Si Nuo introduced as follows:
Snow, snow is a natural phenomenon, and the water vapor in the air condenses and then falls to the ground. Water is the foundation of all kinds of life on the earth, and its changes and movements have created our world today. On the earth, water is constantly circulating, and the water in the ocean and on the ground is heated and evaporated into the sky.
These water vapor moves to other places with the wind, and when it meets cold air, it forms precipitation and returns to the earth's surface. There are two kinds of precipitation: one is liquid precipitation, which is rain; The other is solid precipitation, which is snow or hail.
The reasons for the snow are as follows:
Snow is a natural phenomenon. Due to the difference of meteorological conditions and growth environment in the sky, all kinds of atmospheric solid precipitation are caused. The names of these atmospheric solid precipitation vary from place to place, from person to person, varied and extremely inconsistent. For convenience, the International Snow and Ice Committee under the International Hydrological Association.
On the basis of consulting experts from various countries, 1949 held a special international conference, at which the proposal of "concise classification of atmospheric solid precipitation" was adopted. This concise classification divides atmospheric solid precipitation into ten types: snowflake, star snowflake, columnar snowflake, needle snowflake, multi-branch snowflake, axial snowflake, irregular snowflake, graupel, ice particle and hail.
The first seven kinds are collectively called snow. Why can't the last three be called snow? It turns out that there are two processes for gaseous water vapor to become solid water. One is that water vapor first becomes water, and then water condenses into ice crystals. Another is that water vapor directly becomes ice crystals without water. This process is called water condensation. Therefore, snow is solid precipitation formed by condensation of water vapor in the sky.
The snow in summer is introduced as follows:
In summer, in mountainous areas, there are often many supercooled water droplets frozen around the crystal nucleus, forming white dark round particles. In meteorology, this kind of thing is called graupel, and in many places, it is called Michelle or snow graupel. Generally, the diameter of graupel is between 0.3 and 2.5 mm, which is brittle and easy to break.