Characterizing ion-acoustic shock wave collisions in Martian multicomponent plasma environments

TL;DR

This paper theoretically investigates the collision dynamics of ion-acoustic shock waves in Martian multicomponent plasmas, revealing how collisions cause shock broadening and are influenced by plasma composition and viscosity.

Contribution

It introduces a modified Poincaré-Lighthill-Kuo perturbation method to model IA shock collisions in Martian plasma environments with superthermal electrons.

Findings

Shock collisions cause broadening of electrostatic potential profiles.

Kinematic viscosity enhances shock broadening.

Results are based on parameters observed by MAVEN spacecraft.

Abstract

We present theoretical investigation of colliding ion-acoustic (IA) shock waves in Martian multicomponent plasmas consisting of hydrogen ($H^+$), oxygen ($O^+$) and oxygen molecule ($O_2^+$) ions, including background superthermal electrons (modeled by a $\kappa$-(kappa) distribution function). A set of Burgers' equations is obtained by adopting a modified Poincar\'e-Lighthill-Kuo (PLK) perturbation method to describe the head-on-collision dynamics of dissipative nonlinear IA wave structures. We have estimated the spatio-temporal scales using parameters typically observed in the Martian atmosphere by the MAVEN spacecraft, for which shock waves are theoretically expected to undergo mutual collisions in the multicomponent plasma. The effects of head-on collisions on the electrostatic potential profiles arising from one-fold and two-fold IA shock interactions are explored. Our numerical analysis reveals that the collision leads to a noticeable broadening of the shock structures with the enhancement of kinematic viscosity.