8/12/2019 International Standard Atmosphere-1

1/3

International Standard Atmosphere

From Wikipedia, the free encyclopedia

Jump to: navigation, search

Not to be confused with Standard conditions for temperature and pressure.

he International Standard Atmosphere!"S#$ is an atmospheric modelof how thepressure,

temperature, density, and viscosityof the %arth&s atmospherechange over a wide range of altitudes. "t

has been established to provide a common reference for temperature and pressure and consists of

tables of values at various altitudes, plus some formulaeby which those values were derived. he

"nternational 'rgani(ation for Standardi(ation!"S'$ publishes the "S# as an international standard,

"S' )*++:-*./0'ther standards organi(ations, such as the "nternational 1ivil #viation 'rgani(ation

!"1#'$ and the 2nited States 3overnment,publish e4tensions or subsets of the same atmospheric

model under their own standards5making authority.

Contents 6escription

) "1#' Standard #tmosphere

+ 'ther standard atmospheres

7 See also

* 8eferences

9 %4ternal links

Descriptionhe "S# model divides the atmosphere into layers with linear temperature distributions./)0he other

values are computed from basic physical constants and relationships. hus the standard consists of a

table of values at various altitudes, plus some formulasby which those values were derived. For

e4ample, at sea level the standard gives a pressure of +.)*h;a!atm$ and a temperature of *

1elsius, and an initial lapse rateof km !roughly , ft$. he tabulation continues to

km where the pressure has fallen to ))9.+) h;a and the temperature to

8/12/2019 International Standard Atmosphere-1

2/3

"n the above table, geopotential height is calculated from a mathematical model in which the

acceleration due to gravity is assumed constant. 3eometric height results from the !more accurate$

assumption that gravity obeys an inverse sEuare law./citation needed0

he "S# model is based on average conditions at mid latitudes, as determined by "S'&s 1 )>S1 9

technical committee. "t has been revised from time to time since the middle of the )th century.

ICA& Standard Atmosphere

he "nternational 1ivil #viation 'rgani(ation!"1#'$ published their "1#' Standard #tmosphere as

6oc 7BB516 in --+. "t has the same model as the "S#, but e4tends the altitude coverage to B

kilometres !)9),* feet$./*0

he "1#' Standard #tmosphere does not contain water vapour

Some of the values defined by "1#' are:

ICA& Standard Atmosphere

Height km ' t #emperat$re !C %ress$re h%a Lapse ate !C"*** t

km CS@ *. +.)*

8/12/2019 International Standard Atmosphere-1

3/3

he standard conditions for temperature and pressureare a model of gas temperature and pressure used

in chemistry.

http://en.wikipedia.org/wiki/Standard_conditions_for_temperature_and_pressurehttp://en.wikipedia.org/wiki/Chemistryhttp://en.wikipedia.org/wiki/Standard_conditions_for_temperature_and_pressurehttp://en.wikipedia.org/wiki/Chemistry