Effects of mid-latitude geomagnetic storms on ionospheric Total Electron Content over South Africa

2016 ◽  
Vol 119 (1) ◽  
pp. 135-146
Author(s):  
V.P. van de Heyde ◽  
C.P. Price ◽  
D.M. Moeketsi
Keyword(s):  
South Africa ◽  
Total Electron Content ◽  
Geomagnetic Storms ◽  
Electron Content ◽  
Total Electron ◽  
Ionospheric Total Electron Content

scholarly journals Spatial and Temporal Variations of Polar Ionospheric Total Electron Content over Nearly Thirteen Years

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 540 ◽  
Author(s):  
Hui Xi ◽  
Hu Jiang ◽  
Jiachun An ◽  
Zemin Wang ◽  
Xueyong Xu ◽  
...  
Keyword(s):  
Solar Activity ◽  
Total Electron Content ◽  
Geomagnetic Storms ◽  
Weddell Sea ◽  
The Arctic ◽  
Electron Content ◽  
Spherical Cap ◽  
Total Electron ◽  
Ionospheric Total Electron Content ◽  
The Antarctic

It is of great significance for the global navigation satellite system (GNSS) service to detect the polar ionospheric total electron content (TEC) and its variations, particularly under disturbed ionosphere conditions, including different phases of solar activity, the polar day and night alternation, the Weddell Sea anomaly (WSA) as well as geomagnetic storms. In this paper, four different models are utilized to map the ionospheric TEC over the Arctic and Antarctic for about one solar cycle: the polynomial (POLY) model, the generalized trigonometric series function (GTSF) model, the spherical harmonic (SH) model, and the spherical cap harmonic (SCH) model. Compared to other models, the SCH model has the best performance with ±0.8 TECU of residual mean value and 1.5–3.5 TECU of root mean square error. The spatiotemporal distributions and variations of the polar ionospheric TEC are investigated and compared under different ionosphere conditions in the Arctic and Antarctic. The results show that the solar activity significantly affects the TEC variations. During polar days, the ionospheric TEC is more active than it is during polar nights. In polar days over the Antarctic, the maximum value of TEC always appears at night in the Antarctic Peninsula and Weddell Sea area affected by the WSA. In the same year, the ionospheric TEC of the Antarctic has a larger amplitude of annual variation than that of the TEC in the Arctic. In addition, the evolution of the ionization patch during a geomagnetic storm over the Antarctic can be clearly tracked employing the SCH model, which appears to be adequate for mapping the polar TEC, and provides a sound basis for further automatic identification of ionization patches.

Forecasting Ionospheric Total Electron Content During Geomagnetic Storms

2020 ◽  
Author(s):  
Rohaida Mat Akir ◽  
Siti Aminah Bahari ◽  
Mardina Abdullah ◽  
Mariyam Jamilah Homam ◽  
Kalaivani Chellapan ◽  
...  
Keyword(s):  
Total Electron Content ◽  
Geomagnetic Storms ◽  
Electron Content ◽  
Total Electron ◽  
Ionospheric Total Electron Content

scholarly journals Ionospheric Total Electron Content responses to HILDCAAs intervals

2019 ◽  
Author(s):  
Regia Pereira Silva ◽  
Clezio Marcos Denardini ◽  
Manilo Soares Marques ◽  
Laysa Cristina Araújo Resende ◽  
Juliano Moro ◽  
...  
Keyword(s):  
Solar Wind ◽  
Total Electron Content ◽  
High Speed ◽  
Geomagnetic Storms ◽  
Electron Content ◽  
Total Electron ◽  
Ionospheric Total Electron Content ◽  
Long Duration ◽  
Wind Velocities ◽  
Hourly Distribution

Abstract. The High-Intensity Long-Duration and Continuous AE Activities (HILDCAA) intervals are capable of causing a global disturbance in the terrestrial ionosphere. However, the ionospheric storms' behavior due to these geomagnetic activity forms is still not widely understood. In this study, we seek to comprise the HILDCAAs disturbance time effects in the Total Electron Content (TEC) values with respect to the quiet days' pattern analyzing local time and seasonal dependences, and the influences of the solar wind velocity to a sample of ten intervals occurred in 2015 and 2016 years. The main results showed that the hourly distribution of the disturbance TEC may vary substantially between one interval and another. Doing a comparative to geomagnetic storms, while the positive ionospheric storms are more pronounced in the winter, this season presents less geoeffectiveness or almost none to HILDCAA intervals. It was find an equinoctial anomaly, since the equinoxes represent more ionospheric TEC responses during HILDCAA intervals than the solstices. Regarding to the solar wind velocities, although HILDCAA intervals are associated to High Speed Streams, this association does not present a direct relation regards to TEC disturbances in low and equatorial latitudes.

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