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| Titel |
Factors determining spectral width of HF echoes from high latitudes |
| VerfasserIn |
P. V. Ponomarenko, C. L. Waters, F. W. Menk |
| 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 ; 25, no. 3 ; Nr. 25, no. 3 (2007-03-29), S.675-687 |
| Datensatznummer |
250015807
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| Publikation (Nr.) |
 copernicus.org/angeo-25-675-2007.pdf |
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| Zusammenfassung |
| Spectral width is one of the standard data types produced by the Super Dual
Auroral Radar Network (SuperDARN). A pronounced latitudinal gradient in
spectral width has been reported in the literature and is used as an
empirical proxy for the ionospheric footprint of the open-closed field-line
boundary. In this work we investigated the daytime radar echo properties near
the spectral width boundary using a multi-frequency sounding regime. We have
found that the relatively large spectral width values ≥150 m/s observed
poleward of the boundary are produced by ionospheric irregularities with
lifetime τl≃10–25 ms, which is essentially independent of the
scale size. These irregularities are statistically co-located with low-energy
(~100 eV) electron precipitation, which may play a major role in
producing F-region turbulence above 75 MLAT via restructuring the ionospheric
plasma on time scales ~τl. |
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