Daily-Seasonal Variation in the Number of Remotely Observed,Pulsed, ULF Electromagnetic Earthquakes and the Spatial Distribution of Their Generation Zones on the Earth’s Surface

Geomagnetism and Aeronomy - Based on data from long-term observations at two geophysical observatories, Borok and College, distantly spaced in latitude and longitude, the results of remote...     

Hydromagnetic emission of the interplanetary plasma

A new type of geomagnetic pulsation — the serpentine emission — has been discovered in the 0–2 Hz range. The particular feature which characterizes the serpentine emission is the wide modulation of the carrier frequency. A theory to account for this type of disturbance involves radiation from the solar wind. The frequency modulation is explained in terms of Doppler shifts and variation of the direction of the interplanetary magnetic field.     

Earthquake impact on ionospheric Alfvén resonances

According to BGO data, it is discovered that ionospheric Alfvén resonances (IARs) observed as geomagnetic pulsations at frequencies of a few hertz arise in response to seismic events. The paper presents examples showing how seismic waves affect the IAR regime. Possible mechanisms of this effect are discussed.     

Estimating the Frequency and Amplitude Parameters of the Serpentine-Emission Type of Geomagnetic Pulsations

Geomagnetic pulsations of the serpentine-emission (SE) type are considered. A method for estimating the frequency and amplitude parameters in the form of a time function for pulsations—SE and the accompanying spectral components—is suggested. An estimation algorithm is developed on the basis of local approximating polyharmonic models and weighted moving average filtration. Examples of the estimation of the frequency and amplitude parameters of SE pulsations are given. It is proposed that the procedure be used to calculate the estimation errors in SE pulsation frequency parameters and to choose the tuning parameters.     

Influence of Substorm Activity on the Formation of Ultra Low Frequency Noise Emissions in the Frequency Range of 0–7 Hz

Geomagnetism and Aeronomy - The results of the study of simultaneous observations of midlatitude ultra low frequency (ULF) noise emissions in the frequency range of 0–7 Hz and disturbances in...     

Electromagnetic signals close in time to earthquakes

The search for electromagnetic effects of earthquakes has discovered pulsed signals preceding or following the time of an event. The advance or lag amounts to 0–5 min. The signals are observed as single or paired pulses in the frequency range 0–5 Hz. Dynamic spectra of the signals are presented and their characteristics are discussed. A hypothesis on the seismoelectromagnetic origin of the signals is suggested and verified.     

The Frequency Modulation of Serpentine Emission as Compared to the Set of the Known Periodicities of Solar Oscillations

Based on the data from the Vostok station, Antarctica, for the period from 1966 to 1971, the frequency modulation of the serpentine-emission-type (SE) geomagnetic pulsations is studied. The spectral analysis of the selected emission events revealed a number of modulation periods in the interval from 1 to 60 min. The 5-min SE modulation period is most common. The obtained results are compared to the observations of solar atmosphere oscillations. The correspondence of the periods of the SE frequency modulation to the periods of oscillations of the solar photosphere is established. This confirms the previously suggested hypothesis of the existence of a genetic connection between the frequency modulation of the emission and oscillations of the solar surface.     

Dynamics of Ionospheric Alfvén Resonances from the End of Cycle 21 through Cycle 24 of Solar Activity

Geomagnetism and Aeronomy - The results of the study of the dynamics of ionospheric Alfvén resonances (IARs) in a range of 0–10 Hz based on data from magnetic field observations at the...