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Flavours of pseudo‐height
Author(s) -
White A. A.,
Beare R. J.
Publication year - 2005
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1256/qj.03.195
Subject(s) - isentropic process , geostrophic wind , atmosphere (unit) , stratification (seeds) , isothermal process , function (biology) , atmospheric pressure , meteorology , mathematics , mechanics , physics , thermodynamics , seed dormancy , germination , botany , evolutionary biology , dormancy , biology
Various functions of pressure have been used as vertical coordinate in atmospheric dynamics. Some of these are called pseudo‐heights , or described as height‐like , although they could equally well be called pseudo‐thicknesses and described as thickness‐like . Three pseudo‐heights are reviewed here, and a unified treatment is presented in which two appear as specializations of the third. The common feature is a standard temperature profile which is a function only of pressure, and the two specializations arise when that function is chosen to represent either an isothermal atmosphere or an isentropic atmosphere. Neither of these choices—or any other reasonable function of pressure—itself introduces approximation. Under quasi‐geostrophic approximation, the need for a non‐zero mean‐state stratification means that a second reference‐temperature profile must be introduced if isentropic pseudo‐height is used as vertical coordinate. © Crown copyright 2005.