| Full text | |
| Author(s): |
de Abreu, Alessandro Jose
;
Martin, Inacio Malmonge
;
de Jesus, Rodolfo
;
Alves Bolzan, Mauricio Jose
;
Venkatesh, Kavutarapu
;
Fagundes, Paulo Roberto
;
Alves, Mauro Angelo
;
Gende, Mauricio
;
Kumar, Sanjay
Total Authors: 9
|
| Document type: | Journal article |
| Source: | ANNALS OF GEOPHYSICS; v. 60, n. 3 2017. |
| Web of Science Citations: | 6 |
| Abstract | |
The total electron content (TEC) derived from two Global Positioning System (GPS) receivers localized at Palmas (PAL, 10.2 degrees S, 48.2 degrees W, dip latitude 5.5 degrees S), near equatorial region, and Sao Jose dos Campos (SJC, 23.2 degrees S, 45.9 degrees W, dip latitude 17.6 degrees S), under the southern crest of the equatorial ionization anomaly (EIA), in the Brazilian sector are used in this paper. TEC from the latest available IRI-2012 model at the same locations is also used. A comparative study between GPS-TEC and the IRI-2012 model is analyzed during the deep low solar activity period of 2009 in the unusual solar cycle 23. The measurements and the modeled data show that the IRI-TEC model gives the better estimates of the GPS-TEC during the nighttime from January to December months at PAL and SJC. The IRI-TEC model shows larger differences from the GPS-TEC in the afternoon hours, mainly at SJC. These discrepancies observed at SJC in the afternoon hours for all months are possibly due to the dynamics of EIA in consequence of the equatorial fountain effect. At PAL and SJC, oscillations of GPS-TEC with periods around 16 days in April and periods around 27-32 days between September and December possibly are noticed which could be related to a modulation of the semidiurnal tide and Sun's rotation, respectively. Also, oscillations with periods around 2-4 and 5-10 days from January to December are observed at PAL and SJC, possibly associated with the propagation of planetary waves. (AU) | |
| FAPESP's process: | 12/08445-9 - Study of day-to-day variability of the mesosphere, thermosphere and ionosphere at low latitude and equatorial region, during the solar cycle 24 |
| Grantee: | Paulo Roberto Fagundes |
| Support Opportunities: | Research Projects - Thematic Grants |