Research Article - invited by the Editors-in-Chief

Remote sensing the plasmasphere, plasmapause, plumes and other features using ground-based magnetometers

¹ School of Mathematical and Physical Sciences, University of Newcastle, Callaghan, NSW 2308 Australia
² Physics Department, University of Alberta, Edmonton, Alberta T6G2J1, Canada
³ British Antarctic Survey, High Cross, Cambridge CB3 0ET, UK

^* Corresponding author: fred.menk@newcastle.edu.au

Received: 15 April 2014
Accepted: 1 October 2014

Abstract

The plasmapause is a highly dynamic boundary between different magnetospheric particle populations and convection regimes. Some of the most important space weather processes involve wave-particle interactions in this region, but wave properties may also be used to remote sense the plasmasphere and plasmapause, contributing to plasmasphere models. This paper discusses the use of existing ground magnetometer arrays for such remote sensing. Using case studies we illustrate measurement of plasmapause location, shape and movement during storms; refilling of flux tubes within and outside the plasmasphere; storm-time increase in heavy ion concentration near the plasmapause; and detection and mapping of density irregularities near the plasmapause, including drainage plumes, biteouts and bulges. We also use a 2D MHD model of wave propagation through the magnetosphere, incorporating a realistic ionosphere boundary and Alfvén speed profile, to simulate ground array observations of power and cross-phase spectra, hence confirming the signatures of plumes and other density structures.