Schumann Resonances in Magnetic-Field Components

Research output: Contribution to journalArticle

Abstract

The Institut fur Geophysik Gottingen has facilities to record the time varying magnetic components H and D at extremely low frequencies (ELF) (0.1-20 Hz) continuously over several days, with a sampling rate of 100 Hz. The lower ELF-range is characterized by anthropogenic noise and the first two Schumann resonance modes of the Earth-ionosphere cavity. The local observations near Gottingen are distributed by thunderstorms during the summer that contribute a small part of the energy to the global thunderstorm activity. Transient natural signals with amplitudes of about 10 pT are superimposed on a continuous noise level of about 1 pT; both exhibit the Schumann resonance periodicities. The signals show a tendency to repeat after about 2 s which may suggest excitation by whistler-trains. The Schumann resonances are investigated by an analysis of the autocovariance matrix yielding a robust estimation of the amplitude, damping and frequency. All these parameters show a characteristic directional dependence and variability during the day. The amplitudes represent the excitation with different source locations of thunderstorm activity around the world, generating a dipole field within the resonator, while the damping and centre-frequency are related to solar activity coupling to the lower ionosphere.
Original languageEnglish
Pages (from-to)479-484
Number of pages6
JournalJournal of Atmospheric and Terrestrial Physics
Volume57
Issue number5
Publication statusPublished - 1995

Fingerprint

Thunderstorms
thunderstorms
thunderstorm
extremely low frequencies
Ionosphere
Magnetic fields
magnetic field
damping
ionosphere
Damping
continuous noise
magnetic fields
Earth ionosphere
lower ionosphere
solar activity
excitation
periodicity
train
summer
periodic variations

Keywords

  • Ionosphere

Cite this

Schumann Resonances in Magnetic-Field Components. / Füllekrug, Martin.

In: Journal of Atmospheric and Terrestrial Physics, Vol. 57, No. 5, 1995, p. 479-484.

Research output: Contribution to journalArticle

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