climatic elements

Climate elements are basic physical quantities and basic weather phenomena used to explain the atmospheric state, also known as meteorological elements. Such as air pressure, temperature, humidity, wind direction and speed, precipitation, thunderstorm, fog, radiation, cloud cover and so on. Atmospheric pressure: Atmospheric pressure is the pressure generated by the movement of air molecules on any surface unit area.

Chinese name

climatic elements

Foreign name

Main weather factors

atmospheric pressure

atmospheric pressure

temperature

atmospheric temperature

Scientific and technological definition

English Name: Climatic Elements

Chinese name: climatic elements

Definition: 1: a parameter that characterizes a climate feature or state. Such as temperature, precipitation, wind, etc.

Applied discipline: atmospheric science (first-class discipline);

Climatology (two disciplines)

Definition 2: A parameter that describes a climate feature or state. Such as temperature, precipitation and air pressure.

Applied discipline: geography (first-class discipline);

Climatology (two disciplines)

nominal definition

Climate: the weather characteristics of a region in a long period of time (more than 30 years). Including ordinary weather conditions and extreme weather conditions. Relatively stable, such as Guangdong province, the annual average temperature 19 ~ 26℃, the extreme minimum temperature -7? 3℃, the extreme maximum temperature is 42℃, which belongs to subtropical tropical humid monsoon climate. It is determined by solar radiation, atmospheric circulation, geographical factors and human activities.

Elements: ① Essential elements of things: Vocabulary is the basic element of language | People, environment and plot are the three elements of writing a novel. ② The basic unit of the system. It is hierarchical. An element is relative to the system in which it is located, and it is relative to the system of the elements that make it up. In the system, they are independent of each other and connected in proportion to form a certain structure, which largely determines the nature of the system. The nature, position and function of the same element in different systems are different. If an element in the system is too different from other elements, it will be separated or cleared by itself.

Basic overview

Climate main factor is a parameter that represents the climate characteristics or state of a specific place and a specific time period. In a narrow sense, climate elements are meteorological elements, such as temperature, humidity, air pressure, wind, clouds, fog, sunshine and precipitation. These parameters are the basic items observed by weather stations at present. Climate elements in a broad sense also include parameters with energy significance, such as solar radiation, surface evaporation, atmospheric stability, atmospheric transparency and so on. Temperature, precipitation and light have great influence on the growth, distribution of animals and plants and human activities. According to the generalized climatic factors, we can infer the thermal and dynamic conditions of climate and deepen our understanding of the climatic conditions in a certain area.

Main meteorological elements

Air pressure: the pressure of the atmosphere is the pressure generated by the movement of air molecules on any surface unit area.

Temperature: the temperature of the atmosphere, indicating the degree of heat and cold of the atmosphere. It is the average kinetic energy of air molecular motion. The general unit is celsius, or thermodynamic temperature K.

Atmospheric humidity (humidity for short): indicates the water vapor content or humidity degree in the air, which can be expressed by physical quantities such as specific humidity (G), absolute humidity (pv), water pressure (E), dew point and relative humidity.

Wind: the movement of air relative to the ground. Meteorology often refers to the horizontal movement of air, expressed by wind direction and wind speed. Wind is a vector with magnitude and direction. Wind direction refers to the direction of the wind. Wind speed refers to the distance that air moves in the horizontal direction in unit time, and the unit is meter/second or kilometer/hour. (0- 12)

Cloud: a visible polymer consisting of a large number of water droplets and ice crystals suspended in the air. In routine meteorological observation, the shape, height and amount of clouds should be determined.

Precipitation: refers to liquid water and solid water falling from the clouds, such as rain, snow and hail.

Evaporation: evaporation on the surface of a liquid. Meteorology refers to the process of water changing from liquid to gas.

Radiation: the process of sending energy or material particles from a radiator to all directions in space. In meteorology, solar radiation is usually called short-wave radiation, while earth surface radiation and atmospheric radiation are long-wave radiation.

Sunshine: the time when the sun shines. Meteorology usually provides the observed actual light time.

Visibility: refers to the lowest horizontal distance, in meters or kilometers, that a person with normal vision can see or identify the target (black, high humidity and low humidity) from the sky background at that time. Visibility indicates the cleanliness and transparency of the atmosphere. Observed values are usually divided into 10 levels.

Air humidity: the humidity of the air is referred to as air humidity for short, which reflects the amount of water vapor in the atmosphere and the humidity of the air.

Commonly used expressions are: absolute humidity, water vapor pressure, relative humidity, saturated air pressure, dew point, etc.

(1) Absolute humidity: the mass of water vapor per unit volume (1m3) (kg). From the ideal gas state equation, we can get:

(2) Relative humidity: the ratio of absolute humidity ρw of air to absolute humidity ρv of saturated air at the same temperature. It is equal to the percentage of water vapor partial pressure Pw of air and water vapor partial pressure Pv of saturated air at the same temperature.

(3) Water content: The water vapor mass (kg) contained in wet air 1kg dry air also becomes the specific humidity in meteorology. It is equal to the water vapor mass (kg) divided by the dry air mass kg.

Dew point or frost point cools the air near the plane of pure water (or pure ice) to saturation temperature without changing the air pressure and mixing ratio.

The difference between the saturated vapor pressure of undersaturated air at a certain temperature and the actual vapor pressure at that time. Its unit is the same as that of air pressure.