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| Titel |
Low-latitude scintillation occurrences around the equatorial anomaly crest over Indonesia |
| VerfasserIn |
P. Abadi, S. Saito, W. Srigutomo |
| 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 ; 32, no. 1 ; Nr. 32, no. 1 (2014-01-16), S.7-17 |
| Datensatznummer |
250121016
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| Publikation (Nr.) |
 copernicus.org/angeo-32-7-2014.pdf |
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| Zusammenfassung |
| We investigated low-latitude ionospheric scintillation in Indonesia using two
GPS receivers installed at Bandung (107.6° E, 6.9° S;
magnetic latitude 17.5° S) and Pontianak (109.3° E,
0.02° S; magnetic latitude 8.9° S). This study aimed to
characterise climatological and directional ionospheric scintillation
occurrences, which are useful not only for the physics of ionospheric
irregularities but also for practical use in GNSS (global navigation
satellite system)-based navigation. We used the deployed instrument's
amplitude scintillation (S4 index) data from 2009, 2010, and 2011; the yearly
SSN (sunspot-smoothed numbers) were 3.1, 16.5, and 55.9, respectively. In
summary, (1) scintillation occurrences in the post-sunset period
(18:00–01:00 LT) during equinox months (plasma bubble season) at the two
sites can be ascribed to the plasma bubble; (2) using directional analyses of
the two sites, we found that the distribution of scintillation occurrences is
generally concentrated between the two sites, indicating the average location
of the EIA (equatorial ionisation anomaly) crest; (3) scintillation
occurrence enhancements for the two sites in field-aligned directions are
herein reported for the first time by ground-based observation in a
low-latitude region; (4) distribution of scintillation occurrences at
Pontianak are concentrated in the southern sky, especially in the southwest
direction, which is very likely associated with the plasma bubble tilted
westward with increasing latitude; and (5) scintillation occurrence in the
post-midnight period in the non-plasma-bubble season is the most intriguing
variable occurring between the two sites (i.e. post-midnight scintillations
are observed more at Bandung than Pontianak). Most of the post-midnight
scintillations observed at Bandung are concentrated in the northern sky, with
low elevation angles. This might be due to the amplitude of
irregularities in certain directions, which may be effectively
enhanced by background density enhancement by the EIA and because
satellite–receiver paths are longer in the EIA crest region and in a
field-aligned direction. |
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