| Full text | |
| Author(s): |
Total Authors: 3
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| Affiliation: | [1] Univ Vale Paraiba, IP&D, Lab Fis & Astron, BR-12244000 Sao Paulo - Brazil
[2] Inst Nacl Pesquisas Espaciais, Div Aeron, BR-12227010 Sao Paulo - Brazil
Total Affiliations: 2
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| Document type: | Review article |
| Source: | SURVEYS IN GEOPHYSICS; v. 34, n. 2, p. 233-251, MAR 2013. |
| Web of Science Citations: | 9 |
| Abstract | |
This paper reports differences in the occurrence statistics of global positioning system (GPS) L-band scintillations at observational sites located in the inner regions of the northern and southern crests of the equatorial ionization anomaly. Ground-based GPS data acquired at the closed magnetically aligned stations of Manaus (3.1A degrees S; 59.9A degrees W; dip lat. 6.2A degrees N) and Cuiaba (15.5A degrees S; 56.1A degrees W; dip. lat. 6.2A degrees S), Brazil, from December 2001 to February 2007 are used in the analysis. The drift dynamics of Fresnel-scale ionospheric irregularities at the southern station of Cuiaba are also investigated. Only geomagnetically quiet days with the sum of daily Kp < 24 were used in the analysis statistics and in the irregularity drift studies. The results reveal a clear dependence of the scintillation occurrence with the solar activity, but there exists an asymmetry in the percentage of scintillation occurrence between the two stations throughout the period analyzed. The nocturnal occurrence of the scintillations over Cuiaba is predominantly larger than over Manaus, but this scenario seems to change with the decline in the solar activity (mainly during local post-midnight hours). A broad minimum and maximum in the scintillation occurrence appears to occur over both the stations, respectively, during the June solstice (winter) and December solstice (summer) months. The dynamics of the Fresnel-scale irregularities, as investigated from the estimations of the mean zonal drift velocities, reveals that the amplitude of the eastward drifts tends to reduce with the decline in the solar activity. The magnitude of the zonal drift velocities during the December solstice months is larger than during the equinoxes, with the differences being more pronounced at solar maximum years. Other relevant aspects of the observations, with complementary data from a low-latitude ionospheric model, are highlighted and discussed. (AU) | |
| FAPESP's process: | 10/03545-0 - Study of coupling between mesosphere-ionosphere due to gravity waves using numerical modeling. |
| Grantee: | Alan de Andrade Monteiro |
| Support Opportunities: | Scholarships in Brazil - Master |
| FAPESP's process: | 08/04892-5 - Study of the temporal and spatial dependence between plasma irregularities and total electron content as a basis to the development of a ionospheric scintillation model: simultaneous investigation of ionospheric radiotomography |
| Grantee: | Marcio Tadeu de Assis Honorato Muella |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |