Electrostatic Solitary Waves in the Venusian Ionosphere Pervaded by the Solar Wind: A Theoretical Perspective

Abstract

Electrostatic solitary waves (ESWs) in the Venusian ionosphere that are impinged by the solar wind are investigated using a homogeneous, collisionless, and magnetized multicomponent plasma consisting of Venusian H+ and O+ ions, Maxwellian Venusian electrons and streaming solar wind protons, and suprathermal electrons following κ − distribution. The model supports the propagation of positive potential slow O+ and H+ ion-acoustic solitons. The evolution and properties of the solitons occurring in two sectors, viz., dawn-dusk and noon-midnight sector of the Venus ionosphere at an altitude of (200–2000) km, are studied. The theoretical model predicts positive potential solitons with amplitude ∼(0.067–56) mV, width ∼(1.7–53.21) m, and velocity ∼(1.48–8.33) km s−1. The bipolar soliton electric field has amplitude ∼(0.03–27.67) mV m−1 with time duration ∼(0.34–22) ms. These bipolar electric field pulses when Fourier transformed to the frequency domain occur as a broadband electrostatic noise, with frequency varying in the range of ∼9.78 Hz–8.77 kHz. Our results can explain the observed electrostatic waves in the frequency range of 100 Hz–5.4 kHz in the Venus ionosphere by the Pioneer Venus Orbiter mission. The model can also be relevant in explaining the recent observation of ESWs in the Venus magnetosheath by the Solar Orbiter during its first gravity assist maneuver of Venus.

Propagation of nonlinear ion-acoustic fluctuations in the mantle of Venus

“…6. We applied this procedure to both cases, but we only included the oblique propagation case because the quasiparallel propagation case results match the results obtained by Salem et al (2022) and Rubia et al (2023). The estimates of A17, page 7 of 13 Morsi, S. A., et al: A&A, 685, A17 (2024) (Scarf et al 1979;Yadav 2021).…”

“…They showed that the electric pulses associated with the solitary waves when they are Fourier transformed into the frequency domain could generate a broadband electrostatic noise in the frequency range of 0.1-4 kHz, which is in line with the spacecraft observations. Rubia et al (2023) explored the features of the arbitrary amplitude ESWs propagating at both the noon-midnight and dawn-dusk sectors in the Venusian ionosphere and transition zone. They took into consideration the population of superthermally distributed electrons in the solar wind.…”

The characteristics of ion acoustic solitons in nonthermal regularized kappa distributed plasmas

“…Note that there exist various multiple component models of acoustic solitons for the applications of space and planetary environments. 2,[18][19][20][21][22][23] In the context of dynamic evolution, the effect of KVD electrons on the formation of IASs has been examined by the numerical simulations of the fluid models. 24 In most of the existing models for IASs with kinetic electrons, the ions are described by the fluid equations with zero temperature which, however, do not correspond to the real space plasma environments.…”

“…By assuming the adiabatic law with c ¼ 3 corresponding to one degree of freedom for the ions, the modified Sagdeev's potential have been derived for the ion and dust acoustic solitons with Kappa and Cairns et al distributed electrons. 2,22,23,25 Note that there exist some fluid models of acoustic solitons that are not limited to cold ions, but in those studies, the electrons are not described by the kinetic equilibrium. 26,27 In the fluid models of IASs, in which the electrons are not in kinetic equilibrium, the Sagdeev's potential method has also been adopted to derive the soliton solutions.…”