scholarly journals Use of the International Reference Ionosphere 2012 model to calculate emission frequency scale of the ionospheric Alfvén resonator

2015 ◽  
Vol 5 ◽  
pp. A14 ◽  
Author(s):  
Alexander S. Potapov ◽  
Tatyana N. Polyushkina ◽  
Boris V. Dovbnya
Keyword(s):  
International Reference Ionosphere ◽  
Emission Frequency ◽  
International Reference ◽  
Ionospheric Alfvén Resonator ◽  
Frequency Scale ◽  
Alfven Resonator ◽  
Ionospheric Alfven Resonator

scholarly journals An automatic method to determine the frequency scale of the ionospheric Alfvén resonator using data from Hylaty station, Poland

2006 ◽  
Vol 24 (8) ◽  
pp. 2151-2158 ◽  
Author(s):  
A. Odzimek ◽  
A. Kułak ◽  
A. Michalec ◽  
J. Kubisz
Keyword(s):  
Field Data ◽  
Automatic Method ◽  
Frequency Range ◽  
Magnetic Field Data ◽  
Ionospheric Alfvén Resonator ◽  
Frequency Scale ◽  
Alfven Resonator ◽  
Using Data ◽  
Ionospheric Alfven Resonator ◽  
Elf Magnetic Field

Abstract. ULF/ELF magnetic field data recorded at the "Hylaty" station in Poland (49°19' N, 22°56' E; L≃2) are analysed to find the characteristics of spectral resonance structures (SRS) in the frequency range 1–5 Hz, related to the ionospheric Alfvén resonator (IAR). An automatic procedure is employed to SRS events observed at "Hylaty" during the nighttime in 2001–2003, to calculate the parameter which determines the separation between the harmonics of the resonator, termed the frequency scale. Diurnal and seasonal variations of the frequency scale within the range of 0.4–0.8 Hz have been found. The usefulness and disadvantages of this particular method of SRS analysis, and of other methods, are discussed.

scholarly journals Morphology and diagnostic potential of the ionospheric Alfvén resonator

2021 ◽  
Vol 7 (3) ◽  
pp. 36-52
Author(s):  
Alexander Potapov ◽  
Tatyana Polyushkina ◽  
B. Tsegmed
Keyword(s):  
Magnetic Field ◽  
Alfven Waves ◽  
Alfvén Waves ◽  
Field Frequency ◽  
Emission Frequency ◽  
Ionospheric Alfvén Resonator ◽  
Diagnostic Potential ◽  
Wide Range ◽  
Alfven Resonator ◽  
Ionospheric Alfven Resonator

The layering of the ionosphere leads to the formation of resonators and waveguides of various kinds. One of the most well-known is the ionospheric Alfvén resonator (IAR) whose radiation can be observed both on Earth’s surface and in space in the form of a fan-shaped set of discrete spectral bands (DSB), the frequency of which changes smoothly during the day. The bands are formed by Alfvén waves trapped between the lower part of the ionosphere and the altitude profile bending of Alfvén velocity in the transition region between the ionosphere and the magnetosphere. Thus, IAR is one of the important mechanisms of the ionosphere-magnetosphere interaction. The emission frequency lies in the range from tenths of hertz to about 8 Hz — the frequency of the first harmonic of the Schumann resonance. The review describes in detail the morphology of the phenomenon. It is emphasized that the IAR emission is a permanent phenomenon; the probability of observing it is primarily determined by the sensitivity of the equipment and the absence of interference of natural and artificial origin. The daily duration of the DSB observation almost completely depends on the illumination conditions of the lower ionosphere: the bands are clearly visible only when the D layer is shaded. Numerous theoretical IAR models have been systematized. All of them are based on the analysis of the excitation and propagation of Alfvén waves in inhomogeneous ionospheric plasma and differ mainly in sources of oscillation generation and methods of accounting for various factors such as interaction of wave modes, dipole geometry of the magnetic field, frequency dispersion of waves. Predicted by all models of the cavity and repeatedly confirmed experimentally, the close relationship between DSB frequency variations and critical frequency foF2 variations serves as the basis for searching ways of determining in real time the electron density of the ionosphere from IAR emission frequency measurements. It is also possible to estimate the profile of the ion composition over the ionosphere from the data on the IAR emission frequency structure. The review also focuses on other results from a wide range of IAR studies, specifically on the results that revealed the influence of the interplanetary magnetic field orien tation on oscillations of the resonator, and on the facts of the influence of seismic disturbances on IAR.

scholarly journals Morphology and diagnostic potential of the ionospheric Alfvén resonator

2021 ◽  
Vol 7 (3) ◽  
pp. 39-56
Author(s):  
Alexander Potapov ◽  
Tatyana Polyushkina ◽  
B. Tsegmed
Keyword(s):  
Magnetic Field ◽  
Alfven Waves ◽  
Alfvén Waves ◽  
Field Frequency ◽  
Emission Frequency ◽  
Ionospheric Alfvén Resonator ◽  
Diagnostic Potential ◽  
Wide Range ◽  
Alfven Resonator ◽  
Ionospheric Alfven Resonator

