The difference between fog and haze

1, the difference between fog and haze mainly lies in the size of water content: fog with water content above 90% and haze with water content below 80%. Between 80% and 90%, it is a mixture of fog and haze, but the main component is haze.

In terms of visibility, if the horizontal visibility of the target is reduced to less than 1 km, it is fog; The horizontal visibility is between 1 km and1km, which is called light fog or haze; The horizontal visibility is less than 10 km, which is caused by dust particles, that is, haze or ash haze.

2. Haze is an aggregate of a large number of tiny dust particles, smoke particles or salt particles suspended in the atmosphere, and fog is formed by condensation of water vapor suspended in the atmosphere. When the visibility is lower than 1 km, fog meteorology calls this weather phenomenon fog. It is an aerosol composed of tiny droplets suspended in the atmosphere (the general term for solid particles or droplets suspended in the atmosphere).

3. According to the regulations of the International Meteorological Organization, it is called fog when the visibility drops below 1km, and light fog when the visibility falls between 1 ~ 10km. Haze makes the air turbid, and the horizontal visibility drops below 10km. The droplet diameter is mostly 4-30μm, the number of droplets per unit volume is generally 100- 102/cm3, and the water content is generally less than 0? 1 g/m3. The concentration of droplets in dense fog can reach 500 /cm? 3. The water content reaches 65438±0g/m3.

4. Haze is dust, sulfuric acid, nitric acid, organic hydrocarbons and other particulate matter in the air, which will also make the atmosphere turbid, blur vision and worsen visibility. If the horizontal visibility is less than 10000 meters, the visual distance obstacle caused by this non-aqueous aerosol system is called haze or dust haze. The particles that make up the haze are too small to be distinguished by the naked eye.

Smog is generally milky white, which will weaken the color of objects, making bright objects in the distance appear red and yellow, and dark objects appear red and blue. Due to various reasons, atmospheric condensation nuclei will also form haze when they grow up. Haze is mainly composed of aerosols, which may appear at any time of the day. Fog is an aerosol composed of tiny water droplets suspended in the atmosphere. Fog greatly reduces the horizontal visibility of the ground.

Haze is also called atmospheric brown cloud. In the ground meteorological observation standard of China Meteorological Bureau, the definition of haze weather is: "A large number of extremely fine dry dust particles float evenly in the air, which makes the air with horizontal visibility less than 10 km generally turbid, making bright objects in the distance slightly yellow and red, and making darker objects slightly blue."

Extended data:

In foggy weather, ordinary citizens should do: old people and children should go out less, drive and walk carefully, and pay attention to exercise. Old people and children seldom go out: in moderate and severe smog weather, a large number of aerosol particles harmful to human health accumulate in the air near the ground, which can directly enter and adhere to the upper and lower respiratory tracts and lungs of the human body, causing diseases such as rhinitis and bronchitis, and can also induce lung cancer in this environment for a long time.

Exercise Attention: Moderate and severe smog weather can easily stimulate the human respiratory and circulatory system, especially in the morning when the air quality is poor, people are prone to sprain their bodies during exercise, which may lead to myocardial infarction and pulmonary heart disease. Generally speaking, if there is no cold air activity, rain, snow, strong wind and other weather, it is best to choose the exercise time from morning to evening. The air quality is good, and the amount and intensity of exercise should be moderately reduced in foggy weather.

Dealing with the long-term harm of smog: Long-term persistent smog weather will not only cause current harm to human body, but also cause long-term health harm. Zhong Nanshan reminded that we must be highly alert to the hazards of smog. His preliminary conclusion is that smog pollution will pose a threat to the human respiratory system, cranial nerve system and cardiovascular system, especially lung cancer.

References:

Baidu encyclopedia-haze Baidu encyclopedia-fog