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| Titel |
Velocity of E-region HF echoes under strongly-driven electrojet conditions |
| VerfasserIn |
J. D. Gorin, A. V. Koustov, R. A. Makarevich, J.-P. St.-Maurice, S. Nozawa |
| 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 ; 30, no. 1 ; Nr. 30, no. 1 (2012-01-20), S.235-250 |
| Datensatznummer |
250017176
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| Publikation (Nr.) |
 copernicus.org/angeo-30-235-2012.pdf |
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| Zusammenfassung |
| Data collected by the Stokkseyri SuperDARN HF radar simultaneously at short
and far ranges are used to investigate the relationship between the velocity
of E-region HF echoes, E×B electron drift and the
isothermal ion-acoustic speed CS. The work targets large E×B drifts of >1000 m s−1 and observations predominantly along the
flow. By considering the EISCAT temperature and electric field data, an
empirical relationship between the E×B drift velocity and CS is
established for a number of ionospheric heights. For the Stokkseyri HF radar
beams oriented roughly along the E×B direction, the observed
E-region HF velocities are consistent with the CS values at the bottom
of the electrojet but not at its center. For a subset of the data with
smooth and consistent velocity variation with the beam azimuth at both short
and far radar ranges the velocity varies according to the cosine law. For
the E-region echoes, the proportionality coefficient in the cosine law is
consistent with the CS values at the bottom of the electrojet. For these
events, the E-region velocity maximum is shown to be between the E×B
and electric field directions. The statistically average shift is ~20° and it increases slightly with the E×B magnitude. |
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