Bai Lulu Qiu is different at night, why is it "cold one night and one night"?｜ Folk Calendar · Twenty -four solar terms

Bai Lu: The solar term with the largest temperature difference between day and night in the year

Bai Lu is the 15th festival in the "twenty-four solar terms", the third festival in autumn, generally starting on September 7-9 of the Gregorian calendar. "Bai Lu" is an important solar term that reflects the growth of cold in nature. As the weather gradually turned cold, the sun was hot during the day, but the temperature fell quickly after the evening, and the temperature difference between day and night was large. Bai Lu is the most temperature difference between day and night in the year. Although the temperature still reached 30 degrees during the day, after night, it fell to twenty degrees, and the temperature difference between the two reached more than ten degrees. The larger the worship of the north to the north, the larger the north, and the northwest and northeast can even reach 18-20 ° C.

From the perspective of precipitation, at this time, the precipitation in northern China has decreased significantly, the autumn is high, and it is relatively dry. During this period in the middle and lower reaches of the Yangtze River, the first autumn rain can often alleviate the water shortage caused by hot early stage, but if the cold air encounters a typhoon or the warm and cold air is evenly matched, it will make people depressed and it will be more depressed. The formation of heavy rain or low -temperature rainy weather is particularly unfavorable to the growth of autumn crops.

Wang Li, a lecturer of the Department of Atmospheric Sciences of Shenyang Agricultural University of Agricultural University, conducted science science courses for elementary school students. Interviewee confidence

Bai Lu Qiu Qiu is split at night, cool overnight and one night

After entering Bai Lu, the temperature dropped rapidly, so people love to use the "white dew autumn wind night, overnight and one night" farm proverb to describe the speed of the temperature decline.

Why does this situation appear? Wang Liwei introduced that when Bai Lu, the warm summer wind gradually became replaced by winter wind, and the cold air turned into an attack. In addition, the direct sunlight point moved south, the sunshine time of the northern hemisphere became shorter, the light intensity weakened, and the ground radiation of the ground was fast. The decrease is also gradually accelerating. Dewest is the water droplets that are condensed on the ground or near -ground objects due to decreased temperature. The dew brought by Bailu's solar terms is actually depicting the cold of the weather, especially at night weather has begun to get cold. At this time, people will clearly feel that the hot summer is over, and the cool autumn has arrived.

Bai Lu has three years: Hongyanlai, Xuan Bird returned, and the birds are shy

Bai Lu has three waiting: one waiting for Hongyan, the two waiting birds return, the three waiting birds are ashamed. The overall meaning is that it is cold. The migratory birds have to go to the south to spend the winter, and other birds have to start preparing winter food in winter. Bai Lu is also the only three waiting characteristics in the twenty -four solar terms. As a keen "climate forecast", birds reflect the climate and temperature changes when Xiaqiu alternate.

Wang Liwei introduced, specifically, in the case of time, the cold geese, who are more afraid of cold, start to migrate south every September; when the second time, the swallows will fly to the south to the winter, because the swallows are all kinds of pests. In order to eat, in the winter, most insects were hidden, and some were frozen to death. Swallows have no food to eat, so they have to fly to the south to spend the winter; in the third time, because many birds do not need to go to the south to spend winter, like sparrows, magpies, etc., but there are not many foods that can be eaten in winter. These birds can be eaten. At this time, the food will be stored in the winter, and shame is to prepare for the winter, such as the meaning of Zangzhen.

Bailu Ferry Ferry Agricultural Business is busy with rice harvesting in Sichuan region.

Bai Lu's solar terms represent the heat to cool, and everything grows with the cold, and many crops have gradually matured. The season of Bailu is the busy season from all over China. In the northern region, you have started harvesting valley, sorghum and soybeans, and cotton is began to pick cotton. At the same time, you need to give the next cotton, corn, sorghum, valley, soybean, etc., and timely land and fertilizer. North China must also grab wheat in time. At this time, it is easy to rain at this time, and most of the rainfall has the characteristics of small intensity, rainy days, and continuous continuous continuous. In this regard, we must take corresponding agricultural technical measures to reduce or avoid the dangers of autumn rain.

In the season of Bailu, the agriculture is quite busy, and some crops such as rice have to hurry up to harvest. The late autumn crops such as corn and sweet potatoes can strengthen field management, promote precocious precocious, and avoid harm of low temperature frost in a period of time. And it is especially important to pay attention to the influence of West China Autumn Rain. The main feature of West China Autumn Rain is that there are more rain days, and it is mainly drizzle. The drizzle blocked the sun, bringing low temperature, which is not conducive to the harvest of corn, sweet potato, late rice, cotton and other crops and wheat sowing and rapeseed. The years of autumn rain can also make mature crops germinate and mildew, resulting in reduction or even loss. And it not only affects the harvest of crops, but also affects the production of crops in the coming year.

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