List of symbols

Symbol	Name of the symbol	Unit
$H$	geopotential altitude	$\mathrm{m}$
$H_b$	lower limit geopotential altitude	$\mathrm{m}$
$H_p$	pressure scale height	$\mathrm{m}$
$M$	air molar mass at sea level	$\mathrm{kg\cdot kmol^{-1}}$
$N_A$	Avogadro constant	$\mathrm{kmol^{-1}}$
$R$	specific gas constant	$\mathrm{J\cdot K^{-1}\cdot kg^{-1}}$
$R^*$	universal gas constant	$\mathrm{J\cdot K^{-1}\cdot kmol^{-1}}$
$S$	Sutherland's empirical coefficients $ S $	$\mathrm{K}$
$T$	temperature $ T $	$\mathrm{K}$
$T_b$	lower limit temperature	$\mathrm{K}$
$a$	speed of Sound	$\mathrm{m/s}$
$g$	gravitational acceleration	$\mathrm{m/s^2}$
$h$	height above sea level	$\mathrm{m}$
$l$	mean free path of air particles	$\mathrm{m}$
$n$	air number density	$\mathrm{m^{-3}}$
$p_b$	lower limit pressure	$\mathrm{Pa}$
$p_{air}$	atmospheric pressure air	$\mathrm{Pa}$
$r$	nominal earth's radius	$\mathrm{m}$
$v̄$	mean air-particle speed	$\mathrm{m/s}$
$β$	temperature gradient $ β $	$\mathrm{K\cdot m^{-1}}$
$β_s$	Sutherland's empirical coefficients $ β_s $	$\mathrm{kg\cdot m^{-1}\cdot s^{-1}\cdot K^{-1/2}}$
$γ_{air}$	specific weight air	$\mathrm{kg\cdot m^{-2}\cdot s^{-2}}$
$κ$	adiabatic index	$\mathrm{ }$
$λ$	thermal conductivity	$\mathrm{W\cdot m^{-1}\cdot K^{-1}}$
$μ$	dynamic viscosity	$\mathrm{kg\cdot m^{-1}\cdot s^{-1}}$
$ν$	kinematic viscosity	$\mathrm{m^2\cdot s^{-1}}$
$ρ_{air}$	density air	$\mathrm{kg/m^3}$
$σ$	effective collision diameter of an air molecule	$\mathrm{m}$
$φ$	latitude	$\mathrm{°}$
$ω$	air-particle collision frequency	$\mathrm{Hz}$