Sunrise refers to what the sun looks like when it first rises above the horizon or is first seen. Generally, it refers to the time when the sun rises slowly from the eastern horizon, but it is actually defined as the moment when the sun just appears on the horizon, not the moment when the whole sun leaves the horizon.
Principle At sunrise, sunlight is Rayleigh scattered by dust in the earth's atmosphere, so the sky will be filled with smog, but the smog at sunrise is more elegant than at sunset, because there is less dust in the atmosphere at sunrise than at sunset.
The time of sunrise will change with the season and the latitude of different places.
1. Traditionally, people think that the latest sunrise time is the winter solstice in the northern hemisphere, but in fact, the latest sunrise time should be 65438+1early October.
In the same way, the earliest sunrise on the solstice is not in summer, but in early June. Even in the equatorial region, the time of sunrise and sunset will change a little during the year, and these changes can be expressed by daily trajectory.
3. The time of sunrise and sunset can be calculated by tracking the trajectory of the sun, but the calculated time will be slightly different from the real feeling, the calculated sunshine time will be longer than the real feeling, and the calculated night time will be shorter than the real feeling.