Dynamics of nonlinear ion-acoustic waves in Venus’ lower ionosphere

• Published in: Astrophysics and space science Vol. 369; no. 5; p. 44
• Main Authors: Chettri, Kusum, Tamang, Jharna, Chatterjee, Prasanta, Saha, Asit
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.05.2024; Springer Nature B.V
• Subjects: Acoustic waves; Amplitudes; Astrobiology; Astronomy; Astrophysics and Astroparticles; Cosmology; Density ratio; Dynamical systems; Ionosphere; Lower atmosphere; Lower ionosphere; Nonlinear dynamics; Nonlinear waves; Observations and Techniques; Perturbation methods; Phase shift; Physics; Physics and Astronomy; Solitary waves; Solitons; Space Exploration and Astronautics; Space Sciences (including Extraterrestrial Physics; Traveling waves; Venus atmosphere; Extreme ultraviolet; Reductive perturbation technique; Multi-soliton; Pioneer Venus orbiter; Phase shift; Solar wind
• ISSN: 0004-640X; 1572-946X
• DOI: 10.1007/s10509-024-04295-6

Dynamics of nonlinear ion-acoustic waves (IAWs) are studied for Venus’ lower atmosphere at an altitude of 200 − 1000 km. Two-soliton, nonlinear solitary and periodic waves in a three-component plasma consisting of H + and O + ions with kappa distributed electrons are studied. Using the reductive perturbation technique (RPT), the Korteweg-de Vries (KdV) equation is derived and a Planar dynamical system is formed for the KdV equation using a travelling wave transformation. A phase portrait is drawn to analyze nonlinear wave behaviors by adjusting the parameters κ (spectral index), γ (unperturbed number density ratio), and V (travelling wave speed). Increasing values of κ amplify amplitudes for solitary and periodic waves, narrow down the width of the solitary wave, and broaden the width of the periodic wave. Increasing value of γ boosts amplitude of the solitary wave with unchanged width, while amplitude of the nonlinear periodic wave decreases and width widens. Increasing value of V enhances amplitudes and reduces widths for both solitary and periodic waves. Two-soliton solutions for the KdV equation are studied using the Hirota direct method. Increasing value of γ reduces amplitude of the soliton without affecting the width and increasing value of κ reduces width of the soliton. Phase shift for two-soliton is also shown and found that for different values of κ , the phase shift increases on increasing value of γ . The findings of our result aid in understanding the dynamics of nonlinear waves and two-soliton solutions in Venus’ lower ionosphere.