Dynamic Height
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Dynamic Height
</dt>
The height of a point in the atmosphere
expressed in a unit proportional to the geopotential
at that point. Since the geopotential at altitude z is numerically
equal to the work done when a particle of unit mass is lifted from sea level
up to this height, the dimensions of dynamic height are those of potential
energy per unit mass. Also called geodynamic height.
</dd>
The standard unit of dynamic height H_{d} is the dynamic meter
(or geodynamic meter), defined as 10 meters per second squared; it is related
to the geopotential Missing Image:img src="SP7-d_files/phisms.gif", the geometric height z in
meters, and the geopotential height Z in geopotential meters by
squared. (Some sources prefer to give the constants 10 and 9.8 the units of meters per second squared so that the units of Missing Image:img src="SP7-d_files/phisms.gif" and Z would be the same as those of the geometric height.) The dynamic meter is about 2 percent longer than the geometric meter and the geopotential meter. One of the practical advantages of the dynamic height over the geometric height is that when the former is introduced into the hydrostatic equation the variable acceleration of gravity is eliminated. In meteorological height calculations, geopotential height is more often used than dynamic height. </dd>
References
This article is based on NASA's Dictionary of Technical Terms for Aerospace Use