When is the polar day and night in the Arctic Circle?

Every year in the Arctic Circle, around March 21 of the Gregorian calendar, that is, at the time of the vernal equinox, the sun shines directly on the equator. From this day onwards, the polar day begins to appear within the Arctic Circle. At first, it is only around the north, and on the summer solstice, the sun shines directly on the Tropic of Capricorn, when the polar day range of the Northern Hemisphere reaches its maximum, which is all north of the Arctic Circle.

After that, the polar day range slowly decreased, and by the autumnal equinox around September 23, only the points on the Arctic Circle had polar day. After this day, the polar night begins, also at the point on the Arctic Circle, and then extends to the entire Arctic Circle. Around the winter solstice on December 22, the sun shines directly on the Tropic of Capricorn, and the entire area north of the Arctic Circle is polar night.

Then the polar night range gradually retracted, and around March 21 of the following year, that is, at the vernal equinox, the polar night ended, and the polar day began again.

Polar Day of the North Pole: March 21 - September 23 every year; Arctic Polar Night: September 23 – March 21 of the following year.

The Northern Hemisphere equinox begins around the Arctic Circle.

The inner sun never sets throughout the day, and the day is spent 24 hours a day. The Northern Hemisphere begins around the autumnal equinox, but inside the Arctic Circle, it's a different story. The sun doesn't come out all day, and it's a long night 24 hours a day. Moderate.

Arctic Circle: Polar Day: June 22; Polar Night: December 22.

The polar day of the Arctic Circle is the day and the polar night day.

The polar day of the Arctic Circle coincides with the day of the summer solstice, and the polar night coincides with the day of the winter solstice.

The rest of the time it is not.

The polar day of the Arctic Circle is around the summer solstice, and the polar night is around the winter solstice.

Half a year of summer in the Northern Hemisphere, polar day in the Arctic Circle;

Half a year of winter in the Northern Hemisphere, polar night in the Arctic Circle.

The Arctic Circle has both polar day and polar night, which changes at the Tropic of Cancer depending on where the sun shines.

The polar night is due to the fact that the direct sun point moves towards the Tropic of Capricorn at the equator after the autumnal equinox, and the polar night near the North Pole appears, and the polar night near the North Pole becomes larger and larger thereafter. Reaching its maximum on the winter solstice, the boundary reaches the Arctic Circle; After the winter solstice, the polar night near the North Pole gradually decreases to 0 on the vernal equinox, and the polar day is formed when the direct sun point moves to the Tropic of Capricorn.

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.

When the earth rotates, the earth's axis forms an approximate inclination angle with its perpendicular line, so that 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.

Polar night, the three months before and after the summer solstice is the summer in the Northern Hemisphere, and in the summer, the longer the daylight hours are the further north you go, and the polar day phenomenon occurs in the Arctic region.

Every year in the north and south poles, "polar day" and "polar night" alternate. Six consecutive months in a year are daylight (called polar day) and six months are night (called polar night). The alternation of day and night changes with increasing latitude, and the higher the latitude, the longer the polar day and the polar night.

Due to the existence of the angle between yellow and red, when the sun hits the Tropic of Cancer directly, it is the summer solstice of the northern hemisphere and the winter solstice of the southern hemisphere. Therefore, in geography, the winter solstice must be preceded by the hemisphere. Under normal circumstances, we all call the winter solstice in the northern hemisphere the winter solstice.

If you are talking about the winter solstice on December 22 (winter solstice in the Northern Hemisphere, summer solstice in the Southern Hemisphere), then the polar night phenomenon exists throughout the Arctic Circle.

It depends on which line of latitude it is. Depending on the latitude value, the duration of the polar day and the polar night is also different.

Due to the inclination of the Earth's axis, the Earth is located at different positions in its orbit and the angle of direct sunlight is also different. On the equinox, the sun shines directly on the equator, and there is no polar day and night at the north and south poles. From the second day of the vernal equinox, the direct point of the sun moves north, and the polar day phenomenon begins at the North Pole and the polar night phenomenon begins at the South Pole.

As the direct sunlight continues to move northward, the range of polar day in the Arctic region is increasing, and the range of polar night in the Antarctic source search area is also increasing. By the summer solstice, the direct point of the sun is at the Tropic of Capricorn, and the Arctic region has the largest range of polar daylight, reaching the latitude line of the Arctic Circle. The extent of the occurrence of polar nights in the Antarctic region is also maximum, reaching the latitude line of the Antarctic Circle.

After that, the direct point of the sun shifted southward, and the extent of the polar day in the Arctic began to shrink, and the extent of the polar night in the Antarctic region also began to decrease. On the day of the autumnal equinox, the sun shines directly at the equator again, and the polar day and night phenomena at the poles disappear.

Therefore, if it is on the north and south poles, the time of the polar day and night is half a year. If it is a fissimile in the Arctic and Antarctic Circles, the time of the polar day and the night is one day each.

a.Spring. b.Summer solstice.

c.Autumnal equinox. d.Winter Solstice (Correct Answer).

Answer analysis: The earth's rotation direction is from west to east, hail when the sun's rays shine directly on the Tropic of Capricorn, this day is called the winter solstice, which is December 22, the northern hemisphere has short days and long nights, and there is a polar night phenomenon in the Arctic Circle; When the sunlight shines directly on the Tropic of Cancer, this day is called the summer solstice, which is June 22, and the days in the northern hemisphere are long and the nights are short, and there is a polar day phenomenon in the areas within the arctic type of Beijian circle.