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  2. Density altitude - Wikipedia

    en.wikipedia.org/wiki/Density_altitude

    The density altitude is the altitude relative to standard atmospheric conditions at which the air density would be equal to the indicated air density at the place of observation. In other words, the density altitude is the air density given as a height above mean sea level .

  3. Scale height - Wikipedia

    en.wikipedia.org/wiki/Scale_height

    These figures should be compared with the temperature and density of Earth's atmosphere plotted at NRLMSISE-00, which shows the air density dropping from 1200 g/m 3 at sea level to 0.125 g/m 3 at 70 km, a factor of 9600, indicating an average scale height of 70 / ln(9600) = 7.64 km, consistent with the indicated average air temperature over ...

  4. Standard sea-level conditions - Wikipedia

    en.wikipedia.org/wiki/Standard_sea-level_conditions

    Standard sea-level conditions (SSL), [1] also known as sea-level standard (SLS), defines a set of atmospheric conditions for physical calculations. The term "standard sea level " is used to indicate that values of properties are to be taken to be the same as those standard at sea level, and is done to define values for use in general calculations.

  5. U.S. Standard Atmosphere - Wikipedia

    en.wikipedia.org/wiki/U.S._Standard_Atmosphere

    The other two values (pressure P and density ρ) are computed by simultaneously solving the equations resulting from: the vertical pressure variation, which relates pressure, density and geopotential altitude (using a standard pressure of 101,325 pascals (14.696 psi) at mean sea level as a boundary condition):

  6. International Standard Atmosphere - Wikipedia

    en.wikipedia.org/wiki/International_Standard...

    at each geopotential altitude, where g is the standard acceleration of gravity, and R specific is the specific gas constant for dry air (287.0528J⋅kg −1 ⋅K −1). The solution is given by the barometric formula. Air density must be calculated in order to solve for the pressure, and is used in calculating dynamic pressure for moving vehicles.

  7. Reference atmospheric model - Wikipedia

    en.wikipedia.org/wiki/Reference_atmospheric_model

    Typical usages are as a basis for pressure altimeter calibrations, aircraft performance calculations, aircraft and rocket design, ballistic tables, and meteorological diagrams." [1] For example, the U.S. Standard Atmosphere derives the values for air temperature, pressure, and mass density, as a function of altitude above sea level.

  8. Barometric formula - Wikipedia

    en.wikipedia.org/wiki/Barometric_formula

    = molar mass of Earth's air: 0.0289644 kg/mol; The value of subscript b ranges from 0 to 6 in accordance with each of seven successive layers of the atmosphere shown in the table below. The reference value for ρ b for b = 0 is the defined sea level value, ρ 0 = 1.2250 kg/m 3 or 0.0023768908 slug/ft 3.

  9. Density of air - Wikipedia

    en.wikipedia.org/wiki/Density_of_air

    Air density, like air pressure, decreases with increasing altitude. It also changes with variations in atmospheric pressure, temperature and humidity . At 101.325 kPa (abs) and 20 °C (68 °F), air has a density of approximately 1.204 kg/m 3 (0.0752 lb/cu ft), according to the International Standard Atmosphere (ISA).