Radiation of ELF/VLF waves by harmonically varying currents into a stratified ionosphere with application to radiation by a modulated electrojet

[1] We use a full-wave finite element approach inspired by the mode calculation method of Wait (1970) to calculate electromagnetic fields in a horizontally stratified ionosphere treated as a magnetized plasma. The source currents can have arbitrary vertical and horizontal distributions. The electromagnetic field is calculated both in the Earth-ionosphere waveguide (at arbitrary horizontal distance and direction) and in the ionosphere (as an upward propagating whistler mode wave). This method requires less computational resources than traditional FDFD and FDTD methods, while providing results with similar accuracy. The model is applied to the radiation of ELF/VLF waves from modulated HF-heated electrojet currents, and the calculated values are compared to ground and satellite observations.

[1]  T. Bell,et al.  HF modulated ionospheric currents , 2007 .

[2]  Umran S. Inan,et al.  DEMETER observations of ELF waves injected with the HAARP HF transmitter , 2006 .

[3]  H. J. Hagger,et al.  Electromagnetic Waves in Stratified Media , 1996 .

[4]  I. Kimura,et al.  Full wave calculation method of VLF wave radiated from a dipole antenna in the ionosphere-analysis of joint experiment by HIPAS and akebono satellite , 1994 .

[5]  K. G. Jr. Budden,et al.  The Propagation of Radio Waves: The Theory of Radio Waves of Low Power in the Ionosphere and Magnetosphere , 1988 .

[6]  T. Nygrén.  A method of full wave analysis with improved stability , 1982 .

[7]  T. Nygrén.  A simple method for obtaining reflection and transmission coefficients and fields for an electromagnetic wave in a horizontally stratified ionosphere , 1981 .

[8]  M. Schoenberg,et al.  Plane wave propagation in stratified anisotropic media , 1974 .

[9]  J. Ratcliffe,et al.  The numerical calculation of wave-fields, reflexion coefficients and polarizations for long radio waves in the lower ionosphere. II , 1965, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[10]  David M. Miller,et al.  Handbook of Mathematical Functions With Formulas, Graphs and Mathematical Tables (National Bureau of Standards Applied Mathematics Series No. 55) , 1965 .

[11]  H. Booker.  Propagation of Wave-Packets Incident Obliquely upon a Stratified Doubly Refracting Ionosphere , 1938 .

[12]  U. Inan,et al.  Emission of ELF/VLF Waves by a Modulated Electrojet upwards into the Ionosphere and into the Earth-Ionosphere Waveguide , 2007 .

[13]  Satoshi Yagitani,et al.  Collaborative experiments by Akebono satellite, Tromsø ionospheric heater, and European incoherent scatter radar , 1994 .

[14]  I. Kimura,et al.  Full wave calculation of ELF/VLF propagation from a dipole source located in the lower ionosphere , 1994 .

[15]  T. H. Stix.  Waves in plasmas , 1992 .