lir_achem.compute_ionisation

Here is computed the ionisation rate from the absorbed solar flux

Functions

compute_photon_flux(rad_here[, HXR_bins])

Here we just convert the solar flux (in W/m^2) to the photon flux (particle/m^2/s)

conversion_OpNp(rad_here, n_here)

Computes the fraction of O+ and N+ converted into NO+ We suppose that O+ is created into its ground state (which is a simplification) and that O+ and N+ do not interact with other species EXCEPT to be converted into either O2+ or NO+.

ion_N2_to_N2p(Phi_SXR, Phi_HXR, rad_here, n_here)

Computes the ionisation of N2 (in cm-3/s-1) to give N2+.

ion_N2_to_Np(Phi_SXR, Phi_HXR, rad_here, n_here)

Computes the ionisation of N2 (in cm-3/s-1) to give N+.

ion_NO_to_NOp(Phi_EUV, rad_here, n_here[, ...])

Computes the ionisation of NO (in cm-3/s-1) to give NO+.

ion_NOp_from_XR(Phi_SXR, Phi_HXR, rad_here, ...)

Computes the creation of NO+ with resutls from the ionisation of O+, N+ converted into NO+

ion_O2_to_O2p(Phi_SXR, Phi_HXR, rad_here, n_here)

Computes the ionisation of O2 (in cm-3/s-1) to give O2+.

ion_O2_to_Op(Phi_SXR, Phi_HXR, rad_here, n_here)

Computes the ionisation of O2 or O (in cm-3/s-1) to give O+.

ion_from_cosmicrays(n_here, rad_here)

Computes the ionisation of O2 by cosmic rays.

ionisation_O2_from_O21Dg(rad_here, n_here)

Computes the ionisation of O2(1Dg) from UV radiation As an approximation, following Crutzen et al., 1970 (Figure 1), we will take [O_2 (1Dg)] = 1e10 cm-3 in the atmopshere

ionisation_O2_from_XR(Phi_SXR, Phi_HXR, ...)

Computes the ionisation of O2 with resutls from the ionisation of O+, N+ and N2+ then converted into O2+ At first approximation, all N2+ are converted to O2+ (Rowe, 1974, Mitra, 1974) The XR also create O+ and N+, which are converted into NO+ and O2+
lir_achem.compute_ionisation.ion_from_cosmicrays(n_here, rad_here)[source]

Computes the ionisation of O2 by cosmic rays. We use the approximation described in Lehtinen et al., 2007. We will suppose that CR produce both O2+ and e-

Parameters:

  • n_here – Neutrals class instance

  • rad_here – Radiation class instance

lir_achem.compute_ionisation.ion_N2_to_N2p(Phi_SXR, Phi_HXR, rad_here, n_here, sigma_SXR_N2p=5.019e-22, sigma_HXR_N2p=5.115e-23, HXR_bins=True)[source]

Computes the ionisation of N2 (in cm-3/s-1) to give N2+. The ionisation cross section come from Table 3 of Pavlov, 2014 and its erratum If HXR_bin, the cross-sections for HXR come from Siskind et al., 2022 and are multiplied by the branching factors in Solomon & Qian, 2005. pe/pi is taken from Siskind et al., 2022 Following Nicolet & Aikin, 1960 and the results from Bourdeau et al., 1966, each ionisation by X-ray is multiplied by the number of created ion pair, which is 45 for SXR and 165 for HXR

Parameters:

  • Phi_HXR (Phi_SXR,) – Absorbed SXR and HXR fluxes

  • rad_here – Radiation class instance

  • n_here – Neutrals class instance

  • sigma_SXR_N2p – Ionisation cross-section of N2 to give N2+ in cm^2 due to SXR (Default: 5.019e-22 cm^2)

  • sigma_HXR_N2p – Ionisation cross-section of N2 to give N2+ in cm^2 due to HXR (Default: 5.115e-23 cm^2)

  • HXR_bins – Bollean, Default=True. If True, the ionisation will be computed using the bins in rad_here. If False, it will only use the average GOES HXR flux.

