Answer:
Visible brown haze.
Explanation:
Smog is a type of smog produced when ultraviolet light from the sun reacts with nitrogen oxides in the atmosphere.
It is visible as a brown haze, and is most prominent during the morning and afternoon, especially in densely populated, warm cities.
Man-made smog is derived from coal combustion emissions, vehicular emissions, industrial emissions, forest and agricultural fires and photochemical reactions of these emissions.
