Introduction: Haze is naturally the root cause of smog hazards, just like infectious diseases, viruses and bacteria are the root causes! But if there is no transmission route (carrier fog), human beings will not get sick (feel the harm of haze)! Therefore, while eliminating bacterial viruses (haze), should we also wash our hands and pay attention to hygiene (planting trees) to eliminate the transmission route (eliminating and reducing this fog caused by cold air)? ?
the root causes of smog and how to control smog in many provinces such as Beijing, Tianjin and Hebei?
Zhou Qiang
The difference between fog and haze and the generation of haze are two different concepts, but they are all particles floating in the air when the flow force is close to gravity! It's just that fog is tiny water droplets or ice crystals that are saturated with water vapor, but the hydrodynamic force is close to and slightly greater than gravity, and haze is non-aqueous particles such as dust, sulfuric acid, nitric acid and organic hydrocarbons that float in the air due to the hydrodynamic force close to gravity.
so why is this fog generated? I have already said in How Water Molecules Combine and Application of Flow Force of Objects in Meteorology that the combination of water molecules will fall only when the flow force is less than the gravity of water molecules, from the flow force formula F=? k? Tρg? /? P We know that when the temperature decreases, the flow force will decrease, which makes it easy for the flow force to approach gravity. At this time, a large amount of water vapor begins to condense, which means saturation. As long as there is enough water vapor and temperature decrease or a large number of condensation nuclei, it will rain! If there are not enough condensation nuclei and a lot of water vapor, at this time, although the water vapor in the air is saturated, only the fog we see can appear! At this time, the flow force of fog combined with water vapor is close to or slightly greater than gravity and suspended in the air! The temperature is easy to drop in autumn and winter, so this kind of fog is easy to appear in autumn and winter. Fog itself is a normal phenomenon of water vapor condensation, which is not harmful to human body. ? Haze generation is complicated, such as industrial emissions, heating and cooking emissions from families and restaurants, dust, floating dust and smoke from buildings and cars, automobile exhaust and even sand blowing from sandstorms. It is precisely because of the complexity of haze formation that it is harmful to the human body!
However, as the temperature of the haze decreases after the haze is discharged, the flow force decreases, and the gravity of the haze itself will exceed the flow force and settle on the ground, or it will spread and settle elsewhere with the strong wind. Therefore, when there is no fog at ordinary times, the subsidence of haze makes us feel that haze is not so "harmful". Therefore, only when we produce fog in autumn and winter will the smog make people feel "dangerous"! Then why do we feel the harm of haze when there is fog? Because this fog is saturated condensation of water vapor with a hydrodynamic force equal to or slightly greater than gravity, a large number of small water droplets and small ice crystals are suspended in the air, and because hydrodynamic force and gravity are in a state of balance, there is little "wind" and there is not much flow, which is why there are few strong winds in foggy days! Because of fog, a large number of haze substances are attached to or mixed with fog, and there is no way to settle. In addition, there is no flowing "wind", and haze in some areas cannot spread, especially in areas where haze substances are constantly produced (such as around enterprises and roads), it will accumulate more and more, resulting in haze days that endanger human health and life! I won't discuss the harm of haze and smog here, and many articles have introduced it.
Summary:
Fog is not harmful to human body, but haze! But without fog, haze will generally settle down, which is why haze will not be harmful in summer or in foggy weather! Fog is a kind of water vapor condensation phenomenon whose flow force is close to gravity. Once there is fog, the haze will attach to the fog instead of settling, and the harm to human body will increase! Therefore, the report is generally a smog hazard, not a separate one! Once the haze is attached to the fog, it is not easy to disperse. One smog reflects more solar energy, and the fog is not easy to disperse water molecules and condense without enough solar energy (in fact, the general fog will disappear as long as the sun shines). Even if the fog becomes smaller under the irradiation of solar energy, the whole smog is not easy to disperse because of the attached haze! The fog of the three is that the flow force is close to gravity, so it is difficult to form a flow (wind) and it is not easy to spread!
2. What are the root causes of smog in many provinces such as Beijing, Tianjin and Hebei? As can be seen from the above discussion, in order to fundamentally eliminate the harm of smog, we must first put an end to the generation of haze, but this has a great impact on our life and economy, and it is almost impossible to do without haze! In the short term, haze can only be minimized when fog comes, and haze should even be banned in some areas! In the long run, we must meet the needs of life and economy through technological transformation and industrial upgrading and complete public facilities! ? So is there any other way to cure the smog? Smog and haze, in addition to haze, we naturally think of fog! From the above analysis, we know that the harm of smog is the root cause and fog is the carrier of smog! If the occurrence of this carrier fog is reduced, the natural haze will settle on the ground without carrier fog!
so why is it foggy in autumn and winter in Beijing, Tianjin and Hebei? ?
