On the summer solstice, the height of the Sun decreases from the Tropic of Cancer to the north and s

On the summer solstice, the sun shines directly on the Tropic of Capricorn, and on this day, the height of the sun in and north of the Tropic of Cancer reaches its maximum, and the height of the sun decreases from the Tropic of Cancer to the north and south. You can draw a triangle and look at it, the vertex a is the sun, and the vertical line downward is the perpendicular plane downward, and the vertical foot is the direct point of the sun. At this time, the solar altitude of the direct point is 90°, and the sunlight can be received from 90° to the south and north, and the angle between the line between the sun and the desired point and the ground is the solar altitude angle.

In other words, the height of the sun on both sides of the direct point is smaller than the height of the sun at the direct point, so on the summer solstice, the height of the sun at noon decreases from the Tropic of Cancer to the north and south.

The angle between the line between the sun and the point sought and the ground is the angle of the sun's height. In other words, the height of the Sun decreases from the Tropic of Cancer to the north and south everywhere. You can draw a triangle and look at it, vertex a is the sun, and make its perpendicular line down to the perpendicular plane downward.

At this time, the solar altitude of the direct point is 90°, and the sunlight can be received from 90° to the south and north, and the vertical foot is the direct solar point on the summer solstice (6, on this day, the solar altitude of the Tropic of Cancer and north of it reaches its maximum. 22) when the sun shines directly on the Tropic of Capricorn.

On the summer solstice, the sun shines directly on the Tropic of Cancer, and the noon solar altitude angle of the Tropic of Cancer is the largest, which is 90 degrees, and the noon solar altitude angle on the north and south sides of the Tropic of Cancer is naturally not as large as the Tropic of Cancer.

On the summer solstice, the direct point of the sun is on the Tropic of Capricorn, when the height of the sun decreases from the Tropic of Cancer to the north and south at noon, and the Antarctic Circle and the region south of it are polar nights.

On the summer solstice, the altitude angle of the Sun on the Tropic of Cancer is 90 degrees.

The maximum altitude angle of the sun is 90 degrees, so whether it is to the south or north, the altitude angle must be less than 90 degrees, and the farther away from the Tropic of Cancer, the smaller the altitude angle of the sun.

I think it's easy to understand that the height of the sun mentioned in the title is the angle between sunlight and the ground. On the summer solstice, the sun shines directly on the Tropic of Capricorn, and the direct sunlight is illuminated from above, so that the angle between the sunlight and the ground is 90 degrees, and the angle between the sun and the ground on the north and south sides will be less than 90 degrees, and it is decreasing.

On the summer solstice, the sun shines directly on the Tropic of Capricorn, reaching a maximum altitude of 90 degrees, after which the sun gradually increases towards the equator! The sun in the Southern Hemisphere is also getting taller!

The direct sun is on the equator on the spring and autumn equinoxes, the direct sun is on the Tropic of Cancer on the summer solstice, and the direct sun is on the Tropic of Capricorn on the winter solstice.

The rotation and rotation of the earth form a yellow-red angle, which produces the periodic changes of the direct sun's point between the Tropic of Cancer, which also forms the periodic changes in climate, the length of day and night, and the height of the sun.

Summer is the season of the year when the days are longest and the sun is at its highest. The starting point is the beginning of spring (February 4 or 5), the beginning of summer (May 5 or 6), the beginning of autumn (August 7 or 8), and the beginning of winter (November 7 or 8) among the 24 solar terms.

The Earth's orbit produces regular changes in weather and seasons, and farmers in traditional agriculture carry out agricultural production according to this, as the proverb goes: "Plant melons and beans before and after the rain".

The yellow-red angle is the direct cause of the astronomical seasons. This is because:

The distribution of solar height at noon with latitude is as follows: low latitude is large and high latitude is small, spring and autumn equinox, decreasing from the equator to the poles; On the summer solstice, it decreases from the Tropic of Cancer to the north and south; On the winter solstice, it decreases from the Tropic of Cancer to the north and south.

Seasonally, north of the Tropic of Capricorn, the height of the sun reaches its maximum at noon around the summer solstice, and reaches its minimum around the winter solstice. South of the Tropic of Capricorn is the opposite. In the area between the Tropic of Cancer and the Tropic of Capricorn, the sun shines directly twice a year.

Summary. On the summer solstice, which is summer in the Northern Hemisphere and winter in the Southern Hemisphere, the Earth's axis of rotation tilts so that parts of the Arctic Circle can see the Sun at its highest position. The Tropic of Cancer is the place where the latitude on both sides of the equator is degrees, and the direct point of the sun is located on the Tropic of Cancer.

On the day of the summer solstice, which is the summer in the Northern Hemisphere and the winter in the Southern Hemisphere, the tilt angle of the Earth's jujube sedan axis makes it possible to see the Sun at its highest position in the Arctic Circle. The Tropic of Cancer is the place where the latitude on both sides of the equator is degrees, and the direct point of the sun is located on the Tropic of Cancer.

