 |
| Titel |
Low-latitude equinoctial spread-F occurrence at different longitude sectors under low solar activity |
| VerfasserIn |
M. Pezzopane, E. Zuccheretti, P. Abadi, A. J. Abreu, R. Jesus, P. R. Fagundes, P. Supnithi, S. Rungraengwajiake, T. Nagatsuma, T. Tsugawa, M. A. Cabrera, R. G. Ezquer |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
0992-7689
|
| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 31, no. 2 ; Nr. 31, no. 2 (2013-02-05), S.153-162 |
| Datensatznummer |
250017746
|
| Publikation (Nr.) |
 copernicus.org/angeo-31-153-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
| We present the results of a comparative study of spread-F signatures over
five low-latitude sites: Chiangmai (CGM; 18.8° N, 98.9° E,
mag. Lat. 8.8° N), Thailand; Tanjungsari (TNJ; 6.9° S,
107.6° E, mag. Lat. 16.9° S), Indonesia; Palmas (PAL;
10.2° S, 311.8° E, mag. Lat. 0.9° S) and
São José Dos Campos (SJC; 23.2° S, 314.1° E,
mag. Lat. 14.0° S), Brazil; and Tucumán (TUC; 26.9° S,
294.6° E, mag. Lat. 16.8° S), Argentina. The
investigation was based on simultaneous ionograms recorded by an FMCW (frequency-modulated continuous-wave) at
CGM, an IPS-71 (digital ionosonde from KEL aerospace) at TNJ, a CADI (Canadian Advanced Digital Ionosonde) at PAL and SJC, and an AIS-INGV
(Advanced Ionospheric Sounder – Istituto Nazionale di Geofisica e Vulcanologia) at TUC, during
the equinoctial periods March–April (R12 = 2.0 and R12 = 2.2) and
September–October (R12 = 6.1 and R12 = 7.0) 2009, for very low
solar activity. Spread-F signatures were categorized into two types: the
range spread-F (RSF) and the frequency spread-F (FSF). The study confirms
that the dynamics and the physical processes responsible for these phenomena
are actually complicated. In fact, the features that arise from the
investigation are different, depending on both the longitude sector and on
the hemisphere. For instance, TUC, under the southern crest of the ionospheric equatorial ionization anomaly (EIA), shows a predominance of
RSF signatures, while both SJC, under the southern crest of EIA but in a
different longitude sector, and CGM, under the northern crest of EIA, show a
predominance of FSF signatures. Moreover, the spread-F occurrence over the
longitude sector that includes CGM and TNJ is significantly lower than the
spread-F occurrence over the longitude sector of PAL, SJC, and TUC. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|