Damping and Coupling of Long-Period Hydromagnetic Waves by the Ionosphere
The theory that long-period geomagnetic pulsations are due to hydromagnetic waves resonating in a magnetosphere bounded by an anisotropically conducting ionosphere, insulating atmosphere, and conducting earth, is reviewed. The history of the subject is outlined, covering the effects of the ionospher...
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| Published in | Journal of geomagnetism and geoelectricity Vol. 32; no. Supplement2; pp. SII129 - SII139 |
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| Main Authors | , |
| Format | Journal Article |
| Language | English |
| Published |
Society of Geomagnetism and Earth, Planetary and Space Sciences
1980
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| Online Access | Get full text |
| ISSN | 0022-1392 2185-5765 |
| DOI | 10.5636/jgg.32.Supplement2_SII129 |
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| Summary: | The theory that long-period geomagnetic pulsations are due to hydromagnetic waves resonating in a magnetosphere bounded by an anisotropically conducting ionosphere, insulating atmosphere, and conducting earth, is reviewed. The history of the subject is outlined, covering the effects of the ionospheric boundary on: pulsations seen at ground level and in the ionosphere (ionospheric screening, 90° rotation of polarisation, attenuation of short wavelengths, mode coupling via Hall conductance); and wave systems above the ionosphere (wave-boundary impedance matching, damping, phase variation along the geomagnetic field, and allowed resonances). Coupling of non-axisymmetric modes within the magnetosphere is also mentioned, and a summary of the present picture given, with suggestions for future work. |
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| ISSN: | 0022-1392 2185-5765 |
| DOI: | 10.5636/jgg.32.Supplement2_SII129 |