Weather refers to the comprehensive reflection of various meteorological elements.

Weather refers to the atmospheric state at a certain moment or within a certain time range comprehensively reflected by various meteorological elements.

Knowledge expansion:

Weather refers to the specific state of the atmosphere near the surface in a short period of time. Weather phenomenon refers to various natural phenomena in the atmosphere, that is, the comprehensive expression of the spatial distribution of various meteorological elements in the atmosphere (such as temperature, pressure, humidity, wind, clouds, fog, rain, flash, snow, frost, thunder, hail, haze, etc.). ) in an instant.

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.

The direct cause of the wind is the uneven distribution of air pressure in the horizontal direction. Wind is comprehensively influenced by different factors such as atmospheric circulation, topography and water area, and its manifestations are various, such as monsoon, local sea-land wind, valley wind and foehn wind.

Simply put, wind is the directional movement of air molecules. To understand the causes of wind, we must first understand two key concepts: air and air pressure.

The components of air include nitrogen molecules (accounting for 78% of the total air volume), oxygen molecules (accounting for about 2 1%), water vapor and other trace components. All air molecules are moving at a very fast speed, colliding with each other and anything on the horizon.

The pressure exerted by air molecules in a given area. Generally speaking, the more air molecules exist in an area, the greater the air pressure in this area. Accordingly, wind is the result of pressure gradient force.

However, some changes in atmospheric pressure are caused by storms, some by uneven surface heating, and some by atmospheric molecules being forced to flow from a relatively high pressure area to a low pressure area in a certain horizontal area. Most of the high-pressure and low-pressure belts shown on the weather map only form a mild breeze that accompanies us.

However, the pressure difference required to generate the breeze only accounts for 1% of the atmospheric pressure itself, and this pressure change will occur in many areas. Relatively speaking, the formation of strong storms stems from the change of larger and more concentrated pressure areas.