Suppose that at an observation point on the Tropic of Capricorn, when the solar altitude at noon (i.e., 12 noon local time) is h degrees, the angle between the Sun and the meridian where the observation point is located is 90 degrees-h degrees. Similarly, at an observation point on the Tropic of Capricorn, when the solar altitude at noon is also h degrees, the angle between the Sun and the meridian of the observation point is also 90 degrees-h degrees. At any point between the Tropic of Cancer and the Tropic of Capricorn, when the solar altitude at noon is h degrees, the angle between it and the finger difference of the meridian where the observation point is located can be expressed as:

The rotation of the Earth at 90°-h is a continuous process, so in fact this angle is changing. However, in the entire Tropic of Cancer of Hengzao, this change is negligible due to the relatively slow rotation speed of the earth and the short distance. Therefore, at any point between the Tropic of Capricorn, the only reason why the actual solar altitude at noon is equal to "180 degrees - h" is the relationship between this angle and perpendicular to the ground (i.e., the actual solar altitude is 90 degrees).

1) Reading the map, a is the summer solstice, b is the autumn equinox, c is the winter solstice, d is the spring equinox 2) when the earth turns to a, the sun shines directly on the Tropic of Capricorn, the northern hemisphere has long days and short nights, and the southern hemisphere is winter;

3) When the earth turns and closes to point B, the sunlight shines directly on the equator, and the length of day and night in the northern hemisphere is divided equally between day and night

4) When the earth turns to C, the sunlight directly hits the Tropic of Capricorn, and the shadow of the car at noon is the longest, and the height of the sun is the smallest

5) During Labor Day, the earth is in the d-a part of its orbit, i.e., the vernal equinox and the summer solstice, so the answer is: 1) the summer solstice; Buried on the day of the autumn equinox; Winter solstice; the day of the vernal equinox;

2) Tropic of Cancer; The days are long and the nights are short; Winter;

3) the equator; divestitel;

4) Tropic of Capricorn; Long;

5）d-a．

Like the landlord, I can understand the logic of most people choosing to rise in the southeast: the sun is directly on the Tropic of Capricorn, and the midday sun is located in the south of the sky, so naturally, the morning and dusk sun will also appear in the southerly direction.

Looks pretty right, right? However, there is an implicit idea in this logical chain that the sun's trajectory on Sunday is perpendicular to the horizon circle, which is false.

If this is removed, if the sun's trajectory on Sunday is tilted, even if it is south of the sky at noon, it will still turn to the north of the sky at sunset and sunrise.

In fact, the trajectory of celestial bodies in the area north of the Tropic of Cancer is tilted, and the following is a schematic diagram of the sun's orbit on Sunday:

Unlike judging the nature of the orientation on the earth, it is relatively simple to identify the direction of sunset and sunrise, as long as you know which season and hemisphere you are in, you can determine it according to the law. In this article, we will take the summer solstice as an example to explain how the sun rises and sets during this solar term, and analyze why such a change occurs.

Is the summer solstice the sun rising due east?

No, this solar term summer solstice is the northeast sunrise, and there is a rule here, that is, the period from the spring equinox to the autumn equinox, that is, the summer half of the northern hemisphere, the sun rises and rises from the northeast. It is only on the spring and autumn equinoxes that the sun rises due east and sets due west.

What direction to fall

The day of the summer solstice is at the aphelion, the direct point of the sun is almost at the Tropic of Capricorn, except for the polar day and night regions, the world is the northeast sunrise state slag wheel, the northwest sunset. At this time, the sun rises at noon, so the sun travels the longest on the ground, resulting in the longest days and the shortest nights. Taking China as an example, the day length of Haikou City in Hainan is about 13 hours, Hangzhou City is 14 hours, Beijing is about 15 hours, and Mohe River in Heilongjiang can reach more than 17 hours.

Therefore, in the vicinity of Mohe, you can see a very late sunset, and it seems that after three or four hours, it is time to write letters in the daytime.

What is the reason for this

This is due to the revolution of the earth, i.e., it revolves around the sun. In the summer of the Northern Hemisphere, for example, when the North Pole is tilted towards the Sun, the Northern Hemisphere receives sunlight for a longer time, which means that the Sun rises earlier than 6 o'clock, which inevitably delays the sunset, allowing the Sun to stay in the sky for more than 12 hours. The Sun moves once every 24 hours on the celestial sphere (a solar day), and more than 12 hours of daytime means that the Sun will move more than 180° in the sky, and the Sun will be due south at 12 o'clock, so the direction of the sun's rise will be north-east.

The direct point of the sun at the Tropic of Cancer is the summer solstice, and the Tropic of Cancer is the winter solstice.

Taking China (Northern Hemisphere) as the benchmark, the vernal equinox is around March 21, when the sun shines directly on the equator, that is, the 0 degree latitude;

June 22 is the summer solstice, when the sun shines directly on the Tropic of Capricorn, that is, the northern latitude;

The autumnal equinox is around September 21, when the sun shines directly on the equator, that is, the 0 degree parallel;

The winter solstice is around December 22, when the sun shines directly on the Tropic of Capricorn, which is the southern latitude.

During the period between the spring equinox and the summer solstice, the direct sun point continuously moves from the equator to the Tropic of Capricorn, from the summer solstice to the winter solstice, from the Tropic of Cancer to the Tropic of Cancer (the sun hits the equator directly at the autumnal equinox), and from the winter solstice to the spring equinox, the direct solar point continues to move from the Tropic of Cancer to the equator.