Three‐dimensional finite difference time domain modeling of the diurnal and seasonal variations in Schumann resonance parameters

Abstract

[1] The diurnal and seasonal variations of Schumann resonances (SR) have been reported in a number of experiments. In this paper, a three-dimensional FDTD model of the Earth-ionosphere cavity with a day-night asymmetric conductivity profile is employed to study the diurnal and seasonal variability of the power and frequency of the first Schumann resonance (SR) mode. Comparison of the FDTD results and recent experimental measurements shows a clear modulation in the SR power related to the local ionospheric height and global lightning activity. It is found that SR frequencies are not only a function of the local time but also are controlled by the global lightning activity changing with universal time.

Schumann resonances: Interpretation of local diurnal intensity modulations

“…PECHONY AND PRICE: DIURNAL MODULATIONS OF SR dominant role, while the ionosphere height effect appears to have a minor influence on the observed variations in SR field intensities [Large and Wait, 1968;Bliokh et al, 1980;Nickolaenko, 1986;Rabinowicz, 1988;Nickolaenko and Hayakawa, 2002;Yang and Pasko, 2006;Pechony et al, submitted manuscript, 2006].…”

“…Nevertheless, the source-receiver distance effects are considered to be significant and cannot be completely neglected in favor of the much weaker [Large and Wait, 1968;Bliokh et al, 1980;Nickolaenko, 1986;Rabinowicz, 1988;Nickolaenko and Hayakawa, 2002;Yang and Pasko, 2006;Pechony et al, submitted manuscript, 2006] daynight asymmetry influence. The aim of the present work is to show, using a controlled model experiment, that the local modulation function introduced by SF cannot be associated with variations in the ionosphere height and that SF in fact developed an elegant technique of eliminating the source-receiver distance effect.…”

Numerical analysis of ionosphere disturbances and Schumann mode splitting in the Earth‐ionosphere cavity

“… Pechony and Price [2004] made theoretical calculations showing that the variability of SR is associated to the distance to the thunderstorm activity area. However in the work of Yang and Pasko [2005, 2006], about the Earth, and previous results using the finite difference time domain (FDTD) technique [ Soriano et al , 2007] on the Mars ionosphere shown that SR frequencies would change under strong variations of the conductivity at altitudes below certain altitude (in Mars 100 km).…”

FDTD modeling of diurnal/seasonal variations of Schumann resonance

“…Researches on the Schumann resonance parameters (SRs) of the Earth-ionosphere (E-I) system have been reported in many papers [1][2][3] in the recent years. It is believed the properties of SRs (frequencies and quality factors) can reveal physical characteristics of the E-I system such as global temperature, lightning distribution, earthquake phenomena, etc [3].…”

“…It is believed the properties of SRs (frequencies and quality factors) can reveal physical characteristics of the E-I system such as global temperature, lightning distribution, earthquake phenomena, etc [3]. Because accurate SRs variation simulation requires to model the extremely low frequency (ELF) electromagnetic wave propagation and the geology/geodesic information in the whole complex E-I system, it is not until recent years that time-domain numerical algorithms have been applied to such problems [1][2].…”