The layering of the ionosphere leads to the formation of resonators and waveguides of various kinds. One of the most well-known is the ionospheric Alfvén resonator (IAR) whose radiation can be observed both on Earth’s surface and in space in the form of a fan-shaped set of discrete spectral bands (DSB), the frequency of which changes smoothly during the day. The bands are formed by Alfvén waves trapped between the lower part of the ionosphere and the altitude profile bending of Alfvén velocity in the transition region between the ionosphere and the magnetosphere. Thus, IAR is one of the important mechanisms of the ionosphere-magnetosphere interaction. The emission frequency lies in the range from tenths of hertz to about 8 Hz — the frequency of the first harmonic of the Schumann resonance. The review describes in detail the morphology of the phenomenon. It is emphasized that the IAR emission is a permanent phenomenon; the probability of observing it is primarily determined by the sensitivity of the equipment and the absence of interference of natural and artificial origin. The daily duration of the DSB observation almost completely depends on the illumination conditions of the lower ionosphere: the bands are clearly visible only when the D layer is shaded. Numerous theoretical IAR models have been systematized. All of them are based on the analysis of the excitation and propagation of Alfvén waves in inhomogeneous ionospheric plasma and differ mainly in sources of oscillation generation and methods of accounting for various factors such as interaction of wave modes, dipole geometry of the magnetic field, frequency dispersion of waves. Predicted by all models of the cavity and repeatedly confirmed experimentally, the close relationship between DSB frequency variations and critical frequency foF2 variations serves as the basis for searching ways of determining in real time the electron density of the ionosphere from IAR emission frequency measurements. It is also possible to estimate the profile of the ion composition over the ionosphere from the data on the IAR emission frequency structure. The review also focuses on other results from a wide range of IAR studies, specifically on the results that revealed the influence of the interplanetary magnetic field orien tation on oscillations of the resonator, and on the facts of the influence of seismic disturbances on IAR.

The splitting effect of the mode structure of the ionospheric alfven resonator

2015 ◽  
Vol 21 (1(92)) ◽  
pp. 58-63
Author(s):  
N.A. Baru ◽  
◽  
A.V. Koloskov ◽  
Y.M. Yampolski ◽  
◽  
...  
Keyword(s):  
Mode Structure ◽  
Ionospheric Alfvén Resonator ◽  
Alfven Resonator ◽  
Ionospheric Alfven Resonator ◽  
Splitting Effect

Pc 1 waves and ionospheric Alfvén resonator: Generation or filtration?

2000 ◽  
Vol 27 (23) ◽  
pp. 3805-3808 ◽  
Author(s):  
A. G. Demekhov ◽  
V. Yu. Trakhtengerts ◽  
T. Bösinger
Keyword(s):  
Ionospheric Alfvén Resonator ◽  
Alfven Resonator ◽  
Ionospheric Alfven Resonator

scholarly journals Ionospheric Alfvén resonator revisited: Feedback instability

2001 ◽  
Vol 106 (A11) ◽  
pp. 25813-25824 ◽  
Author(s):  
Oleg A. Pokhotelov ◽  
V. Khruschev ◽  
M. Parrot ◽  
S. Senchenkov ◽  
V. P. Pavlenko
Keyword(s):  
Ionospheric Alfvén Resonator ◽  
Alfven Resonator ◽  
Ionospheric Alfven Resonator

scholarly journals An effect of the ionospheric Alfvén resonator on multiband Pc1 pulsations

2004 ◽  
Vol 22 (2) ◽  
pp. 643-651 ◽  
Author(s):  
K. Prikner ◽  
K. Mursula ◽  
J. Kangas ◽  
R. Kerttula ◽  
F. Z. Feygin
Keyword(s):  
Ionospheric Alfvén Resonator ◽  
High Latitude Ionosphere ◽  
Distinct Frequency ◽  
Radar Measurements ◽  
Pc1 Pulsations ◽  
Alfven Resonator ◽  
Eiscat Radar ◽  
Ionospheric Alfven Resonator ◽  
Ionospheric Resonator ◽  
Large Frequency

Abstract. On 2 December 1999, the magnetometer stations in northern Finland registered structured Pc1 activity simultaneously in three distinct frequency bands. Using simultaneous EISCAT radar measurements of the high-latitude ionosphere, we have studied the ionospheric resonator properties during this multiband Pc1 event. The frequencies of the three structured Pc1 bands were found to closely correspond to the second, third and fourth harmonic of the calculated fundamental frequency of the ionospheric Alfvén resonator (IAR). In addition, those frequencies of the three pearl bands that were closest to the exact IAR harmonics were found to have the strongest intensities. The results demonstrate that the resonator can have an important role on ground-based Pc1 activity over a notably large frequency range, favoring transmission of waves with frequencies close to the resonator's eigenfrequencies. Since the frequencies of all three bands correspond to the maximum rather than the minimum of the transmission coefficient, the traditional bouncing wave packet model needs to be revised. Key words. Ionosphere (auroral ionosphere; ionosphere magnetosphere interactions; wave propagation)

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