What is atmospheric pressure?

  • (noun): The pressure exerted by the atmosphere.
    Synonyms: air pressure

Atmospheric Pressure

Atmospheric pressure is the force per unit area exerted into a surface by the weight of air above that surface 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 mass of air above the measurement point. 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 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). This is approximately the same as having a small car press down on you.

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Some articles on atmospheric pressure:

List Of Mass Spectrometry Acronyms - A
... Appearance potential AP MALDI – Atmospheric pressure matrix-assisted laser desorption/ionization APCI – Atmospheric pressure chemical ...
Climate Of Mars - Atmospheric Properties and Processes - Low Atmospheric Pressure
... mainly of carbon dioxide and has a mean surface pressure of about 600 pascals, much lower than the Earth's 101,000 Pa ... These tides can be significant, being up to 10% of the total atmospheric pressure (typically about 50 Pa) ... effect is less noticeable because of Earth's much greater atmospheric mass ...
Atmospheric Pressure - Boiling Point of Water
... Water boils at about 100 °C (212 °F) at standard atmospheric pressure ... The boiling point is the temperature at which the vapor pressure is equal to the atmospheric pressure around the water ... Because of this, the boiling point of water is lower at lower pressure and higher at higher pressure ...
Climate Of Iceland - Atmospheric Pressure
... There is a persistent area of low pressure near Iceland, aptly named the Icelandic Low, found between Iceland and Greenland ... It is part of a greater pressure system known as the North Atlantic Oscillation ...
Atmosphere Of Venus - Structure and Composition - Troposphere
... top of the troposphere the temperature and pressure reaches Earth-like levels and clouds pick up speed to 100 m/s ... The atmospheric pressure at the surface of Venus is about 92 times that of the Earth, similar to the pressure found 910 metres below the surface of the ocean ... The pressure found on Venus's surface is high enough that the supercritical carbon dioxide is technically no longer a gas, but a supercritical fluid ...

Famous quotes containing the words pressure and/or atmospheric:

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