What are the factors that affect temperature?

1. Natural factors

In addition to the periodic changes caused by changes in solar radiation, the temperature in a certain place also has non-periodic changes caused by the movement of the atmosphere. The change in actual temperature is the result of the simultaneous effects of these two aspects. If the former has a large effect, the temperature will show periodic changes; on the contrary, it will show non-periodic changes. However, judging from the general trend and most situations, the periodicity of diurnal and annual changes in temperature is still dominant.

Each component in the heat balance, such as radiation difference, latent heat and sensible heat exchange, is affected by different control factors. These factors such as latitude, season and other astronomical factors have obvious zonal and periodic characteristics. The nature of the underlying surface, the height of the terrain, and weather conditions, such as cloud cover, atmospheric dryness and humidity, etc., all have non-zonal characteristics. At the same time, the influence of these factors is also different in different locations, so the temperature distribution caused by changes in the heat budget is also uneven.

2. Human influence

1. Influence of the characteristics of the urban underlying surface (the contact surface between the bottom of the atmosphere and the ground surface)

A large number of artificial structures in the city such as pavements Installed floors, various building walls, etc., change the thermal properties of the underlying surface. The urban surface contains less water, and more heat enters the air in the form of sensible heat, causing the air to heat up. At the same time, the urban surface has a higher absorption rate of sunlight than the natural surface and can absorb more solar radiation, which in turn causes the air to gain more heat and increase the temperature.

2. Urban air pollution

Motor vehicles, industrial production and a large number of crowd activities in cities produce large amounts of nitrogen oxides, carbon dioxide, dust, etc. These substances can The earth absorbs the energy of thermal radiation in the environment, producing the well-known greenhouse effect, causing further warming of the atmosphere.

3. The impact of artificial heat sources

Factories, motor vehicles, residents' lives, etc., burn various fuels and consume a lot of energy. Countless stoves are burning and emitting heat.

4. The natural underlying surface in the city has decreased

The number of buildings, squares, roads, etc. in the city has increased significantly, and natural factors such as green spaces and water bodies have correspondingly decreased, releasing more heat. , there is less heat absorption, and the ability to alleviate the heat island effect is weakened.

Extended information:

Since temperature affects physical quantities such as volume, density, sound speed, impedance, etc., temperature can be measured by measuring changes in the values ??of these physical quantities. There are currently dozens of temperature measurement methods, which can be divided into the following categories according to the measurement principles:

1. Expansion thermometry uses geometric quantities (volume, length) as markers of temperature. For example, the measuring range of a mercury thermometer is about -30~300°C, and the measuring range of an alcohol thermometer is about -115~110°C.

2. The electrical thermometer method uses certain thermometers that change with temperature. Electrical quantities such as resistance serve as markers of temperature. Resistance thermometers are mostly used in situations below 600°C. The measurement range of thermocouple thermometers is generally below 1600°C. In addition, there are semiconductor thermistor thermometers.

3. Magnetic thermometry measures temperature based on the relationship between the magnetic susceptibility of paramagnetic substances and temperature. It is commonly used in ultra-low temperature (less than 1K) measurements.

4. Acoustic thermometry uses the speed of sound as the temperature indicator (the square of the speed of sound is proportional to the temperature). Mainly used for the determination of thermodynamic temperature at low temperatures.

5. Frequency thermometry, which measures temperature based on changes in the natural frequency of an object. Quartz crystal thermometers have a resolution of one ten thousandth of a degree Celsius.

6. Optical thermometry measures temperature based on blackbody radiation. Such as infrared thermometer.

7. Density thermometry, such as Galileo thermometer.

Reference: Baidu Encyclopedia Temperature?