A Framework for Efficient Calculation of Photoionization and Photodetachment Rates With Application to the Lower Ionosphere

Abstract

A framework is developed to model photoionization of metals deposited in the lower ionosphere as a result of meteoric ablation and photodetachment of electrons from negative ions of the Earth's ionosphere due to sources of emission other than solar radiation. A wide range of the electromagnetic spectrum including cases of negligible, moderate, and significant absorption of radiation is considered. We limit our scope to the radiation transport through lower ionospheric regions, in case when molecular oxygen, O2, is considered as the main absorber of radiation as photoabsorption due to ozone is only effective at stratospheric altitudes and molecular nitrogen, N2, is transparent to radiation with wavelengths longer than ∼100 nm. We model photon transport in an exponential atmosphere and derive efficient differential representations of the problem in case of negligible photoabsorption and constant pressure approximations. Photoabsorption asymmetry in the atmosphere is demonstrated in case of photons with absorption scales comparable to the scale height of the atmosphere. The application of the model to photoionization in the lower ionosphere is demonstrated by considering photoionization of meteoric species due to photons of the Lyman‐Birge‐Hopfield (LBH) band system of N2 observed in the aurora and in the lightning‐induced transient luminous events. Furthermore, we model detachment of electrons from negative ions of the ionosphere due to the first positive and the second positive band systems of N2, and the first negative band system of N 2+, also observed in the sources mentioned above.

Adaptive strategies to fast multipole method in photoionisation calculations for streamer discharges

“…It is worth mentioning that the introduced FMM is based on quadrature in (15), which is not limited to the model in (1) and could be applied to other integral models (e.g., [27,28]).…”

“…This integral model was then improved and extended in Ref. [26][27][28]. However, its direct implementation requires a large amount of computation especially in three dimensions (3D), since the calculation of the photoionisation at one specific point requires a quadrature over the whole simulation domain.…”

Simulation study on influence of oxygen concentrations on atmospheric-pressure streamer in oxygen-rich nitrogen–oxygen mixture

“…To describe the photoionisation process induced by monochromatic light with a wavelength λ 0 = 98.9 nm, the general framework for photoionisation calculations, as outlined in [44,51], is applied. Specifically, the absorption function of the photons with the wavelength of λ 0 = 98.9 nm applied in equation ( 7) emitted by O 2 can be expressed as…”

Multi-scale two-domain numerical modeling of stationary positive DC corona discharge/drift-region coupling

“…γ 1, to account for the photo-ionization cross-section and probability as in [43,44]. The photon radiative kernel may have different forms [45,1,46,47]. We hereby derive a general theory which can be adapted to any (regular) form of kernel.…”