According to the apparent motion diagram of the sun, when the sun shines directly into the northern hemisphere, the global sun rises in the northeast and sets in the northwest except in the extreme areas of day and night. When the sun shines directly in the southern hemisphere, the global sun rises in the southeast and sets in the southwest, except in the extreme areas of day and night; On the equator, except the north and south poles, the global sun rises and sets in the west.
Extended data:
1, the size of sunrise azimuth in equatorial region.
(1), Calculation of the Azimuth of Sunrise from the Summer solstice at the Equator.
As shown in the figure:? * Tropic of Cancer ∴∠∠1= 23 26'
The auxiliary line ab is coplanar with the equator and tangent to the equator at the intersection point A between the morning and evening circles.
The angle between straight line ab and light ① is ∠2.
All solar rays are parallel to each other, ∴∠ 2 = ∠1= 23 26'
Geographical significance of ∠ 2 = 23 26': During the summer solstice, the sunrise in the equatorial region is 23 26' in the northeast.
② Inference:
The degree of the sunrise azimuth (the angle of the sunrise azimuth deviating from the due east) in the equatorial region is equal to the latitude degree of the direct point of the sun.
In the equatorial region, during the winter solstice, the direct sunlight is 23 26', the sunrise azimuth is 23 26', and the sunrise azimuth is 23 26' in the southeast.
During the Spring and Autumn Period, the sun shone directly on the equator, and the sunrise azimuth was 00, and the sunrise azimuth was due east.
2. Variation law of sunrise azimuth at other latitudes.
(1), calculation of sunrise azimuth at other latitudes from summer to day.
As shown in fig. 2, the auxiliary lines cd and ef are coplanar with latitude circle A and latitude circle B, respectively, and the intersections C and D of the meridian at 6 o'clock local time with latitude circle A and latitude circle B are tangent to latitude circle.
The included angle between the straight line cd and the light ②' is < 3.
∵ All solar rays are parallel to each other, and latitude circles are parallel to each other.
∴∠3=∠2=23 26′。
∠ 3 = 23 26' Geographical significance: During the summer solstice, at 6: 00 local time on latitude circle A, the included angle between sunlight and local meridian is 23 26'.
Similarly, during the summer solstice, at 6: 00 local time in latitude circle B, the angle between the sunlight and the local meridian is 23 26', which is not the position of the sun at sunrise in latitude circles A and B.
The included angle between the ray ② and the tangent c ′ d ′ of latitude circle A is the azimuth of latitude circle A at sunrise, which is obviously greater than 23 26 ′.
On the Arctic Circle P, light ③ shines from due north, where the sunrise direction deviates from due east by 90.
2. Inference:
In other areas outside the equator, the azimuth of sunrise is greater than the latitude of the direct point of the sun.
The higher the latitude, the greater the deviation angle. The area where the daytime phenomenon occurs deviates from due east by 90, and the sun rises from due north (or due south).
The direction in which the sun rises and sets on the horizon varies with seasons and latitudes. The declination of sunrise and sunset points refers to the declination of sunrise and sunset points relative to due east and due west respectively.
On the same day, the higher the latitude, the greater the sunrise position.
(Note: the azimuth of equatorial sunrise is always equal to the latitude of the direct point of the sun); At the same latitude, vernal equinox and autumnal equinox, the azimuth of sunrise is 0; The greater the latitude of the direct point, the greater the sunrise azimuth.
In addition, the direct point is in the southern hemisphere (autumnal equinox to vernal equinox), just the opposite. The higher the latitude, the greater the sunrise position.
reference data
Baidu encyclopedia-sun azimuth