atmosphere (redirected from Planetary atmospheres)

atmosphere /at·mos·phere/ (at´mos-fēr)

1. the entire gaseous envelope surrounding the earth and subject to the earth's gravitational field.

2. the air or climate in a particular place.

3. a unit of pressure, being that exerted by the earth's atmosphere at sea level; equal to 1.01325 × 105pascals (approximately 760 mm Hg). Abbreviated atm.

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at·mos·phere (tm-sfîr)

n.

1. A gas surrounding a given body; a gaseous medium.

2. Abbr. atm, atm. A unit of pressure equal to the air pressure at sea level, approximately equal to 1.01325 × 10⁵ newtons per square meter.

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Atmosphere

A measurement of pressure. One atmosphere equals the pressure of air at sea level (14.7 pounds per square inch [psi]).

Mentioned in: Recompression Treatment

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atmosphere (atm)

[at′məsfir]

Etymology: Gk. atmos, vapor, sphaira, sphere

1 the natural body of air covers the surface of the earth. It is composed of approximately 20% oxygen, 78% nitrogen, and 1% argon and other gases, including small amounts of carbon dioxide hydrogen, and ozone as well as traces of helium, krypton, neon, and xenon and varying amounts of water vapor.

2 an envelope of gas, which may or may not duplicate the natural atmosphere in chemical components.

3 a unit of gas pressure that is usually defined as being equivalent to the average pressure of the earth's atmosphere at sea level, or about 14.7 pounds per square inch or 760 mm Hg. atmospheric, adj.

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atmosphere (atm),

n the natural body of air, composed of approximately 20% oxygen, 78% nitrogen, and 2% carbon dioxide and other gases.