Snow is formed by the direct condensation of water vapor in the atmosphere or the direct solidification of water drops, because clouds are composed of small water drops and ice crystals. When the temperature is very low, the small ice crystals in the clouds will melt when they collide with each other, and then freeze again. After repeated several times, the ice crystals will increase. When the small ice crystals grow to overcome the resistance and buoyancy of the air, they will fall to the ground to form snow.
There has been a saying circulating on the Internet that “Beijing where it snows becomes Peiping, and Suzhou where it snows becomes Gusu”. Just thinking about it is very beautiful, but who knows how such beautiful snow is formed? Today I will explain to you.
Snow is a natural phenomenon in which water or ice condenses in the air and then falls, or refers to falling snowflakes; snow is a form of water in the solid state, which will only appear under the influence of temperatures below zero degrees Celsius and extratropical cyclones. The chance of snow in tropical regions and tropical regions is less.
Most snowflakes are hexagonal. The reason for the variety of patterns is that the number of ice molecules is mostly hexagonal. For hexagonal flake ice crystals, due to their different curvature on the surface, edges and corners, they have different saturated water vapor pressures. Among them, the saturated water vapor pressure on the corners is the largest, that on the edges is the second, and that on the plane is the smallest.
Snow is conducive to the growth and development of crops; snow is a good insulation effect, can protect plants from frostbite in winter, next spring snow water melt can provide good water supply for vegetation, the power of nature is not coincidence, because snow thermal ability is poor, soil surface covered with a layer of snow, can reduce soil heat, block the invasion of cold, so snow protected crops can be safe for the winter.
Snow also saves water for crops; In addition, snow can also enhance soil fertility, according to the determination, every 1 liter of snow water, about 7.5 grams of nitrogen compounds, snow water into the soil is equal to a nitrogen fertilizer; Using snow water to feed livestock and poultry, irrigate crops can receive obvious benefits.
Due to the different sizes, shapes, and density of snowflakes falling on the ground, snow is measured by the water after snow melts: snowfall is divided into four grades: light snow, moderate snow, heavy snow and blizzard: light snow 0.1 ～2.4 mm/day, moderate snow 2.5～4.9 mm/day, heavy snow 5.0～9.9 mm/day, blizzard greater than or equal to 10 mm/day.