flipchem.msis

class flipchem.msis.MSIS(date)[source]

A python wrapper to the NRLMSISE-00 C library version of the code written by Dominik Brodowski, which is based on the original Fortran version of the model. See [4].

Parameters:

date (datetime.datetime) – Date and time for which to evaluate MSIS.
Variables:
  • f107 (float) – The F10.7 solar flux for the previous day.
  • f107a (float) – The 81 day average F10.7 solar flux.
  • ap (array_like) – An array of AP index values. See read_geophys().

Notes

This code automatically grabs the f10.7, f10.7a, and AP, are required to run MSIS, from a local cache. See read_geophys() for more details.

Examples

from flipchem import MSIS
from datetime import datetime

date = datetime(2017,1,4,2)
alt = 100
glat = 60
glon = -70

msis = MSIS(date)
outputs = msis.get_point(glat,glon,alt)
H,He,N,O,N2,O2,Ar,Mass,AnomO,Texo,Tn = outputs

References

[4]Picone, J. M., Hedin, A. E., Drob, D. P., and Aikin, A. C. (2002). NRLMSISE‐00 empirical model of the atmosphere: Statistical comparisons and scientific issues, J. Geophys. Res., 107(A12), 1468, doi:10.1029/2002JA009430.
get_point(glat, glon, alt)[source]

Evaluates the flipchem model for the input geodetic coordinates

Parameters:
  • glat (float) – Geodetic Latitude
  • glon (float) – Geodetic Longitude
  • alt (float) – Altitude above the Geodetic surface of the Earth
Returns:

  • H (float) – Hydrogen number density in number per cubic meter
  • He (float) – Helium number density in number per cubic meter
  • N (float) – Nitrogen number density in number per cubic meter
  • O (float) – Atomic Oxygen number density in number per cubic meter
  • N2 (float) – Diatomic Nitrogen number density in number per cubic meter
  • O2 (float) – Diatomic Oxygen number density in number per cubic meter
  • Ar (float) – Argon number density in number per cubic meter
  • Mass (float) – Total mass in kilograms
  • AnomO (float) – Anomlous Oxygen number density in number per cubic meter
  • Texo (float) – Exosphere temperature in Kelvin
  • Tn (float) – Mean neutral temperature in Kelvin
flipchem.msis.compute_electron_neutral_collfreq(densities, Te)[source]

This code calculates the elastic electron-neutral collision frequencies following Chapter 4 of [3].

Parameters:
  • densities (array_like) – An array of neutral densities in this order: H, He, N, O, N2, O2 with units of number per cubic meter. See Notes for comment about Nitrogen.
  • Te (float) – The electron temperature in Kelvin
Returns:

nu_en (float) – The the total electron-neutral collision frequency summed over the collisions between electrons and H, He, O, N2, O2.

Notes

The current code DOES NOT include an electron-Nitrogen collision frequency.

References

[3]Schunk, R., & Nagy, A. (2000). Ionospheres: Physics, Plasma Physics, and Chemistry (Cambridge Atmospheric and Space Science Series). Cambridge: Cambridge University Press. 99-054707 ISBN: 0 521 60770 1
flipchem.msis.compute_ion_neutral_collfreq(densities, Tn, mi, Ti=None)[source]

This code calculates the elastic and resonant ion-neutral collision frequencies following Chapter 4 of [1]. Uses Argon and Helium from [2].

Parameters:
  • densities (array_like) – An array of neutral densities in this order: H, He, N, O, N2, O2, Ar with units of number per cubic meter.
  • Tn (float) – The mean neutral temperature in Kelvin
  • mi (integer) – The ion mass in amu
  • Ti (float, optional) – The ion temperature in Kelvin
Returns:

nu_in (float) – The the total ion-neutral collision frequency summed over the collisions between the input ion and H, He, N, O, N2, O2, Ar

References

[1]Schunk, R., & Nagy, A. (2000). Ionospheres: Physics, Plasma Physics, and Chemistry (Cambridge Atmospheric and Space Science Series). Cambridge: Cambridge University Press. 99-054707 ISBN: 0 521 60770 1
[2]Gaiser C, Fellmuth B. Polarizability of Helium, Neon, and Argon: New Perspectives for Gas Metrology. Phys Rev Lett. 2018 Mar 23; 120(12):123203. doi: 10.1103/PhysRevLett.120.123203.