Dynamic height

From Glossary of Meteorology

dynamic height

  1. (Also called geodynamic height.) 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. The standard unit of dynamic height is the dynamic meter (or geodynamic 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 height acceleration of gravity is eliminated. In meteorological height calculations geopotential height is more often used than dynamic height. In oceanography, dynamic computations are also based upon units of dynamic height (or dynamic depth).

  2. In oceanography, represents the ability of a column of water to do work due to differences in geopotential (the potential for gravity to do work because of height of the water relative to some reference level).

    The dynamic height is computed from the measured density distribution. Geopotential height differences, expressed by changes in dynamic topography, are a measure of the horizontal pressure gradient force.