In this paper, Vertical Total Electron Content (VTEC) data derived from dual-frequency GPS measurements obtained at two ground stations were used to study the variability of the equatorial ionization anomaly (EIA). The present study only focuses on analysis of the crest-to-trough TEC ratio (TEC-CTR) in the southern crest region. Data used in this study was obtained for the high solar activity year 2012. MAL2 station (Geomag Lat. -12.4°S, Geomag Long. 111.9°E) was considered for the southern crest region whereas ADIS station (Geomag Lat. 0.2°N, Geomag Long. 110.5°E) was considered for the trough region. Diurnal and seasonal variations as well as the dependency of TEC-CTR on solar activity levels were investigated in the present study. The results showed that the diurnal variation pattern of TEC-CTR is characterized by two remarkable peak values, one occurring in the post‐midnight hours around 02: 00-03: 00 UT (05: 00-06: 00 LT) and the second (highest) peak occurred in the post-sunset hours around 18: 00-20: 00 UT (21: 00-23: 00 LT). Seasonal TEC-CTR variations showed a semi-annual variation pattern, with maximum peak values occurring in the equinoctial months. TEC-CTR also revealed an existence of winter anomaly in this region, with higher values of TEC-CTR in the winter solstice than summer solstice. TEC-CTR in the daytime post-noon hours; between 01: 00-04: 00 UT (04: 00-07: 00 LT) does not vary much with the solar activity; however, TEC-CTR in the post-sunset hours; between 16: 00-20: 00 UT (19: 00-23: 00 LT) shows a clear dependence on the solar activity, with its values increasing with solar activity.
| Published in | International Journal of Astrophysics and Space Science (Volume 4, Issue 1) |
| DOI | 10.11648/j.ijass.20160401.12 |
| Page(s) | 12-20 |
| Creative Commons |
This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited. |
| Copyright |
Copyright © The Author(s), 2016. Published by Science Publishing Group |
Total Electron Content (TEC), Equatorial Ionization Anomaly (EIA), GPS Measurements, Solar Activity
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APA Style
Bosco Oryema, Edward Jurua, Nicolausi Ssebiyonga. (2016). Variations of Crest-to-Trough TEC Ratio of the East African Equatorial Anomaly Region. International Journal of Astrophysics and Space Science, 4(1), 12-20. https://doi.org/10.11648/j.ijass.20160401.12
ACS Style
Bosco Oryema; Edward Jurua; Nicolausi Ssebiyonga. Variations of Crest-to-Trough TEC Ratio of the East African Equatorial Anomaly Region. Int. J. Astrophys. Space Sci. 2016, 4(1), 12-20. doi: 10.11648/j.ijass.20160401.12
AMA Style
Bosco Oryema, Edward Jurua, Nicolausi Ssebiyonga. Variations of Crest-to-Trough TEC Ratio of the East African Equatorial Anomaly Region. Int J Astrophys Space Sci. 2016;4(1):12-20. doi: 10.11648/j.ijass.20160401.12
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Download@article{10.11648/j.ijass.20160401.12,
author = {Bosco Oryema and Edward Jurua and Nicolausi Ssebiyonga},
title = {Variations of Crest-to-Trough TEC Ratio of the East African Equatorial Anomaly Region},
journal = {International Journal of Astrophysics and Space Science},
volume = {4},
number = {1},
pages = {12-20},
doi = {10.11648/j.ijass.20160401.12},
url = {https://doi.org/10.11648/j.ijass.20160401.12},
eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ijass.20160401.12},
abstract = {In this paper, Vertical Total Electron Content (VTEC) data derived from dual-frequency GPS measurements obtained at two ground stations were used to study the variability of the equatorial ionization anomaly (EIA). The present study only focuses on analysis of the crest-to-trough TEC ratio (TEC-CTR) in the southern crest region. Data used in this study was obtained for the high solar activity year 2012. MAL2 station (Geomag Lat. -12.4°S, Geomag Long. 111.9°E) was considered for the southern crest region whereas ADIS station (Geomag Lat. 0.2°N, Geomag Long. 110.5°E) was considered for the trough region. Diurnal and seasonal variations as well as the dependency of TEC-CTR on solar activity levels were investigated in the present study. The results showed that the diurnal variation pattern of TEC-CTR is characterized by two remarkable peak values, one occurring in the post‐midnight hours around 02: 00-03: 00 UT (05: 00-06: 00 LT) and the second (highest) peak occurred in the post-sunset hours around 18: 00-20: 00 UT (21: 00-23: 00 LT). Seasonal TEC-CTR variations showed a semi-annual variation pattern, with maximum peak values occurring in the equinoctial months. TEC-CTR also revealed an existence of winter anomaly in this region, with higher values of TEC-CTR in the winter solstice than summer solstice. TEC-CTR in the daytime post-noon hours; between 01: 00-04: 00 UT (04: 00-07: 00 LT) does not vary much with the solar activity; however, TEC-CTR in the post-sunset hours; between 16: 00-20: 00 UT (19: 00-23: 00 LT) shows a clear dependence on the solar activity, with its values increasing with solar activity.},
year = {2016}
}
TY - JOUR T1 - Variations of Crest-to-Trough TEC Ratio of the East African Equatorial Anomaly Region AU - Bosco Oryema AU - Edward Jurua AU - Nicolausi Ssebiyonga Y1 - 2016/03/02 PY - 2016 N1 - https://doi.org/10.11648/j.ijass.20160401.12 DO - 10.11648/j.ijass.20160401.12 T2 - International Journal of Astrophysics and Space Science JF - International Journal of Astrophysics and Space Science JO - International Journal of Astrophysics and Space Science SP - 12 EP - 20 PB - Science Publishing Group SN - 2376-7022 UR - https://doi.org/10.11648/j.ijass.20160401.12 AB - In this paper, Vertical Total Electron Content (VTEC) data derived from dual-frequency GPS measurements obtained at two ground stations were used to study the variability of the equatorial ionization anomaly (EIA). The present study only focuses on analysis of the crest-to-trough TEC ratio (TEC-CTR) in the southern crest region. Data used in this study was obtained for the high solar activity year 2012. MAL2 station (Geomag Lat. -12.4°S, Geomag Long. 111.9°E) was considered for the southern crest region whereas ADIS station (Geomag Lat. 0.2°N, Geomag Long. 110.5°E) was considered for the trough region. Diurnal and seasonal variations as well as the dependency of TEC-CTR on solar activity levels were investigated in the present study. The results showed that the diurnal variation pattern of TEC-CTR is characterized by two remarkable peak values, one occurring in the post‐midnight hours around 02: 00-03: 00 UT (05: 00-06: 00 LT) and the second (highest) peak occurred in the post-sunset hours around 18: 00-20: 00 UT (21: 00-23: 00 LT). Seasonal TEC-CTR variations showed a semi-annual variation pattern, with maximum peak values occurring in the equinoctial months. TEC-CTR also revealed an existence of winter anomaly in this region, with higher values of TEC-CTR in the winter solstice than summer solstice. TEC-CTR in the daytime post-noon hours; between 01: 00-04: 00 UT (04: 00-07: 00 LT) does not vary much with the solar activity; however, TEC-CTR in the post-sunset hours; between 16: 00-20: 00 UT (19: 00-23: 00 LT) shows a clear dependence on the solar activity, with its values increasing with solar activity. VL - 4 IS - 1 ER -
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