat is not the hottest season in a year, it is followed by the hottest big heat in a year. There is a saying among the people that "the little heat and the big heat, steaming on the top and boiling on the bottom". The weather will also be more and more muggy and humid, with scorching heat all over the world, making people have no place to hide. When it comes to the summer heat, the earth will no longer have a cool wind, and there will be heat waves in the wind. In the light summer, it is midsummer in southern China, and some places also enter the season of thunderstorm, which is often accompanied by gale and rainstorm. From the beginning of the heat, people are ready to meet the heat.

Climatic characteristics

Climate refers to the annual average state of the atmosphere in a region. The main climatic factors include temperature, precipitation and light, among which precipitation is an important factor. The distribution characteristics of precipitation in an area can be divided into regional distribution and seasonal distribution. China is located in the east of the Eurasian continent and the west coast of the Pacific Ocean. There are huge differences in the thermal properties between the sea and the land, thus forming the most typical monsoon climate in the world. Monsoon climate is the main feature of China's climate. In summer, it is affected by the warm and humid air from the ocean, with high temperature, humid and rainy. The southeast monsoon brings moist air from the sea. It first landed in the south of China and collided with the Siberian cold wind on the mainland. Therefore, the south of China entered the rainy season first. The precipitation in most areas of China is mainly caused by the southeast monsoon, so the precipitation in China presents the characteristics of "decreasing from southeast coast to northwest inland".

The southeast monsoon brings water vapor to our country, and the southeast coastal area of our country will get the water vapor first, forming rich precipitation, which will become the area with the most abundant annual precipitation in our country. The southwest monsoon also brings precipitation to China, which can affect South China; when the southwest monsoon develops strongly, it can also go deep into the Yangtze River Basin. The southeast monsoon region of China is bounded by the Qinling Huaihe River. The annual precipitation in the south of Qinling Huaihe River is more than 800mm, which belongs to the rainy region; while the annual precipitation in the north of Qinling Huaihe River is less than 800mm, which belongs to the less rainy region. In late July, the subtropical monsoon belt moves from North China to Northeast China. From late July to early August, it is the rainy season in North China and Northeast China. However, Northwest China is the arid area with the least annual precipitation in China because of its deep inland and distant from the sea. According to the seasonal distribution of precipitation, the precipitation in China is mainly concentrated in summer, that is, when the southeast monsoon is prevailing, so the climate characteristics in most areas of China are "the same period of rain and heat".

In the light heat season, the sunshine time in the northern hemisphere is gradually shortened, but why is the temperature still rising in most parts of China? This is because although the point of direct sunlight moves southward, it is still directed to the northern hemisphere. The heat in the northern hemisphere is still greater than that in the northern hemisphere, so the temperature will continue to rise during this period of time. As the saying goes, "heat in the dog days", this is the beginning of the dog days. Small heat is small heat, but not very hot. Big heat is the hottest time of the year. After the light heat, parts of southern China entered the season of thunderstorms. Tropical cyclone activities are frequent, and the number of tropical cyclones landing in China is increasing. In a word, the climate characteristics of light summer solar term are hot weather and thunderstorm increasing.

Division of solar terms

"Twenty four solar terms" is the product of ancient agricultural civilization. It was originally formulated according to the change of stars. The Big Dipper is an important star in the northern hemisphere (China is located in the northern hemisphere). When the change of stars, the natural rhythm of the corresponding regions in the northern hemisphere is gradually changing. Therefore, it becomes the basis for ancient people to judge the change of energy-saving, that is, the so-called "doubing refers to the East, the world is spring; doubing guide, the world is summer; doubing guide, the world is spring; doubing guide, the world is summer; "Doubing refers to the west, the world is autumn; doubing refers to the north, the world is winter". The rotation of the Big Dipper's handle points to a certain solar term, and the sharp dipper's finger is a slight heat stroke.