Returns:

Ionisation rate (in part/cm^3 /s) in the D-region altitudes (given by the altitudes_D in rad_here)

lir_achem.compute_ionisation.ion_N2_to_Np(Phi_SXR, Phi_HXR, rad_here, n_here, sigma_SXR_Np=2.32e-20, sigma_HXR_Np=2.351e-21, HXR_bins=True)[source]

Computes the ionisation of N2 (in cm-3/s-1) to give N+. The ionisation cross section come from Table 3 of Pavlov, 2014 and its erratum Following Nicolet & Aikin, 1960 and the results from Bourdeau et al., 1966, each ionisation by X-ray is multiplied by the number of created ion pair, which is 45 for SXR and 165 for HXR

Parameters:

  • Phi_HXR (Phi_SXR,) – Absorbed SXR and HXR fluxes

  • rad_here – Radiation class instance

  • n_here – Neutrals class instance

  • sigma_SXR_Np – Ionisation cross-section of N2 to give N+ in cm^2 due to SXR (Default: 2.320e-20 cm^2)

  • sigma_HXR_Np – Ionisation cross-section of N2 to give N+ in cm^2 due to HXR (Default: 2.351e-21 cm^2)

  • HXR_bins – Bollean, Default=True. If True, the ionisation will be computed using the bins in rad_here. If False, it will only use the average GOES HXR flux. If it is True, the ionisation of N2 to N+ is put to 0

Returns:

Ionisation rate (in part/cm^3 /s) in the D-region altitudes (given by the altitudes_D in rad_here)

lir_achem.compute_ionisation.ion_O2_to_Op(Phi_SXR, Phi_HXR, rad_here, n_here, sigma_HXR_Op=2.436e-21, sigma_SXR_Op=2.89e-20, HXR_bins=True)[source]

Computes the ionisation of O2 or O (in cm-3/s-1) to give O+. The ionisation cross section come from Table 3 of Pavlov, 2014 Following Nicolet & Aikin, 1960 and the results from Bourdeau et al., 1966, each ionisation by X-ray is multiplied by the number of created ion pair, which is 45 for SXR and 165 for HXR NOTE: for the first HXR bin, Siskind et al., do not indicated pe/pi. We take the average value in Solomon & Qian, 2005 instead. We also do not discriminate between the different excited states of O+ If HXR_bin, the cross-sections for HXR come from Siskind et al., 2022 and are multiplied by the branching factors in Solomon & Qian, 2005. pe/pi is taken from Siskind et al., 2022 NOTE: The Branching ratio for the ionisation of O2+ is 0 in Solomon & Qian, 2005, but it was underestimated (see Pavlov, 2014). Instead, we recompute it from Table 3 of Pavlov, 2014 and Table A2 of Solomon & Qian, 2005. This gives beta=0.011 for O2 -> 02+, SO beta=0.989 for O2 -> 2O+

Parameters:

  • Phi_HXR (Phi_SXR,) – Absorbed SXR and HXR fluxes

  • rad_here – Radiation class instance

  • n_here – Neutrals class instance

  • sigma_SXR_Op – Ionisation cross-section of O2 to give O+ in cm^2 due to SXR (Default: 2.890e-20 cm^2)

  • sigma_HXR_Op – Ionisation cross-section of O2 to give O+ in cm^2 due to HXR (Default: 2.436e-21 cm^2)

  • HXR_bins – Bollean, Default=True. If True, the ionisation will be computed using the bins in rad_here. If False, it will only use the average GOES HXR flux.

Returns:

Ionisation rate (in part/cm^3 /s) in the D-region altitudes (given by the altitudes_D in rad_here)

lir_achem.compute_ionisation.ion_O2_to_O2p(Phi_SXR, Phi_HXR, rad_here, n_here, sigma_HXR_O2p=2.625e-23, sigma_SXR_O2p=3.174e-22, HXR_bins=True)[source]

Computes the ionisation of O2 (in cm-3/s-1) to give O2+. The ionisation cross section come from Table 3 of Pavlov, 2014 Following Nicolet & Aikin, 1960 and the results from Bourdeau et al., 1966, each ionisation by X-ray is multiplied by the number of created ion pair, which is 45 for SXR and 165 for HXR If HXR_bin, the cross-sections for HXR come from Siskind et al., 2022 and are multiplied by the branching factors in Solomon & Qian, 2005. pe/pi is taken from Siskind et al., 2022 NOTE: The Branching ratio for the ionisation of O2+ is 0 in Solomon & Qian, 2005, but it was underestimated (see Pavlov, 2014). Instead, we recompute it from Table 3 of Pavlov, 2014 and Table A2 of Solomon & Qian, 2005. This gives beta=0.011

Parameters:

  • Phi_HXR (Phi_SXR,) – Absorbed SXR and HXR fluxes

  • rad_here – Radiation class instance

  • n_here – Neutrals class instance

  • sigma_SXR_O2p – Ionisation cross-section of O2 to give O+ in cm^2 due to SXR (Default: 2.625e-23 cm^2)

  • sigma_HXR_O2p – Ionisation cross-section of O2 to give O+ in cm^2 due to HXR (Default: 3.174e-22 cm^2)

  • HXR_bins – Boolean, Default=True. If True, the ionisation will be computed using the bins in rad_here. If False, it will only use the average GOES HXR flux.

