Study of hydromagnetic solitary waves in the Earth's inner magnetosphere via the Adlam-Allen model

Abstract

Solitary hydromagnetic waves propagating perpendicular to the ambient magnetic field are nonlinear structures that were first analysed by Adlam and Allen in 1958. Although they were first studied for electron-ion plasmas in the controlled thermonuclear reaction experiment, they can also occur in other plasma media. Satellite observations have confirmed that these large-amplitude hydromagnetic waves are ubiquitous in many space plasma environments. In this paper, using Sagdeev pseudopotential technique, we study the properties of large amplitude hydromagnetic waves using the physical model employed by Adlam-Allen. It is confirmed that the waves exist with Mach numbers within the range from 1 to 2. Applications to observations of di-polarization fronts (DFs) in the Earth's inner magnetosphere are discussed.