Articles | Volume 32, issue 3
https://doi.org/10.5194/npg-32-225-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/npg-32-225-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
14 Jul 2025
Research article |
| 14 Jul 2025
| 14 Jul 2025
Ionospheric chaos in the solar quiet current due to sudden stratospheric warming events across the European and African sectors
Irewola Aaron Oludehinwa
CORRESPONDING AUTHOR
Department of Physics, Caleb University, Lagos, Nigeria
Department of Physics, University of Lagos, Lagos, Nigeria
Andrei Velichko
Institute of Physics and Technology, Petrozavodsk State University, 185910 Petrozavodsk, Russia
Olasunkanmi Isaac Olusola
Department of Physics, University of Lagos, Lagos, Nigeria
Olawale Segun Bolaji
Institute of Physics and Technology, Petrozavodsk State University, 185910 Petrozavodsk, Russia
Department of Physics, University of Tasmania, Hobart, Australia
Norbert Marwan
Research Department of Complexity Science, Potsdam Institute for Climate Impact Research (PIK), Member of the Leibniz Association, 14412 Potsdam, Germany
Babalola Olasupo Ogunsua
Key Laboratory for Middle Atmospheric and Global Environment Observation (LAGEO), Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences, Beijing, China
Department of Physics, Federal University of Technology, Akure, Nigeria
Abdullahi Ndzi Njah
Department of Physics, University of Lagos, Lagos, Nigeria
Timothy Oluwaseyi Ologun
Department of Physics, Federal University of Technology, Akure, Nigeria
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B. O. Ogunsua, J. A. Laoye, I. A. Fuwape, and A. B. Rabiu
Nonlin. Processes Geophys., 21, 127–142, https://doi.org/10.5194/npg-21-127-2014, https://doi.org/10.5194/npg-21-127-2014, 2014
N. Itoh and N. Marwan
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Related subject area
Subject: Bifurcation, dynamical systems, chaos, phase transition, nonlinear waves, pattern formation | Topic: Ionosphere, magnetosphere, planetary science, solar science | Techniques: Big data and artificial intelligence
Magnetospheric chaos and dynamical complexity response during storm time disturbance
Irewola Aaron Oludehinwa, Olasunkanmi Isaac Olusola, Olawale Segun Bolaji, Olumide Olayinka Odeyemi, and Abdullahi Ndzi Njah
Nonlin. Processes Geophys., 28, 257–270, https://doi.org/10.5194/npg-28-257-2021, https://doi.org/10.5194/npg-28-257-2021, 2021
Short summary
Short summary
The MLE and ApEn values of the Dst indicate that chaotic and dynamical complexity responses are high during minor geomagnetic storms, reduce at moderate geomagnetic storms and decline further during major geomagnetic storms.
However, the MLE and ApEn values obtained from solar wind electric field (VBs) indicate that chaotic and dynamical complexity responses are high with no significant difference between the periods that are associated with minor, moderate and major geomagnetic storms.
Cited articles
Azami, H., Li, P., Arnold, S. E., Escudero, J., and Humeau-Heurtier, A.: Fuzzy entropy metrics for the analysis of biomedical signals: Assessment and comparison, IEEE Access, 7, 104833–104847, https://doi.org/10.1109/ACCESS.2019.2930625, 2019.
Baldwin, M. P., Ayarzagüena, B., Birner, T., Butchart, N., Butler, A. H., Charlton-Perez, A. J., Domeisen, D. I. V., Garfinkel, C. I., Garny, H., Gerber, E. P., Hegglin, M. I., Langematz, U., and Pedatella, N. M.: Sudden Stratospheric Warmings, Rev. Geophys., 59, 1–37, https://doi.org/10.1029/2020RG000708, 2021.
Barton, C. E. and Tarlowski, C. Z.: Geomagnetic, geocentric, and geodetic coordinate transformations, Comput. Geosci., 17, 669–678, https://doi.org/10.1016/0098-3004(91)90038-F, 1991.
Bolaji, O. S., Oyeyemi, E. O., Owolabi, O. P., Yamazaki, Y., Rabiu, A. B., Okoh, D., Fujimoto, A., Amory-Mazaudier, C., Seemala, G. K., Yoshikawa, A., and Onanuga, O. K.: Solar quiet current response in the African sector due to a 2009 sudden stratospheric warming event, J. Geophys. Res.-Space, 121, 8055–8065, https://doi.org/10.1002/2016JA022857, 2016a.
Bolaji, O. S., Oyeyemi, E. O., Owolabi, O. P., Yamazaki, Y., Rabiu, A. B., Okoh, D., Fujimoto, A., Amory-Mazaudier, C., Seemala, G. K., Yoshikawa, A., and Onanuga, O. K.: Solar quiet current response in the African sector due to a 2009 sudden stratospheric warming event, J. Geophys. Res.-Space, 121, 8055–8065, https://doi.org/10.1002/2016JA022857, 2016b.
Butler, A. H., Seidel, D. J., Hardiman, S. C., Butchart, N., Birner, T., and Match, A.: Defining sudden stratospheric warmings, B. Am. Meteorol. Soc., 96, 1913–1928, https://doi.org/10.1175/BAMS-D-13-00173.1, 2015.
