Will there be smog in Shanghai tomorrow?

There will be smog in Shanghai tomorrow.

From midnight today to tomorrow morning, low visibility weather will occur in this city. In most areas, there will be thick fog with visibility less than 500 meters, and in some places less than 200 meters. At the same time, the PM2.5 pollution weather process will be superimposed. It is expected that tonight There will be mild to moderate haze by noon tomorrow. As the wind direction turns southerly, the air quality will gradually improve tomorrow afternoon. In addition to fog and haze, weak cold air will also bring cooling. Tomorrow morning will be the coldest morning in recent times. The lowest temperature in the urban area is 2℃, and in the suburbs -3℃ to 0℃, with freezing or thin ice.

In addition, the Shanghai Central Meteorological Observatory issued a yellow fog warning signal at 19:20 on January 3, 2024: Affected by radiation cooling, visibility is expected to be less than 500 in most suburbs of the city from midnight today to tomorrow morning Meters of fog, with visibility less than 200 meters in some areas. Please pay attention to the adverse effects of low visibility on road traffic.

Smog refers to:

Smog, as the name suggests, is fog and haze. But there is a big difference between fog and haze. The aerosol system composed of dust, sulfuric acid, nitric acid and other particulate matter in the air causes visual impairment called haze. Haze is haze (smoke).

Fog is an aerosol system composed of a large number of tiny water droplets or ice crystals suspended in the air near the ground. It mostly appears in autumn and winter (which is also one of the reasons for the widespread haze weather across the country in January 2013). It is the product of water vapor condensation (or sublimation) in the air near the ground. The existence of fog will reduce the transparency of the air and worsen the visibility. If the horizontal visibility of the target object is reduced to less than 1,000 meters, the weather phenomenon of water vapor condensation (or sublimation) suspended in the air near the ground is called fog (Fog) .

If the horizontal visibility of the target is between 1,000 and 10,000 meters, this phenomenon is called light fog or mist. The atmospheric humidity should be saturated when fog is formed (if there are a large number of condensation nuclei, the relative humidity may not necessarily reach 100% before saturation may occur). Because the light scattered by fog composed of liquid water or ice crystals has little relationship with wavelength, the fog looks milky white or bluish white and gray.

The above content refers to Baidu Encyclopedia - Haze