Skip to main content
Log in

Assessment of long-term impact of solar activity on the ionosphere over an African equatorial GNSS station

  • Research
  • Published:
Earth Science Informatics Aims and scope Submit manuscript

Abstract

The level of solar activity and its influence on ionospheric variability has received a focal interest among the ionospheric community. This paper examines the impact of long-term solar activity on the ionosphere over an African equatorial global navigation satellite system (GNSS) station based on a large database of solar and ionospheric datasets. The ionospheric total electron content (TEC) periodic variations, climatology and its relation to solar activity are investigated through wavelet analyses. It is observed that the magnitude and intensity of TEC fluctuations measured by GNSS receivers vary substantially with solar radiation intensity. To probe the processes accountable for the TEC periodicities in the region, the wavelet analysis is undertaken by considering solar indices (solar radio flux and sunspot number) and observed TEC values. The results show a clear strong periodicity of 27 days in the ionospheric TEC, sunspots and F10.7 solar flux power spectra, associated with the sun’s 27 days rotation period. The ultraviolet ray intensity and solar ionization were lower during the solar maximum period (2013 to 2014) of solar cycle 24 compared to the solar maximum period (2001 to 2002) of solar cycle 23, which is the key factor for driving the decreasing trend in TEC between 1999 and 2017. The ionospheric and solar climatology analysis indicates that ionospheric TEC behaviour could be a good indicator of long-term solar activity trend. A large mass of Africa lies within the equatorial and low latitudes making the ionosphere over the region being highly susceptible to low latitude electrodynamics. Results from this study would support the concerted efforts towards developing a reliable regional ionospheric forecasting model for technological applications relying on spaced-based navigation and satellite services.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7

Similar content being viewed by others

Data availability

The ionospheric-solar effect analysis was done by considering the corresponding F10.7 and sunspot data downloaded from the NASA-OMNI website (https://omniweb.gsfc.nasa.gov/form/dx1.html). The raw GPS datasets are freely available at http://afrefdata.org/. The Global Ionospheric Maps and DCB files are freely available at ftp://ftp.unibe.ch/aiub. The GPS-TEC dataset at the GridPoint (134.05 E and 34.95 N), generated during and/or analysed during the current study are available from the corresponding author on reasonable request.

References

Download references

Acknowledgments

The authors wish to acknowledge the Regional Centre for Mapping of Resources for Development (RCMRD) for making available the African Geodetic Reference Frame (AFREF) recorded GNSS data, the International GNSS Service (IGS) and the Centre for Orbit Determination in Europe, University of Berne (CODE) for providing the Global Ionospheric Maps, precise ephemeris, DCB data, and the Kyoto World Data Center for the solar indices files.

Funding

The authors declare that no funds, or grants, or other support were received during the preparation of this manuscript.

Author information

Authors and Affiliations

Authors

Contributions

Mefe Moses and Sampad Kumar Panda designed the study, implemented the methodology and drafted the manuscript. Joseph D. Dodo, Lazarus M. Ojigi, and Kola Lawal supervised the study and contributed to the overall study design and writing of the manuscript. All authors participated in formulating the idea and in discussing the proposed approach and results. All authors read and approved the final manuscript.

Corresponding author

Correspondence to Mefe Moses.

Ethics declarations

Conflict of interest

The authors declare no conflict of interest.

Additional information

Communicated by: H. Babaie

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Springer Nature or its licensor holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Moses, M., Panda, S.K., Dodo, J.D. et al. Assessment of long-term impact of solar activity on the ionosphere over an African equatorial GNSS station. Earth Sci Inform 15, 2109–2117 (2022). https://doi.org/10.1007/s12145-022-00863-y

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s12145-022-00863-y

Keywords

Navigation