Why does the North Pole have a polar day How many days does the North Pole have in a year?

If the direct point of the sun is in which hemisphere, the polar circle to the pole area of that hemisphere will occur the polar daylight phenomenon.

The range of the polar day is related to the latitude of the direct solar point, and the latitude difference between its boundary and the pole is the latitude of the direct solar point.

Therefore, after the vernal equinox, there will be a polar day near the North Pole, and the polar day will become larger and larger thereafter; Reaching maximum on the summer solstice, the boundary reaches the Arctic Circle; After the summer solstice, the range of polar days near the North Pole gradually decreases, and it shrinks to 0 on the day of the autumnal equinox. After the autumnal equinox, the polar day appears near the South Pole, and the range of the polar day near the South Pole becomes larger and larger thereafter. Reaching its maximum on the winter solstice, the boundary reaches the Antarctic Circle; After the winter solstice, the range of polar days near the South Pole gradually decreases, reaching 0 on the vernal equinox.

And so on and so forth, and the cycle is a return year.

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Problem description: I want to know how many days there is no sun at the North Pole? How many days does the sun not set? It's best to tell me how many days it is from that day to the end of the day. Please, great immortals!! 100,000 urgent.

Analysis: Less than half a year.

On the spring and autumn equinoxes, day and night are equally divided around the world. The morning and dusk lines (circles) coincide with the meridians.

From the vernal equinox (March 21) to the summer solstice (June 22), the direct point of the sun moves north to the Tropic of Cancer (23 degrees 26 minutes north latitude), the morning and dusk line (circle) is deflected, and the North Pole begins to appear polar day, and on the summer solstice, the Arctic Circle (66 degrees 34 minutes north latitude) is full of polar day.

From the summer solstice to the autumnal equinox (September 23), the direct point of the sun moves south back to the equator, and the angle between the morning and dusk lines (circles) and the meridians decreases, coinciding with the autumnal equinox.

From the autumnal equinox to the winter solstice (December 22), the direct point of the sun continues to move south towards the Tropic of Cancer (23 degrees 26 minutes south latitude), when the polar night appears at the North Pole, and on the winter solstice, the polar night appears in the Arctic Circle.

However, due to the fact that the Earth's orbit is elliptical, the beginning of January is the fastest rotation speed of today's point, and the beginning of July is the slowest rotation speed of the aphelion point, so the summer half year (spring equinox - summer solstice - autumn equinox) is shorter than the winter half year (autumn equinox - winter solstice - spring equinox), that is to say, the polar day time of the North Pole is less than half a year.

Polar day only occurs in the Antarctic Circle and the Arctic Circle, and when there is a polar day at the South Pole, there is a polar night at 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 is towards the sun, and no matter how the earth turns, it is always towards the sun, so there is a polar day, and vice versa. The Antarctic Circle and the Arctic Circle are opposites, so when there is a polar day in the North Pole, there is a polar day in the South Pole, and vice versa.

Polar day and polar night only occur in summer and winter.

Principle The so-called polar day means that the sun never sets and the sky is always bright, which is also called white night; The so-called polar night 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 "sunrise and sunset" rhythm of life, and there is no 24-hour day and night cycle. The alternation of day and night changes with increasing latitude, and the higher the latitude, the longer the polar day and the polar night.

At 90° south latitude, that is, at the South Pole, the alternation of day and night alternates for half a year, that is, the alternation of day and night there is a full year, half of the year is continuous day, half of the year is continuous night, and one day there is equivalent to a year on other continents. If you leave the South Pole, the lower the latitude, the more day or night it is, and the time of the polar day and night will gradually shorten. At 80°S, there are times when the polar day and night are other than the polar day and night, and there is a day-night cycle of 1 day and 24 hours.

If you are at the end of the polar day, the night is very short at first, and then the night is getting longer and longer, until finally it is all night, and the polar night begins. In the Antarctic Circle (66°33'S), there is only one full day (24 hours) of the year that is all day and one full day is all night. China's Antarctic Great Wall Station (62°13'S) is just outside the Antarctic Circle, and at one or two o'clock in the middle of the night in December, the sky is still cloudy and you can read and write with good eyesight.

This natural phenomenon of polar day and polar night also occurs at the North Pole, the other pole of the earth, but it occurs at the opposite time of the South Pole, and if the North Pole is in the polar day, the South Pole will be the polar night, and vice versa. The formation of the polar day and the polar night is caused by the rotation of the earth around its own inclined axis as it orbits the sun in an elliptical orbit. It turns out that when the earth rotates, the earth's axis and its perpendicular line form an approximate inclination angle, so when the earth rotates, there is always one of the poles facing the sun for 6 months, and it is all daytime; The other pole is turned away from the sun, and it is all night.

The North and South Poles are amazing natural phenomena that no other continent has.

Everyone knows that a day and night are equal to a day, that is, 24 hours. Why is a day and a night in the Arctic a year?

As the Earth rotates, it also revolves around the Sun. The Earth's rotation from west to east around the Earth's axis is called rotation, and the Earth's rotation is one day and night, with 24 hours. The movement of the earth around the sun is called revolution, the earth.

One revolution is one year. An important feature of the Earth's revolution is that the orbital plane of the Earth's revolution is always at an angle to the Earth's axis, and the North Pole always points near the North Star. Because of this.

An important feature is that in the process of the Earth's revolution around the Sun, the Sun sometimes shines directly in the Northern Hemisphere, sometimes in the Southern Hemisphere, and sometimes directly on the equator. Throughout the year, the direct point of the sun is always.

Moves back and forth between northern and southern latitudes.

Every year around March 21, the direct point of the sun is at the equator, and the North Pole sun does not set throughout the day. It is spent 24 hours a day during the day. This is the polar day.

Later, as the direct point of the sun moved northward, the range of the Arctic polar day gradually expanded, and by the summer solstice in the Northern Hemisphere, the polar day expanded to the Arctic Circle. After that, the direct point of the sun no longer moved north, but began to move south, and the polar day range of the North Pole began to gradually shrink, and the daylight time of the North Pole was not finished until around September 23, when the sun passed the equator directly. During this time, the closer you get to the North Pole, the more days the polar day lasts, reaching 191 days.

During this period, there is no night in the Arctic, it is all day, that is, half the day.

After the autumnal equinox in the Northern Hemisphere, the sun shines directly in the southern hemisphere, and the sun does not rise in the North Pole. Spend 24 hours a day in the dark, and this is the polar night. Until the northern hemisphere equinox the following year, the Arctic is spent in long nights.

The closer you get to the North Pole, the more days the polar night lasts. The number of polar night days that lasted in the Arctic was 174. During this period, the Arctic was dark for half a year.

The situation at the South Pole is the opposite of the North Pole, except that the number of days and nights is different from the North Pole. Therefore, when we say that the north and south poles are a big day and night, half a year of day and half a year of night.