Global surface wave resonances of the earth magnetosphere and their possible manifestation

TL;DR

This paper explores global surface wave resonances in Earth's magnetosphere, proposing they can explain observed Pc5 pulsations as standing wave structures along magnetic field lines, offering an alternative to cavity mode interpretations.

Contribution

It introduces the concept of surface wave resonances supported by plasma discontinuities and ionospheric boundaries, providing a new perspective on magnetospheric pulsations.

Findings

Surface wave resonances can form standing wave structures in the magnetosphere.

Quantized frequencies of these resonances are proportional to integer multiples of a fundamental frequency.

Global Pc5 pulsations may be explained as ultra low-frequency surface wave resonances.

Abstract

In this paper global surface wave modes supported by plasma discontinuities at both the magnetopause and the plasmapause are considered. The ionosphere at the ends of the magnetic field lines of the earth outer magnetosphere is considered as reflecting boundaries of the surface waves that propagate along the plasma boundaries. As a result a standing wave structure along the magnetic field fluxes of the outer magnetosphere, i.e. surface wave resonance structure can be formed. Due to quantized wavenumbers along the magnetic field lines, the surface wave resonance possesses quantified frequencies in a following way: f = nfres, where fres is frequency of the corresponding fundamental surface wave resonance and n is an integer. Global Pc5 pulsations have been observed and interpreted mostly as cavity modes of the earth magnetosphere. The global Pc5 pulsations however could alternatively be interpreted as ultra low-frequency surface wave resonances of the earth magnetosphere that do not necessarily involve the cavity mode-field aligned resonance transformation concept.