The effect of subionospheric propagation on whistlers recorded by the DEMETER satellite – observation and modelling

O.E. Ferencz (1) , Cs. Ferencz (1) , P. Steinbach (2) , J. Lichtenberger (1) , D. Hamar (1) , Michel Parrot (3) , François Lefeuvre (3) , Jean-Jacques Berthelier (4)

1 Space Research Group
2 MTA-ELTE Research Group for Geology, Geophysics and Space Sciences
3 LPCE - Laboratoire de physique et chimie de l'environnement
4 CETP - Centre d'étude des environnements terrestre et planétaires

During a routine analysis of whistlers on the wide-band VLF recording of the DEMETER satellite, a specific signal structure of numerous fractional-hop whistlers, termed the "Spiky Whistler" (SpW) was identified. These signals appear to be composed of a conventional whistler combined by the compound mode-patterns of guided wave propagation, suggesting a whistler excited by a lightning "tweek" spheric. Rigorous, full-wave modelling of tweeks, formed by the long subionospheric guided spheric propagation and of the impulse propagation across an arbitrarily inhomogeneous ionosphere, gave an accurate description of the SpW signals. The electromagnetic impulses excited by vertical, preferably CG lightning discharge, exhibited the effects of guided behaviour and of the dispersive ionospheric plasma along their paths. This modelling and interpretation provides a consistent way to determine the generation and propagation characteristics of the recorded SpW signals, as well as to describe the traversed medium.

Domaines: Astrophysique [astro-ph]; Physique Atmosphérique et Océanique [physics.ao-ph]; Physique des plasmas [physics.plasm-ph]

O.E. Ferencz, Cs. Ferencz, P. Steinbach, J. Lichtenberger, D. Hamar, et al.. The effect of subionospheric propagation on whistlers recorded by the DEMETER satellite – observation and modelling. Annales Geophysicae, 2007, 25 (5), pp.1103-1112. ⟨10.5194/angeo-25-1103-2007⟩. ⟨hal-00322842⟩