Returns:

Ionisation rate (in part/cm^3 /s) in the D-region altitudes (given by the altitudes_D in rad_here)

lir_achem.compute_ionisation.ionisation_O2_from_O21Dg(rad_here, n_here)[source]

Computes the ionisation of O2(1Dg) from UV radiation As an approximation, following Crutzen et al., 1970 (Figure 1), we will take [O_2 (1Dg)] = 1e10 cm-3 in the atmopshere

The ionisation of O2(1Dg) is computed following Paulsen, 1972 and Swider, 1979, and Krivolutsky, 2015 The ionisation dependence on solar activity is then computed from Pavlov, 2014 Equation 17 and 18. Instead however of using A10.7 in Equation 18, we simply use F10.7

Parameters:

  • rad_here – Radiation class instance

  • n_here – Neutral class instance

lir_achem.compute_ionisation.ionisation_O2_from_XR(Phi_SXR, Phi_HXR, rad_here, n_here, HXR_bins=True)[source]

Computes the ionisation of O2 with resutls from the ionisation of O+, N+ and N2+ then converted into O2+ At first approximation, all N2+ are converted to O2+ (Rowe, 1974, Mitra, 1974) The XR also create O+ and N+, which are converted into NO+ and O2+

Parameters:

  • Phi_HXR (Phi_SXR,) – Absorbed SXR and HXR fluxes

  • rad_here – Radiation class instance

  • n_here – Neutrals class instance

  • HXR_bins – Boolean, default:True. If True, will compute the ionisation from HXR using the bins in rad_here.

lir_achem.compute_ionisation.ion_NOp_from_XR(Phi_SXR, Phi_HXR, rad_here, n_here, HXR_bins=True)[source]

Computes the creation of NO+ with resutls from the ionisation of O+, N+ converted into NO+

Parameters:

  • Phi_HXR (Phi_SXR,) – Absorbed SXR and HXR fluxes

  • rad_here – Radiation class instance

  • n_here – Neutrals class instance

  • HXR_bins – Boolean, if True the ionisation from HXR is computed from the bins in rad_here. (default:True)

lir_achem.compute_ionisation.conversion_OpNp(rad_here, n_here)[source]

Computes the fraction of O+ and N+ converted into NO+ We suppose that O+ is created into its ground state (which is a simplification) and that O+ and N+ do not interact with other species EXCEPT to be converted into either O2+ or NO+. All reactions and reaction rates are from Pavlov, 2014, Table 6

Parameters:

  • rad_here – Radiation class instance

  • n_here – Neutrals class instance

Returns:

  • b_Op Fraction of O+ ions converted into NO+

  • b_Np: Fraction of N+ ions converted into O2+

lir_achem.compute_ionisation.ion_NO_to_NOp(Phi_EUV, rad_here, n_here, sigma_EUV_NOp=2e-18)[source]

Computes the ionisation of NO (in cm-3/s-1) to give NO+. The ionisation cross section come from Watanabe et al., 1967

Parameters:

  • Phi_EUV – Absorbed EUV flux

  • rad_here – Radiation class instance

  • n_here – Neutrals class instance

  • sigma_EUV_NOp – Ionisation cross-section of NO to give NO+ in cm^2 due to SXR (Default: 2e-18 cm^2)

Returns:

Ionisation rate (in part/cm^3 /s) in the D-region altitudes (given by the altitudes_D in rad_here)

lir_achem.compute_ionisation.compute_photon_flux(rad_here, HXR_bins=True)[source]

Here we just convert the solar flux (in W/m^2) to the photon flux (particle/m^2/s)

Parameters:

  • rad_here – Radiation class instance

  • HXR_bins – Boolean (Default: True). If True, Phi_HXR is an array (size 7) with the fluxes for each bin in rad_here