Resonant cavities and waveguides in the ionosphere and atmosphere

R. L. Lysak, Akimasa Yoshikawa

Research output: Chapter in Book/Report/Conference proceedingChapter

14 Citations (Scopus)

Abstract

The strong inhomogeneities in plasma parameters in the ionosphere and adjacent regions can trap waves in the upper end of the ULF range (Pc1/Pi1). The topside ionosphere is characterized by a rapidly increasing Alfvén speed with a scale height on the order of 1000 km. Shear-mode Alfvén waves in this region can be partially trapped at frequencies in the 0.1-1.0 Hz range. The same structure can trap fast-mode compressional waves in this frequency band. Since these waves can propagate across magnetic field lines, this structure constitutes a waveguide in which energy can propagate at speeds comparable to the Alfvén speed, typically on the order of 1000 km/s. Hall effects in the ionosphere couple these two wave modes, so that the introduction of a field-aligned current by means of a shearmode Alfvén wave can excite compressional waves that can propagate in the waveguide. In the limit of infinite ionospheric conductivity, these waves are isolated from the atmospheric fields; however, for finite conductivity, ionospheric and atmospheric waves are coupled. Transverse magnetic modes in the atmosphere can propagate at ULF frequencies and form global Schumann resonances with the fundamental at 8 Hz. It has been suggested that signals that propagate at the speed of light through this atmospheric waveguide can rapidly transmit signals from the polar region to lower latitudes during sudden storm commencements.

Original languageEnglish
Title of host publicationMagnetospheric ULF Waves
Subtitle of host publicationSynthesis and New Directions, 2006
PublisherBlackwell Publishing Ltd.
Pages289-306
Number of pages18
ISBN (Electronic)9781118666319
ISBN (Print)9780875904344
DOIs
Publication statusPublished - Jan 1 2006

Publication series

NameGeophysical Monograph Series
Volume169
ISSN (Print)0065-8448
ISSN (Electronic)2328-8779

Fingerprint

cavity resonators
ionospheres
ionosphere
cavity
waveguides
atmospheres
atmosphere
ionospheric conductivity
conductivity
atmospheric conductivity
sudden storm commencements
traps
atmospheric wave
field aligned currents
scale height
polar region
inhomogeneity
tropical regions
polar regions
Hall effect

All Science Journal Classification (ASJC) codes

  • Geophysics

Cite this

Lysak, R. L., & Yoshikawa, A. (2006). Resonant cavities and waveguides in the ionosphere and atmosphere. In Magnetospheric ULF Waves: Synthesis and New Directions, 2006 (pp. 289-306). (Geophysical Monograph Series; Vol. 169). Blackwell Publishing Ltd.. https://doi.org/10.1029/169GM19

Resonant cavities and waveguides in the ionosphere and atmosphere. / Lysak, R. L.; Yoshikawa, Akimasa.

Magnetospheric ULF Waves: Synthesis and New Directions, 2006. Blackwell Publishing Ltd., 2006. p. 289-306 (Geophysical Monograph Series; Vol. 169).

Research output: Chapter in Book/Report/Conference proceedingChapter

Lysak, RL & Yoshikawa, A 2006, Resonant cavities and waveguides in the ionosphere and atmosphere. in Magnetospheric ULF Waves: Synthesis and New Directions, 2006. Geophysical Monograph Series, vol. 169, Blackwell Publishing Ltd., pp. 289-306. https://doi.org/10.1029/169GM19
Lysak RL, Yoshikawa A. Resonant cavities and waveguides in the ionosphere and atmosphere. In Magnetospheric ULF Waves: Synthesis and New Directions, 2006. Blackwell Publishing Ltd. 2006. p. 289-306. (Geophysical Monograph Series). https://doi.org/10.1029/169GM19
Lysak, R. L. ; Yoshikawa, Akimasa. / Resonant cavities and waveguides in the ionosphere and atmosphere. Magnetospheric ULF Waves: Synthesis and New Directions, 2006. Blackwell Publishing Ltd., 2006. pp. 289-306 (Geophysical Monograph Series).
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