In the period of Emperor Wu of the Western Han Dynasty, "24 solar terms" were included in the Taichu calendar as the calendar to guide farming. In the middle and lower reaches of the Yellow River, the day with the longest shadow and the shortest day (solstice) is used as the winter solstice day. Taking the winter solstice day as the starting point of the "24 solar terms", the winter solstice day is measured first. Because the shadow is the longest in the winter solstice, the change of shadow length in the adjacent days is the most obvious, which is more conducive to observation and recording. The winter solstice and the next winter solstice are divided into 24 equal parts, the time between each "solar term" is equal, and the interval between each solar term is 15 days, so it is also called "average time method". The solar term determined by the "average time method" is heatstroke 150 days after the winter solstice.

The current "24 solar terms" are determined according to the position of the sun on the returning ecliptic, that is, in a 360 degree circle of the "ecliptic" (the sun's apparent path on the celestial sphere in a year), it is divided into 24 equal parts, every 15 ° is one equal part, and every one equal part is a solar term. Together, it is exactly 24 solar terms. It is based on the vernal equinox as the starting point of 0 degree (the beginning of spring is still ranked first in the order), and arranged according to the degrees of the Yellow meridian. Every 15 degrees of the sun in the ecliptic is a "solar term", and the "degrees" of each "solar term" are equal. The solar term defined by the degree of the sun's yellow longitude. When the sun reaches 105 degrees of the Yellow longitude, it is a light heat stroke.

Seasonal customs

In the old days, there was a custom of "eating new food" in southern China. "Shixin" is to grind new rice and wheat into flour and make them into various kinds of flour cakes and noodles, which can be shared by neighbors and villagers to express their wish for a good harvest. At the same time, these new goods also need to prepare a sacrifice to their ancestors. "Heaven and earth are the origin of life; ancestors are the origin of category." Heaven and earth are the basis of life, and ancestors are the basis of human beings. Ancestor worship is a custom of inheriting filial piety.

It's a custom in northern China to eat dumplings in the morning. People in the morning often lose appetite and tend to be thinner than those in the morning. It's commonly known as bitter summer. In the traditional custom, dumplings are just appetizers. Some places in Shandong eat raw cucumbers and boiled eggs to cure the bitter summer. They eat eggs in the morning, and they don't eat any other food.

Solar term farming

General situation of precipitation

China has a vast territory, and the climate in summer is not the same in different regions. Generally speaking, the monsoon area in Southeast China is hot and rainy in summer, the northwest is hot and dry in summer, and the southwest is cool and rainy in summer.

There is a folk saying: "May is long in South China and June (in the middle and lower reaches of the Yangtze River), and rain is boundless in North China and Northeast China." It vividly describes the movement of rainfall belt in China.

The southern part of China is already in the rainy season. With the strengthening of the southeast monsoon, the northern part of China (North China and Northeast China) will also have rainy weather from late July to early August of the Gregorian calendar.

flood and water-logging

China's climate law is high temperature and rainy in summer, the impact of the same period of rain and heat on agriculture should be divided into two aspects, one is favorable, the other is unfavorable. Favorable: sufficient water and heat, favorable to the growth of crops, unfavorable: due to the concentration of precipitation, it is easy to cause floods and reduce agricultural production.

Summer drought

China's climate is "rainy and hot at the same time", but there will be summer drought in some places. The summer drought is generally from the middle of July to the middle of August. At this time, the Meiyu static front had moved to the middle and lower reaches of the Yellow River and Northeast China in early July, and the middle and lower reaches of the Yangtze River were controlled by the "subtropical high", forming an anticyclonic weather, with the downdraft dominated, long sunshine, strong solar radiation, high temperature and strong evaporation. The crops grow fast, and the farmland needs a lot of water. However, due to the single air mass, except for thunderstorms in some areas, there is no large rain area, and the weather is generally dry and hot, so it is called "summer drought". Summer drought mainly occurs in the Yangtze River Basin and Jiangnan region, especially in Hubei, Hunan, Jiangxi, Jiangsu, Anhui and other provinces. When the Western Pacific subtropical high is controlled and there are few typhoons, it is easy to be controlled

Chinese PinYin : Xiao Shu