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::Atmospheric pressure

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{{#invoke:redirect hatnote|redirect}} Atmospheric pressure is the pressure exerted by the weight of air in the atmosphere of Earth (or that of another planet). In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point. On a given plane, low-pressure areas have less atmospheric mass above their location, whereas high-pressure areas have more atmospheric mass above their location. Likewise, as elevation increases, there is less overlying atmospheric mass, so that atmospheric pressure decreases with increasing elevation. On average, a column of air one square centimeter in cross-section, measured from sea level to the top of the atmosphere, has a mass of about 1.03 kg and weight of about 10.1 N (2.28 lbf). (A column one square inch in cross-section would have a weight of about 14.7 lbs, or about 65.4 N.) Atmospheric pressure is sometimes called barometric pressure.


Atmospheric pressure sections
Intro   Standard atmosphere    Mean sea level pressure    Altitude variation    Local variation    Records    Measurement based on depth of water    Boiling point of water    Measurement and maps    See also    References    External links   

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