Dynamical Complexity Response in Traveling Ionospheric Disturbances Across Eastern Africa Sector During Geomagnetic Storms Using Neural Network Entropy

• Published in: Journal of geophysical research. Space physics 2022-09, Vol.127 (9), p.n/a
• Main Authors: Oludehinwa, I. A., Velichko, A., Ogunsua, B. O., Olusola, O. I., Odeyemi, O. O., Njah, A. N., Ologun, O. T.
• Format: Article
• Language: English
• Subjects: Complexity; dynamical complexity; Entropy; Geomagnetic storms; Geomagnetism; Global positioning systems; GPS; Magnetic storms; neural network entropy (NNetEn); Neural networks; nonlinear dynamics; Northern Hemisphere; Reduction; Signatures; Southern Hemisphere; Storms; Total Electron Content; total electron content (TEC); Traveling ionospheric disturbances; traveling ionospheric disturbances (TIDs)
• ISSN: 2169-9380; 2169-9402
• DOI: 10.1029/2022JA030630

This paper examines the response of dynamical complexity in traveling ionospheric disturbances (TIDs) across Eastern Africa sector during major geomagnetic storms. Detrended total electron content derived from eight stations of Global Positioning System receivers across Eastern Africa was used to unveil the transient features of dynamical complexity response in TIDs. Neural network entropy (NNetEn) was applied to the detrended TEC time series data to capture the degree of dynamical complexity. The NNetEn track the distinct features associated with the occurrence of TIDs. The results show that as the signatures of TIDs begin to emerge, low values of NNetEn signifying reduction in the degree of dynamical complexity response were observed while high values of NNetEn were depicted as the signatures of TIDs subsides signifying increase in the dynamical complexity response. Reduction in dynamical complexity response associated with the occurrence of TIDs is more evident in the Southern Hemisphere compared to Northern Hemisphere. Furthermore, we found that the propagation of TIDs is more prominent at Equinoctial season compared to solstitial season. The latitudinal observation of NNetEn revealed higher degree of dynamical complexity response in ADIS and NEGE signifying that the development of TIDs is minimal in ADIS and NEGE. Finally, the reduction in dynamical complexity associated with the occurrence of TIDs were obvious during all the phases of geomagnetic storms. In particular, the dynamical complexity response at initial and recovery phases of geomagnetic storm depicts more TIDs features. Key Points As the signatures of traveling ionospheric disturbances (TIDs) begin to emerge, the dynamical complexity reduces while dynamical complexity increases as TIDs signatures subsides Dynamical complexity associated with TIDs features is more evident in the Southern Hemisphere compared to the Northern Hemisphere The propagation of TIDs is more prominent at Equinoctial season compared to the solstitial season