Northern autumnal equinox custom

The autumnal equinox is the sixteenth solar term in the twenty-four solar terms of the lunar calendar, usually on September 22nd or 23rd every year. The climate in the south began to decline from this solar term. The autumnal equinox of 20 12 comes early, which is the highest in recent years. According to the calculation of Purple Mountain Observatory, the exact time to enter the autumnal equinox this year is 22: 49 on September 22nd, which is also the earliest autumnal equinox in recent 1 16 years. The autumnal equinox earlier than this year can be traced back to1September 22, 896 2 1: 03.

"Equinox" has two meanings:

First, the time between day and night is equal, with long days and short nights, and short days and long nights. On this day, the sun reaches the longitude 180 degrees, and points directly at the equator of the earth, so the 24 hours of this day are divided equally, each being 12 hours. China's ancient book "Spring and Autumn Stories, Yin and Yang in and out" said: "The autumn equinox, Yin and Yang are also half-phase, so it is cold and hot day and night." At the autumnal equinox, "fen" means "half". At the autumnal equinox, the world is as long as day and night. After the autumnal equinox, the days are getting shorter and shorter in the northern hemisphere, and the nights are getting longer and longer in the southern hemisphere. At the autumnal equinox, there are no extreme days and nights in the world. After the autumnal equinox, the polar night range near the North Pole and the polar sun range near the South Pole gradually expanded.

Second, the climate changed from hot to cold. According to the division of seasons in ancient China, which started with beginning of spring, Changxia, beginning of autumn and beginning of winter, the autumnal equinox is divided into 90 days in autumn and divided equally in autumn. For example, Heshui Zuo's poem says, "Summer retreats and autumn turns sunny and cool, and the sun and the moon are the same length." After that, the position of direct sunlight moved south, and the days in the northern hemisphere were short and the nights were long. It means "it gets cold in autumn".

The meaning of the autumnal equinox: Twenty-four solar terms, China ancient book: "See the autumnal equinox in mid-August". "Divide" means to divide day and night equally. Like the vernal equinox, the sun shines directly at the equator of the earth, and day and night are equal. Since then, the position of direct sunlight has moved south, and the days in the northern hemisphere have gradually shortened, the nights have become longer, and the temperature has dropped, which is of universal significance throughout the country. In ancient China, the autumnal equinox was divided into three periods: "When thunder comes, the sound will stop;" Second, wait for scorpion blank households; Wait for the water to dry. "Wait a minute is the thunder, because the sun be the spirit is strong, after the autumnal equinox, Yin qi began to fill, no longer thunder. The word "blank" in the second phase means fine soil, that is to say, due to the cold weather, secluded small insects began to hide in Tibetan caves and sealed the hole with fine soil to prevent cold air from invading. " When the water is dry, it means that the rainfall begins to decrease at this time. Due to the dry weather, water vapor evaporates rapidly, the water volume of lakes and rivers decreases, and some swamps and puddles are drying up.

In the autumn equinox, most parts of China have entered a cool autumn. The cold air from the south meets the gradually decaying warm and humid air, which causes repeated precipitation and the temperature drops again and again. As people often say, it's time for "an autumn rain and a cold", but the daily precipitation after the autumnal equinox will not be great. At this time, the field farming in the south and the north is different. In northern China, there is an agricultural proverb that says: "The white dew is early, the cold dew is late, and it is the right time to plant wheat in the autumn equinox." Proverbs clearly stipulate the sowing time of winter wheat in this area; And "White clouds come in autumn equinox, good songs and good rice seeds are everywhere" reflects the sowing time of late rice in South China. In addition, the taboos of working people on the solar terms of the autumnal equinox are also summed up as proverbs, such as "the autumnal equinox is only afraid of lightning, and more meters are more expensive."

During this period, many parts of the country began to enter a period of less precipitation. After the autumnal equinox, the number of rainy days and rainfall in most parts of China, including Jiangnan and South China (except the rainstorm caused by tropical cyclones) entered a period of decreasing precipitation, and the water levels of rivers and lakes began to decline, and some seasonal rivers and lakes even dried up gradually. During this period, there may be individual tropical cyclones, but the impact location is south, mostly affecting the coastal areas of South China and Hainan Island. At this time, typhoons not only bring strong winds, but also bring rainfall, which is often beneficial to local soil moisture conservation, because these areas have turned into dry season after 10.