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In 1976, Polyakov (1976) predicted the existence of ionospheric
Alfvén resonator (IAR), equivalent to the ionospheric waveguide,
but operating in vertical direction with shear Alfvén waves.
According to the theory, further developed by Polyakov and Rapoport (1981), waves can be
trapped between two altitudes characterized by large Alfvén velocity gradients: the lower
limit occurs at ionospheric F-layer, the upper limit at about 3000 km. For a recent
review, see, e.g., Lysak (1993).
The so-called spectral resonance structures (SRS) discovered by Belyaev et al. (1989,
1990) are considered to be an evidence for IAR. They are thought to form within the IAR
from electromagnetic emissions of lightning charges, just like the Schumann
resonances. Up to fifteen bands can be observed, from the 1-2 Hz (Pc1
range) to well above the second Schumann resonance frequency at 14 Hz. After the original
finding of SRS at mid-latitudes, they have now been observed also at high-latitudes
(Belyaev et al., 1998; see also the figure).
Note that it has been suggested that a special Pc1 pulsation type, the pearl
pulsations, could be explained by IAR based Alfvén maser (Belyaev et al., 1984).
- Belyaev, P. P., S. V. Polyakov, V. O. Rapoport, and V. Y. Trakhtengerts, The fine
structure of the radiation of an Alfvén maser, Geomagn. Aeron., 24, 202-205,
- Belyaev, P. P., S. V. Polyakov, V. O. Rapoport, and V. Y. Trakhtengerts, Experimental
studies of the spectral resonance structure of the atmospheric electromagnetic noise
background within the range of short-period geomagnetic pulsations, Radiophizika, 32,
- Belyaev, P. P., S. V. Polyakov, V. O. Rapoport, and V. Y. Trakhtengerts, The ionospheric
Alfvén resonator, J. Atm. Terr. Phys., 52, 781-788, 1990.
- Belyaev, P. P., T. Bösinger, S. V. Isaev, V. Y. Trakhtengerts, and J. Kangas, First
evidence at high latitudes for Ionospheric Alfvén resonator, J. Geophys. Res.,
in press, 1998.
- Lysak, R. L., Generalized model of the Ionospheric Alfvén resonator, in Auroral
Plasma Dynamics, Geophysical Monograph 80, edited by R. L. Lysak, pp. 121-128,
American Geophysical Union, Washington, 1993.
- Polyakov, S. V., On properties of an ionospheric Alfvén resonator, in Symposium KAPG
on Solar-Terrestrial Physics, vol. III, pp. 72-73, Nauka, Moscow, 1976.
- Polyakov, S. V. and V. O. Rapoport, Ionospheric Alfvén resonator, Geomagn.
Aeron., 21, 610-614, 1981.