CLOUD CEILING Meaning and
Definition
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Cloud ceiling refers to the measurement of the lowest level in the atmosphere where the visibility of objects or the sky is obscured by clouds. It is a term primarily used in meteorology and aviation to describe the height or altitude above the ground that separates cloud cover from visually clear air. The cloud ceiling is typically determined by measuring the height of the lowest cloud base or by using instruments such as ceilometers, which employ laser beams to detect the presence and altitude of cloud layers.
Cloud ceilings greatly influence weather conditions and air travel, as they can affect visibility and the ability of aircraft to navigate safely. Aviation regulations require pilots to be aware of the cloud ceiling in order to determine the appropriate altitude for takeoff, landing, and flight, as well as to establish minimum visibility requirements. Airports often report the cloud ceiling in their weather observations to assist pilots in making informed decisions.
The cloud ceiling is usually described in terms of elevation above ground level (AGL), which represents the distance between the bottom of the clouds and the Earth's surface. It can range from a few hundred feet to several thousand feet above the ground. Cloud ceilings are categorized into different levels, such as few, scattered, broken, or overcast, depending on the density and coverage of clouds. The term "cloud base" is sometimes used interchangeably with cloud ceiling, although it specifically refers to the lowest part of a cloud layer rather than the altitude at which visibility is restricted.
Etymology of CLOUD CEILING
The term "cloud ceiling" originated from the combination of two words: "cloud" and "ceiling".
The word "cloud" derives from the Old English word "clūd", which meant "a mass of rock" or "a hill". Over time, its meaning transformed to describe the visible mass of vapor suspended in the air. The Old English word "clūd" is related to the Old High German word "klōt", meaning "a mass" or "a ball".
The word "ceiling" comes from the Middle English word "sīeling", which referred to the interior part of a roof or the upper limit of a room. It originates from the Latin word "caelum", meaning "sky" or "heaven".
