Solar radiation-induced changes in ionospheric height and the Schumann resonance waveguide on different timescales

E. R. Williams, G. Sátori

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

This study draws together the available observations in the Schumann resonance frequency range to examine the general issue of sensitivity of ionospheric height variations to changes in ionizing radiation from the Sun on different timescales. Ionospheric height can be formally defined, and two characteristic heights are recognized in the Schumann resonance frequency range. In general, order of magnitude changes in radiation are needed to cause relative changes in ionospheric height as large as 10%, as is the case on both the diurnal and 11-year timescales. Changes in EUV radiation are probably insufficiently strong to account for either the 27-day or the 11-year variation in ionospheric height. More ionization-effective X radiation is needed, but much smaller height changes are expected on the solar rotation timescale because the variations in X radiation on this timescale are only tens of percent and not orders of magnitude. The annual variation in radiation from the Sun is only 7%, with an expected height variation less than 100 m, and this remains to be verified by observations. The general insensitivity of the Schumann resonance cavity to changes in ionizing radiation lends stability to the medium that is valuable toward quantifying absolute changes in the global lightning activity on various timescales within the cavity.

Original languageEnglish
Article numberRS2S11
JournalRadio Science
Volume42
Issue number2
DOIs
Publication statusPublished - 2007

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solar radiation
Solar radiation
ionospherics
Waveguides
waveguides
timescale
Radiation
Ionizing radiation
Sun
radiation
ionizing radiation
cavity
sun
frequency ranges
Lightning
solar rotation
Ionization
cavities
sensitivity
lightning

ASJC Scopus subject areas

  • Earth and Planetary Sciences(all)
  • Electrical and Electronic Engineering
  • Condensed Matter Physics

Cite this

Solar radiation-induced changes in ionospheric height and the Schumann resonance waveguide on different timescales. / Williams, E. R.; Sátori, G.

In: Radio Science, Vol. 42, No. 2, RS2S11, 2007.

Research output: Contribution to journalArticle

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