What are the icons of fog and frost in weather forecasts?

As can be seen from the picture:

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 is the condensation (or condensation) of water vapor in the air near the ground. product of China). 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) ; The phenomenon in which the horizontal visibility of the target is between 1,000 and 10,000 meters 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.

Haze, also known as haze (haze), dust, sulfuric acid, nitric acid, organic hydrocarbons and other particles in the air can also make the atmosphere turbid, blur the vision and cause visibility to deteriorate. If the horizontal visibility is less than 10,000 meters At that time, the visual range obstruction caused by this non-aqueous aerosol system was called haze or dust-haze, and the Hong Kong Observatory called it haze.

Extended information:

Smog is sweeping across the country. In foggy weather, the air circulation is poor and the air quality is also poor. For children, who have poor physical resistance, the haze is The impact of weather on young children is greater than that of adults. The haze weather phenomenon will have significant negative impacts on climate, environment, health, economy, etc., such as causing acid rain and photochemical smog in urban atmosphere, resulting in reduced atmospheric visibility and obstructing air and water surfaces. and land transportation; increase mortality, aggravate chronic diseases, worsen respiratory and cardiac diseases, change lung function and structure, affect reproductive capacity, change the body's immune structure, etc.

In haze weather, a large number of dust particles, smoke particles and other harmful substances floating in the air will cause harm to the human respiratory tract. A large number of particles, dust, pollutant viruses, etc. floating in the air, once inhaled by the human body, It will irritate and destroy the respiratory mucosa, dry the nasal cavity, destroy the defense ability of the respiratory mucosa, and allow bacteria to enter the respiratory tract, easily causing upper respiratory tract infection.

Reference material: Weather legend - China Weather Network?