Remote sensing of D-region ionosphere using multimode tweeks

A. K. Singh, U. P. Verma, R. Singh, J. Lichtenberger

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1 Citation (Scopus)


Lightning discharges radiate electromagnetic waves in a wide frequency range, with maximum energy in extremely low frequency/very low frequency band. A part of the radiated extremely low frequency/very low frequency wave energy is trapped in the Earth–ionosphere waveguide and travels thousands of kilometers in different modes with lower attenuation. Amplitude, frequency and phase of these waves are used to study the less explored D-region ionosphere at lower latitudes. Extremely low frequency/very low frequency observations are recorded continuously by automatic whistler detector setup installed at low-latitude Indian station Lucknow (Geom. lat. 17.6°N; long. 154.5°E). In total, 149 cases of tweeks having modes ranging from 3 to 6 have been recorded by automatic whistler detector during December 2010 and analyzed. Result shows that the propagation distance in the Earth–ionosphere waveguide lies between 1.1 and 9.4 Mm. The electron density in the lower D-region varies between 25 and 150 cm−3. The upper boundary of the waveguide varies between 80 and 95 km. The reported results are in good agreement with the earlier measurements at different latitudes and longitudes.

Original languageEnglish
Pages (from-to)1-7
Number of pages7
JournalIndian Journal of Physics
Issue number1
Publication statusPublished - Jan 1 2016



  • Earth–ionosphere waveguide
  • Electron density
  • Lightning
  • Propagation distance
  • Reflection height
  • Tweeks/sferics

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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