How does the weather change during the extreme day and night?
Polar day and night are unique natural phenomena within the polar circle. These special natural phenomena are the result of the earth's rotation along its tilted axis. That is to say, when the earth rotates, the earth's axis forms an inclination angle of about 23.5 degrees with the vertical. Therefore, during the earth's orbit around the sun, one of the south pole and the north pole always faces the sun for 6 months. The other pole always faces away from the sun; if the south pole faces the sun, the sunlight is strong, so the south pole will be full of daytime and no night for half a year; at this time, the north pole will not see the sun, and the north pole will be full of light for half a year. It's night, no day. In the next half year, it is just the opposite. The North Pole faces the sun, and it is all daytime at the North Pole; while the South Pole cannot see the sun at this time, and it is all night at the South Pole. In areas within the polar circle, the lengths of polar day and night vary depending on the latitude.
Polar day: In the Antarctic region, the phenomenon that the sun never sinks below the horizon within 24 hours of local time is called polar day. At the South Pole, half of the year is polar day; if refraction is taken into account, it should be slightly more than half a year. The polar day at the South Pole occurs in the second half of the Southern Hemisphere.
Polar night: Contrary to polar day, in the Antarctic region, the phenomenon that the sun is always below the horizon within 24 hours of local time is called polar night. At the South Pole, there should be polar night for half a year; if refraction is taken into account, it should be slightly less than half a year. The time when polar night occurs at the South Pole is exactly opposite to polar day, during the winter in the Southern Hemisphere.
In the Antarctic region, as the latitude decreases, the duration of polar day and polar night becomes shorter. In the polar circle, polar day and polar night only occur for one day.
If the direct sunlight point is in any hemisphere, the polar day phenomenon will occur near the poles of that hemisphere.
The range of the polar day is related to the latitude of the direct sun point, and the latitude difference between its boundary and the pole is the latitude of the direct sun point.
So, after the spring equinox, the polar day will appear near the North Pole, and then the range of the polar day will become larger and larger; it will reach its maximum on the summer solstice, and the boundary will reach the Arctic Circle; after the summer solstice, the range of the polar day near the North Pole will gradually shrink, to The autumnal equinox shrinks to 0; after the autumnal equinox, polar day appears near the Antarctic, and then the range of the polar day near the Antarctic becomes larger and larger; it reaches its maximum on the winter solstice, and the boundary reaches the Antarctic Circle; after the winter solstice, the range of the polar day near the Antarctic gradually shrinks, and on the vernal equinox shrink to 0.
This cycle starts over and over again, and its cycle is a tropical year.
As we all know, "polar day" and "polar night" occur alternately at the North and South Poles every year. There are roughly six consecutive months of daylight (called polar day) in a year, and six months of darkness (called polar night). During "extreme daylight", it is always daytime 24 hours a day. If it is sunny, the sun is shining even at midnight, as bright as broad daylight. When the "polar night" comes, the sun never rises from the horizon, and the stars keep twinkling in the black sky.
Polar day will only appear in the Antarctic Circle and the Arctic Circle. When polar day occurs in the Antarctic, polar night will appear in the North Pole, and vice versa. Because the rotation of the earth is tilted, in summer and winter, when the earth rotates, the North Pole faces the sun. No matter how the earth rotates, it always faces the sun, so there is polar day, and vice versa. The Antarctic Circle and the Arctic Circle are opposite, so when there is extreme daylight in the North Pole, there will be extreme daylight in the Antarctic, and vice versa. Polar day and polar night only appear in summer and winter.
Polar day in the Arctic Circle and polar night in the Antarctic Circle appear in summer
Polar night in the Arctic Circle and polar day in the Antarctic Circle appear in winter.
Polar night, also known as eternal night, is a phenomenon in the polar regions of the earth where the sun is below the horizon within a day, that is, the night is longer than 24 hours. Both the North Pole and the Antarctic are divided into polar day and polar night. There are roughly six consecutive months of polar day and six months of polar night in a year. During the polar night period of a month, the moon (full or missing) is visible for 15 days, and the moon is not visible for the other 15 days. The scenery of "Arctic Day" is very magical. It is always daytime 24 hours a day. If it is sunny, the sun is shining even at midnight, as bright as broad daylight. During the "Arctic Day" days, the street lights on the streets are not lit all night, and the lights in front of the cars have temporarily lost their function. Dark curtains hang low on the windows of every house, which people use to block the light. However, when "Arctic Night" arrives, it's a different scene. During the long night, except for a little light at noon, the lights must be turned on during the day! Because in the "Arctic Night", the sun never rises above the horizon, and the stars always twinkle in the dark sky. For half a month of the year, you can see the full or missing moon rotating around the sky all day long. For the other half of the month, not even the moon can be seen. This peculiar scene lasts for half a year in the central Arctic zone from mid-September to mid-March of the following year.
