Fog is a visible aerosol consisting of tiny water droplets or ice crystals suspended in the air at or near the Earth's surface.
Xem thêmFog can be considered a type of low-lying cloud, usually resembling stratus.
Xem thêmIn turn, fog has affected many human activities, such as shipping, travel, and warfare.
Xem thêmThe term "fog" is typically distinguished from the more generic term "cloud" in that fog is low-lying, and the moisture in the fog is often generated locally.
Xem thêmBy definition, fog reduces visibility to less than 1 kilometre (0.62 mi), whereas mist causes lesser impairment of visibility.
Xem thêmFog forms when the difference between air temperature and dew point is less than 2.5 °C (4.5 °F).
Xem thêmFog begins to form when water vapor condenses into tiny liquid water droplets that are suspended in the air.
Xem thêmFog, like its elevated cousin stratus, is a stable cloud deck which tends to form when a cool, stable air mass is trapped underneath a warm air mass.
Xem thêmFog normally occurs at a relative humidity near 100%.
Xem thêmHowever, fog can form at lower humidities, and can sometimes fail to form with relative humidity at 100%.
Xem thêmFog commonly produces precipitation in the form of drizzle or very light snow.
Xem thêmDrizzle occurs when the humidity of fog attains 100% and the minute cloud droplets begin to coalesce into larger droplets.
Xem thêmThis can occur when the fog layer is lifted and cooled sufficiently, or when it is forcibly compressed from above by descending air.
Xem thêmThe thickness of a fog layer is largely determined by the altitude of the inversion boundary, which in coastal or oceanic locales is also the top of the marine layer, above which the air mass is warmer and drier.
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