Two-stream Plasma Instability as a Potential Mechanism for Particle Escape from the Venusian Ionosphere

TL;DR

This study explores how two-stream plasma instability could facilitate the escape of hydrogen and oxygen ions from Venus's ionosphere by analyzing theoretical models and observational data, suggesting a potential escape mechanism.

Contribution

It demonstrates that two-stream instability can transfer enough energy to ions, supported by Venus Express data, to explain particle escape from Venus's ionosphere.

Findings

Two-stream instability can accelerate ions to escape velocity.

Data from Venus Express supports the instability's role in ion escape.

Hydrodynamic model effectively describes the instability process.

Abstract

In this work we investigate the possibility of two-stream instability in the Venusian atmosphere to lead to momentum transfer to subsequent escape of Hydrogen and Oxygen ions from the ionosphere. We employ the hydrodynamic model and obtain the linear dispersion relation from which the two-stream instability is studied. Further the interaction of solar wind with the ions of Venus ionosphere from which the instability sets in, has been studied with the data from ASPERA-4 of Venus Express (VEX). The data supports the fact that the two-stream instability can provide sufficient energy to accelerate ions to escape velocity of the planet.