Can I watch the sunrise on cloudy days?

Of course. Cloudy weather is between sunny and cloudy. In meteorology, it means that the cloud coverage in the sky accounts for four-tenths to eight-tenths of the sky. Be careful of ultraviolet rays when you are active in cloudy weather. Ultraviolet ray is the general name of radiation with the wavelength from 10 nm to 400 nm in the electromagnetic spectrum, which can't be detected by human eyes, but too much ultraviolet ray may harm eyes.

The German Good Vision Association reminds that in cloudy summer, people should not forget to protect sensitive eyes, because some ultraviolet rays can still reach the surface through clouds, and long-term use may cause certain damage to eyes.

Extended data

Sunrise principle: At sunrise, due to the influence of dust in the earth's atmosphere, sunlight is scattered by Rayleigh, 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. Traditionally, in the northern hemisphere, the sunrise time from winter solstice is the latest, but in fact, the latest sunrise time should be 65438+1early October.

By the same token, 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. These changes can be represented by daily trajectories.

The time of sunrise and sunset can be calculated by tracking the sun's trajectory, 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.

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