pyrfu.mms.eis_moments module#

pyrfu.mms.eis_moments.eis_moments(inp, specie: str = 'proton', n_bg: DataArray | None = None, p_bg: DataArray | None = None)[source]#

Computes the partial moments given the omni-directional differential particle flux and the ion specie under the assumption of angular isotropy and non-relativistic ions using the formula from [1]

\[ \begin{align}\begin{aligned}\begin{split}n \\left [ m^{-3} \\right ] = 4 \\pi \\sqrt{\\frac{m_i}{2}} \\sum_{i} \\left ( E_i^{1/2} \\right)^0 \\left ( \\frac{J_i}{E_i}\\right) \\left ( E_i^{1/2} \\textrm{d} E_i\\right)\end{split}\\\begin{split}P \\left [ Pa \\right ] = 4 \\pi \\sqrt{\\frac{m_i}{2}} \\sum_{i} \\left ( E_i^{1/2} \\right)^2 \\left ( \\frac{J_i}{E_i}\\right) \\left ( E_i^{1/2} \\textrm{d} E_i\\right)\end{split}\\\begin{split}T \\left [ K \\right ] = \\frac{P}{n k_b}\end{split}\end{aligned}\end{align} \]
Parameters:

  • inp (xarray.DataArray) – Omni-directional differential particle flux.

  • specie ({"proton", "alpha", "oxygen"}, Optional) – Particle specie. Default is “proton”.

  • n_bg (xarray.DataArray, Optional) – Time series of the background density. If None do not remove penetrating radiations.

  • p_bg (xarray.DataArray, Optional) – Time series of the background pressure. If None do not remove the penetrating radiations.

Returns:

  • n (xarray.DataArray) – Time series of the number density in [cm^{-3}]

  • p (xarray.DataArray) – Time series of the pressure in [nPa]

  • t (xarray.DataArray) – Time series of the temperature in [eV]

Notes

The input omni-directional differential particle flux must be given in [(1/cm^2 s sr keV)^{-1}], and the energy must be in [keV]. The integration is performed using the composite Simpson’s rule.

References

[1]

Mauk, B. H., D. G. Mitchell, R. W. McEntire, C. P. Paranicas, E. C. Roelof, D. J. Williams, S. M. Krimigis, and A. Lagg (2004), Energetic ion characteristics and neutral gas interactions in Jupiter’s magnetosphere, J. Geophys. Res., 109, A09S12, doi:10.1029/2003JA010270.