What kind of weather phenomena we observe are natural phenomena under what circumstances.

Our earth is surrounded by the atmosphere. All kinds of "weather phenomena" we observe are natural phenomena that occur in the atmosphere.

The weather process is the change process of weather phenomena with time in a certain area. All kinds of weather systems have certain time and space scales, and they are intertwined and influence each other.

The combination of many weather systems constitutes a large-scale weather situation and hemispheric and even global atmospheric circulation. The weather system is always in the process of rebirth, development and extinction, and there are corresponding weather phenomena in different development stages.

Extended data

Characteristics of the atmosphere:

The temperature of (1) decreases with the increase of height: this is because this layer can not directly absorb the short-wave radiation of the sun, but can absorb the long-wave radiation reflected from the ground and heat the atmosphere from the underlying surface. So the air near the ground is heated more, and the air far from the ground is heated less. With every increase of 1 km, the temperature drops by about 6.5 degrees.

(2) Air convection: Because the surface of lithosphere and hydrosphere is heated by the sun, the lower air is heated by thermal radiation, vertical convection occurs between cold and hot air, and because the ground is divided into land, sea, day and night and latitude, the temperature in different regions is different, forming a horizontal movement of air.

(3) The horizontal distribution of temperature, humidity and other factors is uneven: the atmosphere is in contact with the surface, and toxic substances produced by human activities enter the air layer, so in addition to the vertical and horizontal movement of airflow, the chemical process in this layer is very active, the air mass becomes cold or hot, and water vapor forms a series of weather phenomena such as rain, snow, hail, frost, dew, clouds and fog.