If the sun shines directly in one hemisphere, the polar night phenomenon will occur near the pole of the other hemisphere.
The range of the polar day is related to the latitude of the direct sun point, and the latitude difference between its boundary and the pole is the latitude of the direct sun point.
So: after the vernal equinox, the polar night will appear near the Antarctic, and then the scope of the polar night will become larger and larger; it will reach its maximum on the summer solstice, and the boundary will reach the Antarctic Circle; after the summer solstice, the scope of the polar night near the Antarctic will gradually expand It shrinks to 0 by the autumnal equinox; after the autumnal equinox, polar night appears near the North Pole, and then the range of polar night near the North Pole becomes larger and larger; it reaches its maximum on the winter solstice, and the boundary reaches the Arctic Circle; after the winter solstice, the range of polar night near the North Pole It gradually shrinks and shrinks to 0 on the vernal equinox.
This cycle starts over and over again, and its cycle is a tropical year.
Due to the existence of polar day and polar night, during the long day, animals must accumulate enough energy to eat continuously and raise their offspring efficiently, so that when the eternal night comes, except for Except for some animals that migrate to the south, those that stay can survive the most difficult period.
The living environment in the Arctic is very monotonous. It is covered with snow all year round and there are no obvious seasonal changes. People cannot see the processes of plant germination, growth, flowering and fruiting. The phenomenon of extreme daylight for half of the year and extreme night for half of the year disrupts people's biological clocks. During the extreme daylight, it is difficult for people to sleep during the day, so the Arctic indigenous people have the characteristic of sleeping less. During the long nights in winter, people's activities are mainly indoors. People who are often shut in the house will suffer from "indoor fever". After all, modern civilization has provided residents in the Arctic with a comfortable and warm life - at minus 30 degrees outside the window, people can swim in indoor heated swimming pools, play basketball and volleyball in the gymnasium, and children can play electronic game consoles; the development of satellite communication technology , also allows residents of the Arctic region to watch their favorite festivals safely every night; helicopters are busy transporting various supplies and taking you to where you want to go. Just as the Chinese turned the Great Northern Wilderness into Beidacang, humans are currently working to turn the barren Arctic into an energy base. Of course, life here is still very difficult now, and humans will still have to work hard to solve many problems in the years to come.
From March 21st to September 23rd, polar day occurs at the North Pole and polar night occurs at the South Pole
From September 23rd to March 21st of the following year, polar night appears at the South Pole Polar day and polar night appear at the North Pole
On June 22, polar day appears at the Arctic Circle and polar night appears at the Antarctic Circle
On December 22, polar day appears at the Antarctic Circle and the North Pole Polar night appears on the circle
Between the polar circle and the pole, the closer to the pole, the closer the length of day and polar night is to half a year, and the closer to the polar circle, the length of day and night is closer to one day
< p>The polar day and polar night are one of the wonders of Antarctica. It gives people a richer reverie about this mysterious land.The so-called polar day means that the sun never sets and the sky is always bright. This phenomenon is also called white night; the so-called polar night means that it is the opposite of the polar day, the sun never comes out and the sky is always dark. In the high latitudes of Antarctica, there is no life rhythm of "working at sunrise and resting at sunset", and there is no 24-hour day and night cycle. The alternation of day and night changes with increasing latitude. The higher the latitude, the longer the periods of polar day and night. At 90° south latitude, that is, at the South Pole, the alternation of day and night is half a year each. In other words, the alternation of day and night there is a whole year. Half of the year is continuous daytime, and half of the year is continuous night. One day is equivalent to one year on other continents. If you leave the South Pole, the lower the latitude, there will no longer be half a year of day or half a year of night, and the length of polar day and polar night will gradually shorten. At 80° south latitude, there are also times other than polar day and polar night where the 24-hour day and night cycle occurs. If it is at the end of the polar day, the night time will be very short at first, and then the night time will become longer and longer, until finally it is all dark, and the polar night will begin. In the Antarctic Circle (66°33’ South Latitude), there is only one full day (24 hours) of full day and one full day of night in a year. The China Antarctic Great Wall Station (62°13’ south latitude) is located outside the Antarctic Circle. At one or two o’clock in the middle of the night in December, the sky is still bright and you can read and write with good eyesight. This natural phenomenon of polar day and polar night also occurs at the other pole of the earth, the North Pole, but the time it appears is exactly opposite to that of the South Pole. If the North Pole is in polar day, the Antarctic is polar night, and vice versa.
The formation of polar day and polar night is caused by the fact that the earth rotates around its own tilted axis while revolving around the sun in an elliptical orbit. It turns out that when the earth rotates, the earth's axis forms an inclination angle of about 23.5° with its vertical line. Therefore, when the earth rotates, for 6 months, one of the two poles always faces the sun, and it is always daytime; the other pole always faces the sun. With your back to the sun, it's all night. This magical natural phenomenon in the South and North Pole is not found on other continents.