the root cause is the destruction of forests, and the forest destruction in three local areas (coastal Shandong, Beijing-Tianjin-Hebei area along the water vapor transportation, and northwest of the terminal area of water vapor transportation) leads to the foggy reason in Beijing-Tianjin-Hebei area! 1）? The destruction of forests in coastal areas (especially in Shandong) is the fundamental reason for the fog in Beijing-Tianjin-Hebei region. I have already discussed in Why Don't Trees Plant on the Mountains of Shandong: the forests in Shandong Peninsula directly affect the water vapor in the whole Bohai Bay, including Hebei, Beijing, Tianjin, western Liaoning, central Inner Mongolia, northern Henan, Shanxi and northwestern Shaanxi, and Shandong is the upwind place that directly affects the water vapor transportation in Beijing, the capital of China, and it is the coastal area that is the easiest to restore forests! ? As long as the coastal Shandong forest is restored, the water vapor in the whole Bohai Sea region will be solved, which will play a fundamental role in Beijing's water resources, drought, dust and smog control! Turn left | turn right Figure 1: There is no forest in the whole Shandong Peninsula
From the picture, there is almost no green forest in the whole Shandong Peninsula. He and the Korean Peninsula (not even the forest on the Korean Peninsula) almost locked up a large amount of Pacific water vapor passing through the Yellow Sea and could not be transported to the inland Beijing-Tianjin-Hebei region for rainfall, especially in autumn and winter, because there is no forest in Shandong, a large amount of ocean water vapor can not enter the Beijing-Tianjin-Hebei region, so that the conditions for rainfall in this region can only form fog, and at the same time, cold air from the northwest quickly enters
Therefore, in order to fundamentally solve the fog problem in Beijing-Tianjin-Hebei region (drought is also the reason), it is necessary to restore the forest in Shandong to more than 51% and transport a large amount of Pacific water vapor passing through the Yellow Sea to Beijing-Tianjin-Hebei region. As long as a large amount of water vapor is transported into Beijing-Tianjin-Hebei region, once cold air comes, it will form rain or snowfall, not fog! 2）? The destruction of forests in Beijing-Tianjin-Hebei region is also an important reason
From Figure 1, the whole Beijing-Tianjin-Hebei region is also a region lacking forests. Without forests, there is no way to produce a large number of condensation nuclei, and even if the water vapor reaches saturation, it is difficult to form rainfall conditions. ? Turn left | Turn right Figure 2: Even if the humidity reaches nearly 91, it is difficult to rain. If there are enough condensation nuclei, it is easy to rain when the humidity reaches 51 or above. The UAE has achieved the purpose of rainfall when the humidity reaches 31 or above. Why can it rain when the humidity reaches 31 or above? Because water molecules have condensation nuclei, they can reach several times or even up to 6 times the normal condensation! The normal 2 times can easily reach the conditions of rainfall, so 6/2=3, that is, it is possible to rain if it meets one third or the humidity is above 31! See my How Water Molecules Combine for details.
Turn left | Turn right Figure 3: Does the UAE realize artificial rainfall in sunny and dry desert areas? Therefore, it is also very important to restore the forest itself. Try not to let the local humidity reach saturation and not form rain and fog! 3）? The absence of forests in northwest China is one of the important reasons for the rapid arrival of cold air in Beijing, Tianjin and Hebei? Where there is a forest, because the humidity is relatively high, the cold air from the northwest will be partially neutralized by the humidity of the forest, and the cold air will not flow so fast! As shown in the figure:?
Turn left | Turn right
Figure 4: The flow of cold and hot air in Beijing-Tianjin-Hebei region. If areas A, B and C are exposed on the ground (without forests), the temperature in these areas will drop rapidly at night because there is no water vapor regulation, and it will also become the source of cold air. Once the northwest cold air comes to push the cold air in area A, the cold air in area A will push the cold air in area B, and the cold air in area B will push the cold air in area C, The northwest cold air quickly reaches the Beijing-Tianjin-Hebei region to form fog through this domino effect. At the same time, there is no forest in the Beijing-Tianjin-Hebei region and Shandong Peninsula, and the cold air also quickly reaches the Yellow Sea, which further hinders the transportation of ocean airflow to the Beijing-Tianjin-Hebei region to neutralize the cold air and form rainfall. In the absence of sufficient warm and humid airflow, the arrival of cold air can only condense into fog!
Therefore, the root cause of fog in autumn and winter in Beijing, Tianjin and Hebei is that a large number of forests in the third-tier areas (coastal areas, transportation areas and northwest areas) have been destroyed, especially in coastal forest areas!
summary:?
With the pace of cold air going south, the harm of smog gradually goes from north to south, first in the northwest, then in North China, Northeast China, and now in East China, and soon the southwest will catch up with the pace of smog!
