An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

Distance upward from a given level to a fixed point.

M.E., from O.E. hiehthu; → high + -th a suffix forming nouns of action (e.g., birth) or abstract nouns denoting quality or condition (depth; length; warmth).

Bolandi, bolandâ "height," noun forms from boland "high," variants bâlâ "up, above, high, elevated, height," borz "height, magnitude" (it occurs also in the name of the mountain chain Alborz), Lori dialect berg "hill, mountain;" Mid.Pers. buland "high;" O.Pers. baršan- "height;" Av. barəz- "high, mount," barezan- "height;" cf. Skt. bhrant- "high;" L. fortis "strong" (Fr. & E. force); O.E. burg, burh "castle, fortified place," from P.Gmc. *burgs "fortress;" Ger. Burg "castle," Goth. baurgs "city," E. burg, borough, Fr. bourgeois, bourgeoisie, faubourg); PIE base *bhergh- "high."
Farâzâ, noun of farâz "above, up, upon, on the top, aloft," from Mid.Pers. farâz, farâc "forward, prominent, distinguished;" Av. frānk- (adj.) "turned toward the front," fraca (adv.) "forward, forth," fraš (adv.) "forward, forth; before;" Proto-Iranian *frānk-.

A basic ingredient of the → mixing length theory that scales with the → mixing length. It is defined by the relation: H_P = -dr/dln P = -Pdr/dP , where r is the height and P the pressure. See also → scale height.

→ pressure; → scale; → height.

The height within which some parameter, such as pressure or density, decreases by a factor of e. For example, an atmospheric scale height of 100 km means that the value at 100 km is 1/e the value at the surface.

→ scale; → height.