Why is the height of the sun the same everywhere on the same parallel?

Why is the morning and dusk line tangent to the weft coil?

Owner: The morning and dusk line is the great circle of the earth, and the center of the circle coincides with the central axis of all parallels--- so it is tangent to the parallel.

If there is a polar night phenomenon near the tangent point, then the meridian where the tangent point is located is 12 o'clock when the local time?

Landlord: The tangent point always corresponds to the height of the sun at noon, so the local time ratio is 12 o'clock and the latter is 0 o'clock (that is, 24 o'clock); There is a polar night phenomenon near the tangent point, and the ratio is 12 o'clock.

If it's a polar day, it's 0 or 24 o'clock?

Landlord: 0:00 (that is, 24 o'clock).

Why sunrise time + sunset time = 24 ?

Landlord: Sunrise time + sunset time is equal to one rotation of the earth (i.e., one solar day), one solar day = 24 hours.

Hope it helps!

Personal declaration: I am HK - Honest King - Honest King, not the English abbreviation of Hong Kong, remember to remember ......

This sentence is wrong, it should be the same as the noon sun altitude angle on the same parallel.

The problem is more specific, one less condition seems to be, it is impossible to judge the meridian where the tangent point is located at 12 o'clock when the place is 12 o'clock, sunrise time + sunset time = 24, you will know the time.

12 + half of daylight hours = sunset.

0 + half of the night time = sunrise.

To be precise, it should be the same latitude, the same time in different regions, and the same altitude angle of the sun in all places.

The height of the sun at noon is based on the difference between the geographical latitude of the place and the latitude of the direct point. The latitude is the same, and the latitude of the point of direct light is known, so the height of the sun at noon must be the same.

The length of day and night is determined according to the intersection of the morning and dusk lines and the weft coils, after the intersection there is a period in the day and a period in the night, then on the same parallel, the day section is the same, and the night section is also the same, so on the same latitude line, the length of day and night is the same.

Sun altitude angleThe relationship with latitude is: solar altitude angle = 90° - local latitude withThe point where the sun shines directlyThe difference in latitudeAbsolute

The solar altitude angle is calculated as h=90°-|where h is the solar altitude angle, and the geographic latitude of the observation site is expressed by , the declination of the sun.

equal latitude to the point where the sun shines directly) is expressed in δ. Therefore, the solar altitude angle = 90° - the absolute value of the difference between the local latitude and the latitude of the point where the sun shines directly.

For example, at a certain time, the latitude of the point where the sun is shining directly is 15 degrees, and the latitude of a certain place is 40 degrees, then the solar altitude angle = 90 - (40-15) = 65 degrees.

At the same time, the following observation points reported the following number of solar altitude angles:

2°N s (2° from the point of direct sunlight): 88°=90° 2°.

3°N s (3° from the point of direct sunlight): 87°=90° 3°.

10°N S (10° from the point of direct sunlight): 80°=90° 10°.

30°n s (30° from the point of direct sunlight): 60°=90° 30°.

80°N S (80° from the point of direct sunlight): 10°=90° 80°.

90°n s (90° from the point of direct sunlight): 0°=90° 90°.

The relationship between the solar altitude angle and the latitude: the solar altitude angle = 90°-|Local latitude The latitude of the point where the sun shines directly|.

The altitude angle of the sun at noon, the latitude of the direct point of the sun, and the latitude of the earth, any two of these three variables can be found to find the third. For example, the solar elevation angle at noon on the summer solstice (23°26 N) in Beijing (40°N) a, a=90°-(40°-23°26)=73°26.

The solar elevation angle is the angle between the sun's rays in a place and the surface slice that is connected to the center of the earth through that place. When the solar altitude angle is 90°, the solar radiation intensity is the highest. The greater the degree to which the Sun obliquely hits the ground (i.e., the smaller the solar altitude angle), the less intense the solar radiation.

The law of change. 1. The law of latitude change: the latitude and longitude where the direct sun point is located decreases to the north and south.

It can be inferred that the latitude difference from the direct point of the sun is one degree, and the altitude angle of the sun at noon decreases by one degree. (It can be further concluded that the altitude angle of the sun at a certain noon is known, and there are generally two parallels equal to this degree).

For example, if the sun shines directly at 20°N, the elevation angle of the Sun at noon in the world will gradually decrease from 20°N to the north and south, and the solar elevation angle at noon at 19°N is equal to 89°.

That is, the height of the sun at noon at 19°n = 90° - (direct point of the sun - latitude of the place) = 90° - (20° - 19°) = 89°

2. The law of seasonal changes: the direct sun point gradually increases when it moves, and gradually decreases when it moves (the direct sun point is relative to the latitude of a certain place). For example:

For regions at 31°N, the solar elevation angle increases at noon from December 22 (winter solstice) to June 22 (summer solstice), and decreases at noon from June 22 (summer solstice) to December 22 (winter solstice).

The higher the latitude, the smaller the maximum noon digging of the sun, and the minimum solar altitude is 0 degrees.

For example, when the sun shines directly on the equator, the noon solar height of 80 degrees north latitude is 10 degrees, the minimum is 0 degrees, and the diurnal variation is 10 degrees; At 20 degrees north latitude, the noon sun height of Qiqiao is 70 degrees, the smallest is 0 degrees, and the daily variation is 70 degrees; The height of the Sun at noon at the equator is 90 degrees, the minimum is 0 degrees, and the diurnal variation is 90 degrees.