Modeling of the Structure of Long-Period ULF Waves Using Energetic Particle Observations

  1. Gordon R. Wilson
  1. Kazue Takahashi

Published Online: 18 MAR 2013

DOI: 10.1029/GM062p0129

Modeling Magnetospheric Plasma Processes

Modeling Magnetospheric Plasma Processes

How to Cite

Takahashi, K. (1991) Modeling of the Structure of Long-Period ULF Waves Using Energetic Particle Observations, in Modeling Magnetospheric Plasma Processes (ed G. R. Wilson), American Geophysical Union, Washington, D. C.. doi: 10.1029/GM062p0129

Author Information

  1. The Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723-6099

Publication History

  1. Published Online: 18 MAR 2013
  2. Published Print: 1 JAN 1991

ISBN Information

Print ISBN: 9780875900285

Online ISBN: 9781118663905



  • Space plasmas—Mathematical models—Congresses;
  • Magnetosphere—Mathematical models—Congresses


Long-period ULF waves (Pc 5 pulsations) in the magnetosphere are often modeled by a function g(z)ei(mø − ωt), where g(z) represents the field-aligned eigenmode and m is the azimuthal wave number. The model is applicable to a wide variety of waves with different excitation mechanisms. Because each excitation mechanism has a preferred form of g(z) and a preferred value of m, observational determination of g(z) and m is crucial for distinguishing between different generation mechanisms for ULF waves observed at different locations, under different geomagnetic conditions, and with different magnetic field perturbations. In this paper, we discuss how energetic particle measurements from a single spacecraft can be used to determine the spatial structure of ULF waves. Phenomena related to finite Larmor radius effects and driftbounce resonances provide the means with which the wave structure can be remote-sensed. Examples are taken from observations with the Active Magnetospheric Particle Tracer Explorers Charge Composition Explorer (AMPTE CCE) spacecraft in the near-geosynchronous region.