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| Titel |
Volume cross sections of auroral backscatter and amplitudes of electrostatic electrojet fluctuations inferred from joint STARE and EISCAT CP-1 measurements |
| VerfasserIn |
M. Uspensky, A. Koustov, P. Janhunen  |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250026149
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| Zusammenfassung |
| Norway and Finland STARE radar data are combined with CP-1 EISCAT measurements of
the electron density and electric field vector in the ionosphere to investigate the variation of
the auroral radar volume cross section (RVCS) with the flow angle of observations (radar
look direction with respect to the ExB electron drift). Our statistics consists of ~ 6000
points for flow angles of 40-85o and electron drifts between 500 and 2000 m/s.
The electron density data are used to estimate the effective electron density and
thickness of the scattering layer. It is shown that the flow angle variation of the
RVCS is significantly weaker than reported in the past (only ~ 5 dB within the
range of available flow angles) and it is not symmetric with respect to the direction
of the electron drift. By adopting the inferred shape of the RVCS variation with
the flow angle and using an assumed dependence of the RVCS upon wavelength
(as reported in literature), the relative amplitude of electrostatic electrojet density
fluctuations at all scales, -¨(δN -N )2-©1-2, is estimated. The obtained values of
several (up to 10) per cent are consistent with reported in situ rocket measurements.
The RVCS and -¨(δN -N)2-©1-2 values are also shown to depend almost linearly
on the square of the electron drift velocity magnitude and the effective electron
density. |
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