NationMaster - Encyclopedia: International Standard Atmosphere

The International Standard Atmosphere (ISA) is a model of the standard variation of pressure, temperature, density, and viscosity with altitude in the Earth's atmosphere. It is based on average conditions at mid latitudes, as determined by the International Civil Aviation Organization (ICAO). The atmosphere is divided into layers with assumed temperature distributions, and the other values are computed from basic physical constants and relationships. The use of water pressure - the Captain Cook Memorial Jet in Lake Burley Griffin, Canberra. ... Fig. ... In physics, density is defined as mass m per unit volume V. For the common case of a homogeneous substance, it is expressed as: where, in SI units: Ï (rho) is the density of the substance, measured in kgÂ·m-3 m is the mass of the substance, measured in kg... The related Category:Units of viscosity has been nominated for deletion, merging, or renaming. ... Altitude is the elevation of an object from a known level or datum. ... Layers of Atmosphere - not to scale (NOAA)[2] Earths atmosphere is a layer of gases surrounding the planet Earth and retained by the Earths gravity. ... The International Civil Aviation Organization (ICAO), an agency of the United Nations, codifies the principles and techniques of international air navigation and fosters the planning and development of international air transport to ensure safe and orderly growth. ...

Various tabulations of the 1976 standard may be found on the web, e.g. at [1], or, of an earlier but similar standard, in publications such as Appendix 1 of Batchelor. The latter tabulation gives at sea level a pressure of 1.013 bar and a temperature of 15 C, and an initial lapse rate of 6.5 C/km. Above 12km the tabulated temperature is essentially constant. The tabulation continues to 18km where the pressure has fallen to 0.075 bar and the temperature to -56.5 C. The lapse rate is the rate at which an atmospheric variable (usually temperature) decreases with altitude. ...

1 Layers in the ISA
2 See also
3 References
4 External link

Layers in the ISA

Standard Atmosphere 1976
Layer	Level Name	Base Geopotential Height h (in km)	Base Geometric Height z (in km)	Lapse Rate (in °C/km)	Base Temperature T (in °C)	Base Atmospheric Pressure p (in kPa)
0	Troposphere	0.0	0.0	-6.5	+15.0	101,325
1	Tropopause	11.000	11.019	+0.0	-56.5	22,632
2	Stratosphere	20.000	20.063	+1.0	-56.5	5,474.9
3	Stratosphere	32.000	32.162	+2.8	-44.5	868.02
4	Stratopause	47.000	47.350	+0.0	-2.5	110.91
5	Mesosphere	51.000	51.413	-2.8	-2.5	66.939
6	Mesosphere	71.000	71.802	-2.0	-58.5	3.9564
7	Mesopause	84.852	86.000	—	-86.2	0.3734

Atmosphere diagram showing the mesosphere and other layers. ... The tropopause is a boundary region in the atmosphere between the troposphere and the stratosphere. ... Atmosphere diagram showing stratosphere. ... Atmosphere diagram showing stratosphere. ... The stratopause is the level of the atmosphere which is the boundary between the stratosphere and the mesosphere. ... The mesosphere (from the Greek words mesos = middle and sphaira = ball) is the layer of the Earths atmosphere that is directly above the stratosphere and directly below the thermosphere. ... The mesosphere (from the Greek words mesos = middle and sphaira = ball) is the layer of the Earths atmosphere that is directly above the stratosphere and directly below the thermosphere. ... The mesosphere (from the Greek words mesos = middle and sfaira = ball) is the layer of the Earths atmosphere that is directly above the stratosphere and directly below the thermosphere. ...

References

Batchelor, G. K., An Introduction to Fluid Dynamics, Cambridge Univ. Press, 1967.
Tabulation of 1976 standard at University of Sydney aeronautical mechanics site
ICAO, Manual of the ICAO Standard Atmosphere (extended to 80 kilometres (262 500 feet)), Doc 7488-CD, Third Edition, 1993, ISBN 92-9194-004-6.

External link

ICAO

Categories: Atmospheric thermodynamics | Aviation terminology | Atmospheric science stubs

Results from FactBites:

Atmospheric pressure Summary (2330 words)
	Standard atmospheric pressure or "the standard atmosphere" (1 atm) is defined as 101.325 kilopascals (kPa) or 760 mmHg.
	Atmospheric pressure is often measured with a mercury barometer, and a height of approximately 760 mm (30 inches) of mercury is often used to teach, make visible, and illustrate (and measure) atmospheric pressure.
	International Standard Atmosphere - a tabulation of typical variation of principal thermodynamic variables of the atmosphere (pressure, density, temperature etc) with altitude, at mid latitudes.

Qwika - similar:Bar_(unit) (1836 words)
	When expressed as a measurement, an atmosphere (symbol: atm) or standard atmosphere is a unit of pressure roughly equal to the average atmospheric pressure at sea level on Earth.
	It is absolutely necessary to define the standard reference conditions of temperature and pressure when expressing a gas volume or a volumetric flow rate because the volume of a gas varies with the temperature and pressure of the gas.
	Earth's atmosphere is a layer of gases surrounding the planet Earth and retained by the Earth's gravity.

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Contents

Layers in the ISA GA_googleFillSlot("encyclopedia_square");

See also

References

External link

Layers in the ISA