What are the occurrence time and climatic conditions of inversion layer?

1: radiation inversion The inversion caused by intense radiation on the ground is called radiation inversion. On a clear, windless or breezy night, the ground becomes cold due to radiation, and the air layer near the ground is the strongest, while the upper air cools slowly, resulting in the inversion of the lower atmosphere. Generally speaking, the radiation inversion gradually disappears after sunrise.

2. Advection inversion The inversion caused by warm air flowing to the cold ground is called advection inversion. When warm air flows to the cold ground, there is constant heat exchange between the warm air and the cold ground. The lower layer of warm air is most affected by the cold ground, and the temperature drop is the strongest, while the upper layer cools slowly, forming an inversion. The intensity of advection inversion is mainly determined by the temperature difference between warm air and cold ground. The greater the temperature difference, the stronger the inversion.

3. Turbulent inversion The inversion caused by turbulent mixing of low-level air is called turbulent inversion. When the direct reduction rate of air temperature in the gas layer is less than that of dry insulation, the temperature distribution of the gas layer gradually approaches the direct reduction rate of dry insulation after turbulent mixing. The air rising due to turbulence reduces its temperature according to the direct reduction rate of dry insulation. When the air rises to the top of the mixed layer, its temperature is lower than the surrounding air, and the temperature of the upper air decreases due to mixing. When the air sinks, the situation is just the opposite, resulting in a lower temperature rise. Therefore, in the turbulent weakening layer, inversion occurs.

4. In the settlement inversion, the inversion caused by the whole layer of air sinking is called settlement inversion. When an air layer sinks, the thickness of the air layer decreases due to the gradual increase of air pressure and the horizontal diffusion of the air layer. If the sinking process of the air layer is adiabatic and the relative position of air in the air layer remains unchanged, the sinking distance at the top of the air layer is greater than that at the bottom, resulting in the adiabatic temperature rise at the top of the air layer greater than that at the bottom (H > H > H' in the figure). When the gas layer sinks to a certain height, the temperature at the top of the gas layer is higher than that at the bottom, resulting in inversion. Settlement inversion mostly occurs in areas controlled by high pressure, with wide range, thick inversion layer and long inversion duration.

5. The front inversion front is a narrow transition zone between cold and warm air masses, with warm air masses above the front and cold air masses below. In the transition zone of cold and warm air mass, inversion is formed.

In nature, the formation of inversion is often the result of many reasons. No matter how the inversion is formed, as long as it occurs, it will have a certain impact on the weather. The inversion layer will hinder the vertical movement of air. Lots of smoke, steam, etc. Gathering under the inversion layer will make the visibility worse and easily cause air pollution.

What are "inversion layer" and "inversion layer"

When it comes to inversion, many people are not familiar with it. However, the abnormal weather changes caused by inversion layer have great influence on people's production and life, and even bring great harm to people's lives and property, which many people have already understood.

In the morning or evening of winter and spring, in cities and suburbs, it is often seen that smoke floats horizontally and spreads everywhere after rising to a certain height. If there is no wind and the temperature drops sharply, the whole field of vision will soon become blurred. With the coming of smog, the weather is gloomy and the sun is dim, which makes people breathless, and at the same time, they will smell unpleasant smells such as soot. People with poor physical resistance will feel chest tightness.

What are inversion layer and inversion layer? Generally speaking, in the lower atmosphere, the temperature usually decreases with the increase of altitude, but sometimes the opposite situation may occur in some layers, and the temperature increases with the increase of altitude. This phenomenon is called inversion. The atmosphere with inversion phenomenon is called inversion layer.

There are several main reasons for the formation of inversion layer: first, radiation cooling on the ground; Second, air advection cooling; Third, the air sinks and heats up; The fourth is the turbulent mixing of air; The fifth is the inversion formed on the front. According to different reasons, the inversion layer can be divided into radiation inversion layer, advection inversion layer, sinking inversion layer, frontal inversion layer and turbulent inversion layer. But no matter which inversion layer, it has a certain impact on the weather.

In the inversion layer, the warmer and lighter air is located above the colder and heavier air, forming an extremely stable air layer, just like a pot cover, which seriously hinders the convective movement of air. Because of this, there is no way for water vapor, smoke dust and various harmful gases in the air near the inversion layer to float in the air layer below the inversion layer, which is beneficial to the formation and reduction of clouds. It has brought trouble to transportation, and more seriously, it has hindered the timely diffusion of pollutants in the air, aggravated air pollution, and brought harm to people's lives and property. More than half of the major public hazards in the modern world are related to the influence of inversion layer.

The inversion layer is very harmful to people's health. In order to avoid its adverse effects as much as possible, protect the human environment and safeguard the safety of people's lives and property, on the one hand, we must know the inversion layer in the lower atmosphere in detail, find out its regularity, and provide reliable meteorological basis for the prevention and control of air pollution. On the other hand, we must take necessary measures to try our best to prevent the inversion layer, which means reducing or eliminating pollution sources and vigorously planting trees, grasses and flowers.