What are the latitudes of beginning of spring, Changxia, beginning of autumn, beginning of winter and Sun Point?
With regard to the point of direct sunlight, taking the long summer as an example, the direct sunlight is 45 degrees, because sinx = sink sint, where k = 23 26' and t = 45, from which x =-16 20' is obtained.
In addition, the direct direction of Changxia and beginning of autumn is16 20' s, and that of beginning of spring and beginning of winter is16 20' n.
Extended data
Law of activity
The direct point of the sun moves westward every hour, passing through longitude 15 degrees every hour. In the calculation of geography problems, we can roughly take the latitude of moving 0.25 degrees every day.
At the vernal equinox, the direct point of the sun is on the equator, and then it moves northward until it reaches the Tropic of Cancer on June 22nd (that is, the summer solstice).
On the summer solstice, the direct point of the sun is on the tropic of cancer, and then it moves south until it reaches the equator on September 23 (autumnal equinox). ?
At the autumnal equinox, the direct point of the sun is at the equator, and then it continues to move southward until it reaches the tropic of Capricorn (that is, the winter solstice) on February 22, 65438. ?
On the solstice in winter, the direct point of the sun is on the tropic of cancer, then it moves northward and returns to the equator on March 2 1 day (that is, the vernal equinox). ?
The cycle of this repeated regression movement is 365 days, 5: 48: 46, that is, about 365.2422 days, which is called the tropic of cancer. ?
According to Kepler's law, the earth revolves around the sun in an elliptical orbit, and the sun is at a focus of the ellipse, so perihelion and apohelion appear! With the sun as the center, the area swept by the earth in unit time is equal.
The northern hemisphere is apohelion after July, with long days and short nights, while the southern hemisphere is the opposite.
January is perihelion, with short days and long nights.
65438+1The perihelion distance at the beginning of October is 1.4765438+ 1 100 million kilometers, the angular velocity is 6 1 minute, and the antenna speed is 30.3 kilometers per second.
At the beginning of July, the distance between the sun and the earth at apohelion was 1.5265438+ 1 100 million kilometers, with an angular velocity of 57 minutes/day and a linear velocity of 29.3 kilometers/second.
Perihelion is fast, the sun is far away and the sun is slow.
The length of day and night
Every year on March 2 1 or so, the vernal equinox is long day and night.
Every year around June 22nd, the summer solstice is long and the night is short (northern hemisphere).
Every year around September 23rd, the autumnal equinox is long day and night.
Every year around 65438+February 22nd? Winter solstice has short days and long nights (northern hemisphere)
The equator is equal day and night all year round.
Reference link source: Baidu Encyclopedia-direct drying point