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| Titel |
On the altitude dependence of the spectral characteristics of decametre-wavelength E region backscatter and the relationship with optical auroral forms |
| VerfasserIn |
S. E. Milan, Mark Lester, N. Sato, H. Takizawa |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
0992-7689
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| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 19, no. 2 ; Nr. 19, no. 2, S.205-217 |
| Datensatznummer |
250014204
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| Publikation (Nr.) |
 copernicus.org/angeo-19-205-2001.pdf |
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| Zusammenfassung |
Observations of E region
backscatter by the Ice-land East SuperDARN HF radar from the 30 minute period
2330 to 2400 UT on 13 September 1999 are presented, along with simultaneous
observations of auroral luminosity from two all-sky cameras. Interferometric
techniques are employed to estimate the altitude of origin of each echo observed
by the radar. Under investigation is a region of backscatter which is L-shell
aligned and exists in a region of low auroral luminosity bounded to the north
and the south by two auroral arcs. The spectral characteristics of the
backscatter fall into three main populations: broad, low Doppler shift spectra;
narrow, high Doppler shift spectra; and exceptionally narrow, low Doppler shift
spectra. The first two populations are similar to type II and type I spectra
observed with VHF radars, respectively. These populations scatter from near the
peak of the E region. The high Doppler shift population appears to exist in a
region of sub-critical electric field. The third population originates below the
E region peak at altitudes between 80 and 100 km. We argue that a non-coherent
scattering process is responsible for this backscatter.
Key words. Ionosphere (auroral ionosphere; ionospheric
irregularities) |
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