What are the natural causes of cloudy weather?

I don't know if you have noticed that in winter, the surface of the city where you live often has the same weather as clouds and fog, and the sky is gray from morning till night, which is smog weather. Meteorology, a large number of tiny dust particles, smoke particles or salt particles suspended in the atmosphere make the air turbid, and the horizontal visibility drops below 10km, which is called cloudy weather. The reason for this kind of weather is that when the atmospheric circulation is relatively stable, the atmospheric stratification is stable, and the airflow (wind speed) near the ground layer is very small, and the atmosphere will form an "inversion layer" with warm upper and cold lower. In addition, the air humidity near the ground layer is high, and various pollutants accumulate, resulting in cloudy weather. Haze and fog seem similar, but in fact they are different. Fog is water vapor close to the ground, which floats in the air after being condensed by cold. Haze is a thin "grey curtain" formed by excessive accumulation of tiny inhalable particles in the air. Due to cloudy weather conditions, there are more smog and pollutants in the air, which is not conducive to the health of patients with chronic bronchitis and asthma. After staying in this air for a certain period of time, the symptoms of patients with heart disease and lung disease will be obviously aggravated, and healthy people will also feel unwell. In addition, when cloudy days appear, it is easy to make people feel depressed and depressed because of insufficient light, and even induce depression. So how do we deal with smog? First of all, we should pay attention to the change of the weather. Once there is cloudy weather, you should try to reduce going out, and don't do sports in this weather. Drink plenty of water, sprinkle some water on the cement floor properly to suppress dust; Patients with heart disease and respiratory diseases should reduce physical exertion and do less outdoor activities; Pay attention to emotional adjustment. When the light is too dim, try to turn on the light to listen to music, control depression and boredom as much as possible, and prevent the occurrence of diseases.