What Is a Polar Night?

Polar night, also known as Yongye, is a phenomenon in which the sun is below the horizon within one day of the earth's polar regions, that is, the night is 24 hours long. There are polar days and polar nights in the Arctic and Antarctica. The polar days and polar nights are roughly six consecutive months in a year. During the polar night period of a stellar moon (about 27.3 days), the moon (round, missing) is visible for half a month, and the moon is not visible for the other half.

The view of "Arctic Day" is very wonderful. It every day

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There are not many kinds of creatures living in Antarctica, which have peculiar ability to adapt to the environment. Mainly in terms of resistance to darkness, low temperature, high salt, and dryness. During long polar nights, Antarctica creatures mainly survive by changing their colors, changing their metabolic patterns, and dormant. In a freshwater lake in Victoria, there is a "lakeweed" that can tolerate polar nights for 4 months. Before polar nights, it can make full use of daylight to efficiently photosynthesize and synthesize a large amount of organic matter. In addition to these organic matter for its growth and development, the remaining part is discharged outside the body and stored in the water environment where it lives. During the polar night, it stops photosynthesis and absorbs the organic matter it releases, maintaining minimal metabolism, and can develop and grow. There is a creature called rotifer, which can sleep for 4 months without eating and drinking, and spend long polar nights. There is also a kind of creature called "ice and snow algae", which changes to green when there is sunlight and blue-green when it is dark. Depending on this transformation, it absorbs light of different wavelengths for photosynthesis and survives. ^[2]

Due to the existence of polar days and polar nights, animals must accumulate enough energy to feed constantly during the long daytime, and also to efficiently raise offspring. In this way, when the night comes, except for some animals that migrate to the south What's more, those animals that survive can go through the most difficult times.

The living environment in the Arctic is very monotonous. It is snowy all year round, and there is no obvious seasonal change. People do not see the process of plant germination, growth, flowering, and fruiting. The phenomenon of extremely polar day and half polar day in the middle of a year disturbs people's physiological clock. During polar days, it is difficult for people to sleep during the day, so the indigenous people of the Arctic have less sleep; long winter nights, people's activities are mainly indoors, and people who are often kept indoors will suffer from "indoor fever". After all, modern civilization provides a comfortable and warm life for the residents of the Arctic region-minus 30 degrees outside the window, people can swim in the indoor heated pool, play basketball and volleyball in the gym, children can play video games; the development of satellite communication technology It also makes residents of the Arctic region watch their favorite programs safely every night; helicopters are busy transporting various supplies and taking you where you want to go. Just as the Chinese turned Beidahuang into Beicang, mankind is working to turn the barren Arctic into an energy base. Of course, life here is still very difficult, and human beings will have to work hard to solve many problems in the years to come. ^[3]

Polar nights motivate people to travel, and Sweden and Norway are extremely affected by the sun. In the middle of the winter, the territories within the Arctic Circle are polar nights, while the parts outside the Arctic Circle can only enjoy six or seven hours of sunshine a day. In Sweden, when the extreme night is approaching, nature-loving people choose to travel through the long winter.