autumn. Dewdrops are water drops that condense into small ice crystals when the water vapor near the ground at night or early in the morning is cooled, and then melt on objects. The temperature difference between day and night in spring and autumn is relatively large. It may be very hot during the day but very cold at night, which is very conducive to the formation of dew. Especially in autumn, there are many dewdrops, so dewdrops are usually used to refer to autumn. Bailu is a solar term named after the dew in autumn.
What is dew:
Dew, that is, rain falling on leaves, flowers and grass. The cause and process of dew formation are the same as that of frost, except that the temperature at which it forms is above 0 ° C. Shiny, transparent and round.
Formation process of dew:
The formation of dew is because the hot air is saturated when it meets the object with lower temperature, and condenses into small droplets to stay on the object. Above 0 ° C, the temperature when the air reaches water vapor saturation due to cooling is called "dew point temperature". In the warm season, when the ground object is strongly radiated and cooled at night, the air temperature in contact with the object surface decreases. After it falls to the "dew point", there is excess water vapor. Because the temperature is above 0 ° C, these excess water vapor condenses into water droplets and adheres to the ground object, which is dew.
Dew generally forms at night. After sunrise, when the temperature rises, the dew evaporates and disappears, and the existence time is very short.