PROPAGATION OF PCL MICROPULSATIONS IN AN IONOSPHERIC DUCT.
NEWCASTLE UNIV (AUSTRALIA) DEPT OF PHYSICS
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The propagation mechanism of Pc1 micropulsations from their relatively high generation latitude to middle and low latitudes is considered. The study is confined to the type of micropulsations commonly known as pearls or hm emissions. It is shown that propagation probably takes place in a duct centred on the F region of the ionosphere. The diurnal variations of the duct properties are calculated, using typical profiles for the ionospheric parameters at the time of sunspot minimum. It is shown that the duct has a low frequency cutoff at about 0.5 cs, implying that the lack of low frequency events at middle latitudes may be largely a propagation effect. Duct attenuation is very small during the night hours when the majority of Pc1 events are observed at middle latitudes, but is very large during the day. The calculated average horizontal component of the phase velocity for propagation in the duct is of the same order as that given in initial reports of experimental observations. Author
- Atmospheric Physics
- Plasma Physics and Magnetohydrodynamics
- Radiofrequency Wave Propagation