DENSITY ALTITUDE

Density altitude is the altitude in the International Standard Atmosphere at which the air density would be equal to the actual air density at the place of observation. "Density Altitude" is the pressure altitude adjusted for non-standard temperature.Both increase in temperature and increase in humidity cause a reduction in air density. Thus in hot and humid conditions the density altitude at a particular location may be significantly higher than the geometric altitude.
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An atmospheric density expressed in terms of the altitude which corresponds with that density in the standard atmosphere. 1/3/73

Densité atmosphérique exprimée en altitude correspondant à cette densité dans l'atmosphère standard. 1/3/73