What does the weather mean?

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.

Chinese name

weather

Foreign name

weather

meaning

atmospheric condition

belong to

Natural weather phenomenon

affect

Important indicators of family and travel

quick

navigate by water/air

cloud

fog

rain

snow

Frosty/frosty powder

weather symbol

tornado

history

weather forecast

wind

The cause of wind

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. [ 1]

wind

atmospheric pressure

It can be defined as 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.

The influence of the wind

Wind is one of the environmental factors of agricultural production. Moderate wind speed plays an important role in improving farmland environmental conditions. The increase of wind speed accelerates or strengthens the surface heat exchange, evapotranspiration of farmland and the transportation of carbon dioxide and oxygen in the air. Wind can spread plant pollen and seeds and help plants pollinate and reproduce. Wind energy is widely distributed and inexhaustible. Monsoon prevails in China, which is beneficial to the growth of crops. Inner Mongolia Plateau, Northeast Plain, Southeast Coast and Inland Mountainous Area are rich in wind energy resources, which can be used as energy sources.

Wind will also have a negative impact on agriculture. It can spread pathogens and plant diseases. High-altitude wind is a meteorological condition for the long-distance migration of pests such as armyworm, rice planthopper, rice leaf roller and locust. Strong wind causes mechanical wear of leaves, lodging of crops, broken trees, falling flowers and fruits, which affects the yield. Strong winds can also lead to soil erosion and sand dune movement, and destroy farmland. Blindly reclaiming wasteland in arid areas, wind will lead to land desertification. Strong winds and snowstorms in pastoral areas will disperse herds and aggravate freezing damage. Some special properties of local winds often cause wind disasters. Tidal wind with high salinity, scorching wind with high temperature and low temperature, and dry-hot wind blowing from the sea have seriously affected the flowering and fruiting of fruit trees and the filling of cereal crops. In order to prevent wind damage, wind-resistant varieties with dwarfing, lodging resistance and friction resistance are usually cultivated. It is more effective to build windbreaks and set up windbreaks.

wind energy

The kinetic energy formed by airflow is wind energy. Wind energy is a conversion form of solar energy.

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weather

The radiation of the sun causes uneven heating of the earth's surface, uneven distribution of atmospheric pressure, and the air moves along the horizontal direction to form wind. The formation of wind is the result of air flow. The formation of wind energy utilization is mainly to convert the kinetic energy of atmospheric movement into other forms of energy. In the equatorial and low latitudes, the solar altitude angle is large, the sunshine time is long, the solar radiation intensity is strong, the ground and atmosphere receive more heat and the temperature is high; At high latitudes, the solar altitude angle is small, the sunshine time is short, the heat received by the ground and the atmosphere is less, and the temperature is low. This temperature difference between high latitude and low latitude forms a north-south pressure gradient, which makes the air move horizontally and the wind blows along the direction of the horizontal pressure gradient, that is, the vertical and isobars blow from high pressure to low pressure. The earth is spinning, and the force that deflects the horizontal movement of air is called geostrophic deflection force, which deflects the airflow in the northern hemisphere to the right and the airflow in the southern hemisphere to the right, so the atmospheric movement of the earth is not only affected by the pressure gradient force, but also by geostrophic deflection. The real motion of the atmosphere is the result of the comprehensive influence of these two forces.