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3rd LOIS Workshop, November 24-25, 2002 Växjö University, Växjö, Sweden |
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HF diagnostics of topside ionospheric plasma
Hanna Rothkaehl, Zbigninew Klos, and Stan Grzedzielski
hrot@cbk.waw.pl, director@cbk.waw.pl, stangrze@cbk.waw.pl
Space Research Centre PAS
Bartycka 18A
00-716 Warsaw, Poland
Hanna Rothkaehl, Zbigninew Klos, and Stan Grzedzielski
hrot@cbk.waw.pl, director@cbk.waw.pl, stangrze@cbk.waw.pl
Space Research Centre PAS
Bartycka 18A
00-716 Warsaw, Poland
AbstractThe electromagnetic emission in the topside ionosphere has been investigated since the first satellites were put in orbit. Such RF measurements can be used to diagnose the different electron plasma waves as well as the electron ionospheric density. The paper presents the global picture of RF radio noise in the 0.1-15 MHz frequency range, detected on board of low orbiting satellite CORONAS-I. The well-manifested global distribution feature of the observed spectra appears as remarkable enhancement of spectral density over Europe and part of Asia. The aim of this paper is to discuss the mechanism of the increased background radiation as well as the broad band RF emission and correlation these events with human activity.
The changes of the ionospheric plasma properties are driven not only by
the Sun, but occasionally sudden ionospheric changes (nighttime
ionisation enhancements) are resulting from impulsive bursts of gamma
and X-ray emission of SGR sources (Soft Gamma Repeaters) and, perhaps,
other astrophysical sources of hard radiation. The future research
program could help to improve the statistics of known objects of this
type and contribute to the estimate of fluxes of low-energy X-rays that
accompany gamma-ray flares.
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