The more severely the forest is destroyed, the faster the pace of smog will be. Because of the destruction of the forest, cold air can quickly go south, and the cold air that arrives quickly blocks the ocean airflow from being transported into the inland, which also causes fog in coastal areas. With fog, any industrial area will inevitably suffer from smog! Even places like Shanghai and Hainan, which are at the front end of ocean water vapor transportation, are inevitably harmed by smog! Northbound Guangzhou will suffer from smog, but due to its geographical location, cold air will arrive slowly in Guangzhou! ? 3.? How to solve smog 3.1 in many provinces such as Beijing, Tianjin and Hebei? Eliminating haze is a fundamental short-term measure. When fog comes, we should try our best to eliminate haze, such as shutting down enterprises, restricting cars and banning barbecues. But in the long run, we must transform the pollution sources of these enterprises, achieve the goal of zero emission or upgrade the industrial structure, and build reasonable urban public transportation and green cities.
a .. industrial emissions
This is the biggest pollution source in industrial cities, especially cement, steel and oil refining enterprises. When the fog comes, they must stop production! In the long run, we must transform the pollution sources of these enterprises to achieve the goal of zero emission!
B. Car pollution
This is one of the biggest common pollution sources in any city, especially the dust and floating dust on roads and streets caused by cars during driving, and car exhaust! When the fog comes, except for the necessary public transport vehicles, a large number of cars must be banned! At the same time, it is necessary to absorb dust through tree planting and greening on the two sides of the road, and the three-dimensional greening combined with grass greening below, as well as change the road structure, so as to let mud and sewage be discharged into the grass or sewer on the two sides as far as possible to avoid dust pollution caused by cars! All cars entering the city will be dusted, and the exhaust gas can't enter the city if it doesn't meet the standard! Secondly, the public facilities should be complete to meet the convenience of people's travel! In fact, the subway plus free public bicycles can meet the basic travel needs of the people! Long-distance subway (for long-distance subway, you can build several fast trunk roads (such as north-south subway, east-west subway and ring road), and only stop at subway interchange stations and important stations), and short-distance subway (living and working areas and subway stations) can pass free public bicycles (in order to quickly build free bicycle stations, all citizens can donate one car with one card, and citizens can get bicycles to ride at any free point in the city with one card, and only one car can ride with one card. In most streets of the city, except for short-distance taxis and public transportation (taxis and public transportation are all electric), no other cars are allowed to enter. Except for the main lanes, all the streets in the city have been changed into public lanes and bicycle lanes, and the rest have become green belts! The city can completely establish an environmentally-friendly mode of travel, such as "traffic in the air and cycling in the forest and grassland", subway in the underground, overpass-style driveway in the air (which can be semi-closed or closed and isolated), and the ground is full of forest and grassland green belts and bicycle lanes! ? C. heating and burning coal in cities
This is a big pollution source for heating in northern cities, especially for burning coal! In those days when the fog comes, it is best to try to use other ways to keep warm! It is best to use solar energy to keep warm in the long run! ? D. Cooking by ordinary people and catering enterprises is a huge behavior that is often overlooked and has a particularly large number! When the fog comes, it is best to use electricity and eat less cooking, barbecue and other dining habits that produce smoke! The country should make great efforts to study the architectural design of solar energy and try to make the whole people use solar energy! ? E. urban construction this is a source of urban dust pollution, and reasonable dust prevention measures must be taken in construction! Especially when there is fog, you should stop working! ?
F. Burning garbage and burning crop waste in rural areas is one of the big pollution sources in rural areas and around cities, and it should be banned!
g. Sand blowing and dust flying on the exposed surface
A large number of exposed surfaces (surfaces without forests) are also a pollution source that cannot be ignored! Especially the usual dust enters the polluted roads in the city with the airflow. Once the fog comes, the dust brought by the airflow of the car running is also one of the car pollution! Sprinkle water to solve some road dust in the short term, but most of the exposed surface and long-term solutions must be solved by greening forests. Only forests can prevent and control it three-dimensionally, and forest vegetation can cover the exposed surface!
H. other pollution sources
such as setting off firecrackers and fireworks during the celebration, building decoration, etc., we should formulate the rules for the discharge of pollution sources in the city!
simultaneously? The energy reflected by urban buildings and cement pavements constitutes the "heat island effect", which is also an area that cannot be ignored! ? 3.2? Reduce this carrier "fog" produced by cold air? The method of eliminating fog can also eliminate fog through artificial rainfall in the short term, but the cost is relatively high, and it is only temporary and partial! Long-term or bottom-cutting solutions must be solved by restoring coastal areas, water vapor transportation and inland forests while eliminating haze! ? For example, the Beijing-Tianjin-Hebei region must restore forests in the following areas: 1) The forest in the coastal area of Shandong, it is better for Jiangsu to restore the forest in the coastal area together and transport a large amount of coastal water vapor to the inland, so there will be a large amount of water vapor to rain in the Beijing-Tianjin-Hebei region and the northwest region, and at the same time, because of the arrival of coastal water vapor, it will also slow down the southward movement of cold air, and the generation of natural fog will move northward, and the fog in the Beijing-Tianjin-Hebei region will be reduced! ? 2) Restoration of forests in Beijing-Tianjin-Hebei region