Atmospheric scale height¶
The atmospheric scale height, H, characterizes the extent of the atmosphere. It is defined as
where \(k_B\) is the Boltzmann constant, T is the atmospheric temperature, \(\mu\) is the mean
molecular weight, \(m_u\) is the unified atomic mass unit and g is the gravitational
acceleration. PyAstronomy provides a function accepting SI units (atmosphericScaleHeight()
) and an alternative accepting
Earth or Jovian units atmosphericScaleHeight_MR()
). Required conversion constants are adopted from PyA’s
constants package.
Example:¶
from PyAstronomy import pyasl
T, mu, g = 290, 28.97, 9.8
she = pyasl.atmosphericScaleHeight(T, mu, g)
print("Earth")
print(f"T, mu, g = {T} K, {mu}, {g} m/s**2")
print(f"Scale height = {she:4.1f} [km]")
T, mu, mp, rp = 165, 2.2, 1, 1
shj = pyasl.atmosphericScaleHeight_MR(T, mu, mp, rp, "J")
print("Jupiter")
print(f"T, mu, mp, rp = {T} K, {mu}, {mp} [MJ], {rp} [RJ]")
print(f"Scale height = {shj:4.1f} [km]")
API documentation¶
- PyAstronomy.pyasl.atmosphericScaleHeight(T, mu, g)¶
Atmospheric scale height
- Parameters
- Tfloat
Temperature in K
- mufloat
Mean olecular weight
- gfloat
Gravitational acceleration [m/s**2]
- Returns
- Scale heightfloat
Atmospheric scale height in km
- PyAstronomy.pyasl.atmosphericScaleHeight_MR(T, mu, Mp, Rp, ref)¶
Atmospheric scale height
- Parameters
- Tfloat
Temperature in K
- mufloat
Mean olecular weight
- Mpfloat
Mass of planet [wrt Jupiter or Earth (see ref)]
- Rpfloat
Radius of planet [wrt Jupiter or Earth (see ref)]
- refstring, {J, E}
Determines whether Mp and Rp are considered in units of the Earth (E) or Jupiter (J)
- Returns
- Scale heightfloat
Atmospheric scale height in km