The winter solstice is the shortest day and longest night in the Northern Hemisphere, and the further north you go, the shorter the day, which is why the polar night phenomenon appears in the North Pole. On the winter solstice, the sun shines directly on the Tropic of Capricorn, and the sunlight is most inclined to the northern hemisphere, and the solar altitude angle is the smallest.
The winter solstice is the turning point of the sun's direct return to the south. After this day, the direct point of the sun will move north from the Tropic of Capricorn, and the daylight in the Northern Hemisphere will increase day by day. The length of day and night varies in different parts of the Earth depending on the tilt of the Earth's axis. In the north and south poles of the earth, the sun shines obliquely throughout the year, and the length of day and night varies the most.
The phenomenon that the sun does not set or does not come out all day in the high latitudes of the northern and southern hemispheres, that is, the day is day or night 24 hours a day, is the phenomenon of "polar day" and "polar night" in the polar region. At the North and South Poles, there are half a year of polar day and polar night.
The arrival of the winter solstice solar term marks the beginning of a cold winter. On this day, the Northern Hemisphere received the least solar radiation, about 50% less than the Southern HemisphereHowever, this is not the coldest time, the so-called "cold in."
Three. Nine, forty-nine". This is because there is an atmosphere and moisture on the earth's surface, which can store heat, and it is not "stored and lost", but "accumulated heat".
As a result, the weather is usually not very cold before the winter solstice. After the winter solstice, although the altitude angle of the sun gradually rises, it is a slow recovery process, and the heat lost every day is still greater than the heat received, showing a situation of "making ends meet".
To the "three. Nine, forty-nine days", the least accumulated heat, the lowest temperature, the weather is getting colder and colder. At this time, if there is the influence of cold air, the weather is even colder. After this "cold front", the weather will gradually warm.
From the perspective of solar terms, the beginning of spring is the beginning of the rise of yang energy in the "yin and yang" qi, since the beginning of the spring yin and yang transformation, yang energy rises, the beginning of spring marks the opening of a new cycle and the rebirth of all things;The winter solstice is the starting point of the sun's return, since the winter solstice, the height of the sun rises, the winter solstice marks the direct movement of sunlight into a new cycle, the day is increasing day by day, the ancients also regarded the winter solstice as a "auspicious day".
Today's winter solstice, I wish you all a happy holiday and remember to eat dumplings.
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