Dynamical complexity response in Traveling Ionospheric Disturbances
across Eastern Africa sector during geomagnetic storms using Neural
Network Entropy.
Abstract
This paper examines the response of dynamical complexity in Traveling
Ionospheric Disturbances (TIDs) across Eastern Africa sector during 2015
major geomagnetic storms. Detrended Total Electron Content (DTEC)
derived from Eight stations of Global Positioning System (GPS) 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. As the signatures of TIDs begin
to emerge, we found low values of NNetEn signifying reduction in the
degree of dynamical complexity response as TIDs occur while high values
of NNetEn were depicted as the signatures of TIDs subsides signifying
increase in the dynamical complexity response, as the TIDs signatures
begin to subsides. Also, we found that the response of dynamical
complexity associated with TIDs features expands from the Southern
Hemisphere and diminishes at the Northern Hemisphere. Reduction in
dynamical complexity response associated with the occurrence of TIDs is
more evident in the Southern Hemisphere compared to Northern Hemisphere
indicating that the propagation of TIDs is more prominent in the
Southern 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.