University of Oulu

Moges, S. T., Giday, N. M., Chekole, D. A., Ulich, T., & Sherstyukov, R. O. (2022). Storm-time observations of traveling ionospheric disturbances and ionospheric irregularities in East Africa. Radio Science, 57, e2022RS007426.

Storm-time observations of traveling ionospheric disturbances and ionospheric irregularities in East Africa

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Author: Moges, Samson T.1,2; Giday, Nigussie Mezgebe2; Chekole, Daniel Atnafu2;
Organizations: 1Sodankylä Geophysical Observatory, University of Oulu, Sodankylä, Finland
2Department of Space Science Applications and Research Development, Ethiopian Space Science and Technology Institute, Addis Ababa, Ethiopia
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 7 MB)
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Language: English
Published: American Geophysical Union, 2022
Publish Date: 2022-09-27


In this paper equatorward propagating large scale traveling ionospheric disturbance (LSTID) on 17 March 2015 were investigated using the Statistical Angle-of-Arrival and Doppler Method for GPS (SADM-GPS) radio interferometry technique in data-scarce East Africa. To apply the SADM-GPS method, 5 GPS arrays each with 3 GPS receivers arranged in a triangular geometry were used. Our results show that during 15:00–18:00 UT on 17 March, TIDs with mean horizontal velocities between 161.9 and 464.4 m/s were observed. Using the wavelet analysis, the periods of TIDs in a range of 51–69 min that qualify to LSTIDs were revealed. The peak-to-peak phase shift of detrended total electron content (TEC) over latitudes in this study confirms the equatorward TID propagation, which was obtained by the SADM-GPS technique. A pair of magnetometers were used to infer E × B drift and an adequate agreement was found with Swarm satellites derived plasma density that enabled us to explain the behaviour of ionospheric irregularity during the main phase of the geomagnetic storm. Moreover, significant TEC enhancement (reaching ∼20%–105%) were captured by GPS arrays during the period of TID propagation. Nevertheless, the rate of change of TEC (ROT) and ROT index (ROTI) show wavy structures that reflect TID effects over ionospheric modulations during the post noon to evening hours of 17 March 2015.

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Series: Radio science
ISSN: 0048-6604
ISSN-E: 1944-799X
ISSN-L: 0048-6604
Volume: 57
Issue: 8
Pages: 1 - 17
DOI: 10.1029/2022rs007426
Type of Publication: A1 Journal article – refereed
Field of Science: 115 Astronomy and space science
Dataset Reference: Magnetometer data were obtained from INTERMAGNET (TAM station) and AMBER (CMRN station) arrays at ( and ( respectively. We downloaded the total electron content (TEC) data for stations considered from and further processed to obtain their VTEC. Furthermore, the plasma density (Ne) profile measured by the Langmuir Probe on each Swarm satellite is obtained by switching into (Advanced/Plasma_data/Provisional_Plasma_dataset/Langmuir_Probes_Data/) after browsing Besides, SYM-H index and the ACE provided (Bz component of IMF, proton density and derived parameter Ey) are downloaded from
Copyright information: © 2022 The Authors. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.