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| Titel |
Aspect sensitivity measurements of polar mesosphere summer echoes using coherent radar imaging |
| VerfasserIn |
P. B. Chilson, T.-Y. Yu, R. D. Palmer, S. Kirkwood  |
| 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 ; 20, no. 2 ; Nr. 20, no. 2, S.213-223 |
| Datensatznummer |
250014357
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| Publikation (Nr.) |
 copernicus.org/angeo-20-213-2002.pdf |
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| Zusammenfassung |
The Esrange VHF radar (ESRAD),
located in northern Sweden (67.88° N, 21.10° E), has been used to investigate
polar mesosphere summer echoes (PMSE). During July and August of 1998, coherent
radar imaging (CRI) was used to study the dynamic evolution of PMSE with high
temporal and spatial resolution. A CRI analysis provides an estimate of the
angular brightness distribution within the radar’s probing volume. The
brightness distribution is directly related to the radar reflectivity.
Consequently, these data are used to investigate the aspect sensitivity of PMSE.
In addition to the CRI analysis, the full correlation analysis (FCA) is used to
derive estimates of the prevailing three-dimensional wind associated with the
observed PMSE. It is shown that regions within the PMSE with enhanced aspect
sensitivity have a correspondingly high signal-to-noise ratio (SNR). Although
this relationship has been investigated in the past, the present study allows
for an estimation of the aspect sensitivity independent of the assumed
scattering models and avoids the complications of comparing echo strengths from
vertical and off-vertical beams over large horizontal separations, as in the
Doppler Beam Swinging (DBS) method. Regions of enhanced aspect sensitivity were
additionally shown to correlate with the wave-perturbation induced downward
motions of air parcels embedded in the PMSE.
Key words. Ionosphere (polar
ionosphere) Meteorology and Atmospheric Dynamics (middle atmosphere dynamics)
Radio Science (Interferometry) |
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