Chau, J. L., Goncharenko, L. P., Fejer, B. G., and Liu, H. L.: Equatorial and low latitude ionospheric effects during sudden stratospheric warming events: Ionospheric effects during SSW events, Space Sci. Rev., 168, 385–417, https://doi.org/10.1007/s11214-011-9797-5, 2012.
Chen, W., Wang, Z., Xie, H., and Yu, W.: Characterization of Surface EMG Signal Based on Fuzzy Entropy, IEEE Trans. Neur. Sys. Reh., 15, 266–272, https://doi.org/10.1109/TNSRE.2007.897025, 2007.
Conejero, J. A., Velichko, A., Garibo-i-Orts, Ò., Izotov, Y., and Pham, V. T.: Exploring the Entropy-Based Classification of Time Series Using Visibility Graphs from Chaotic Maps, Mathematics, 12, 938, https://doi.org/10.3390/math12070938, 2024.
Dass, B., Tomar, V. P., and Kumar, K.: Fuzzy entropy with order and degree for intuitionistic fuzzy set, AIP Conf. Proc., 1, 2142, https://doi.org/10.1063/1.5122619, 2019.
EntropyHub: An Open-Source Toolkit for Entropic Time Series Analysis, (version 0.2), https://www.entropyhub.xyz/, last access: 27 February 2024.
Fejer, B. G., Tracy, B. D., Olson, M. E., and Chau, J. L.: Enhanced lunar semidiurnal equatorial vertical plasma drifts during sudden stratospheric warmings, Geophys. Res. Lett., 38, L21104, https://doi.org/10.1029/2011GL049788, 2011.
GFZ: Kp Index – Kp-Index, GFZ [data set], https://kp.gfz.de/en/data#c222, last access: 11 July 2025.
Gonçalves, B. A., Carpi, L., Rosso, O. A., and Ravetti, M. G.: Time series characterization via horizontal visibility graph and Information Theory, Phys. A Stat. Mech. Appl., 464, 93–102, https://doi.org/10.1016/j.physa.2016.07.063, 2016.
Goncharenko, L. P., Chau, J. L., Liu, H.-L., and Coster, A. J.: Unexpected connections between the stratosphere and ionosphere, Geophys. Res. Lett., 37, L10101, https://doi.org/10.1029/2010GL043125, 2010.
Goncharenko, L. P., Coster, A. J., Plumb, R. A., and Domeisen, D. I. V: The potential role of stratospheric ozone in the stratosphere-ionosphere coupling during stratospheric warmings, Geophys. Res. Lett., 39, L08101, https://doi.org/10.1029/2012GL051261, 2012.
Goncharenko, L. P., Harvey, V. L., Liu, H., and Pedatella, N. M.: Sudden Stratospheric Warming Impacts on the Ionosphere-Thermosphere System: A Review of Recent Progress, Geophysical Monograph Series, Wiley, 369–400, https://doi.org/10.1002/9781119815617.ch16, 2021.
Intermagnet: International Real-time Magnetic Observatory Network, Intermagnet [data set], https://imag-data.bgs.ac.uk/GIN_V1/GINForms2, last access: 11 July 2025.
Ishikawa, A. and Mieno, H.: The fuzzy entropy concept and its application, Fuzzy Set. Syst., 2, 113–123, https://doi.org/10.1016/0165-0114(79)90020-4, 1979.
Klimenko, M. V., Bessarab, F. S., Sukhodolov, T. V., Klimenko, V. V., Koren'kov, Y. N., Zakharenkova, I. E., Chirik, N. V., Vasil'ev, P. A., Kulyamin, D. V., Shmidt, K., Funke, B., and Rozanov, E. V.: Ionospheric Effects of the Sudden Stratospheric Warming in 2009: Results of Simulation with the First Version of the EAGLE Model, Russ. J. Phys. Chem. B, 12, 760–770, https://doi.org/10.1134/S1990793118040103, 2018.
Klimenko, M. V., Klimenko, V. V., Bessarab, F. S., Sukhodolov, T. V., Vasilev, P. A., Karpov, I. V., Korenkov, Y. N., Zakharenkova, I. E., Funke, B., and Rozanov, E. V.: Identification of the mechanisms responsible for anomalies in the tropical lower thermosphere/ionosphere caused by the January 2009 sudden stratospheric warming, J. Sp. Weather Sp. Clim., 9, A39, https://doi.org/10.1051/swsc/2019037, 2019.
Li, C., Li, Z., Guan, L., Qi, P., Si, J., and Hao, B.: Measuring the complexity of chaotic time series by fuzzy entropy, ACM Int. Conf. Proceeding Ser., 17, F1305, https://doi.org/10.1145/3102304.3102320, 2017.
Liu, H.-L., Wang, W., Richmond, A. D., and Roble, R. G.: Ionospheric variability due to planetary waves and tides for solar minimum conditions, J. Geophys. Res.-Space, 115, A00G01, https://doi.org/10.1029/2009JA015188, 2010.
Liu, N., Jin, Y., He, Z., Yu, J., Li, K., and Cui, J.: Simultaneous Evolutions of Inner Magnetospheric Plasmaspheric Hiss and EMIC Waves Under the Influence of a Heliospheric Plasma Sheet, Geophys. Res. Lett., 49, e2022GL098798, https://doi.org/10.1029/2022GL098798, 2022.
Luque, B., Lacasa, L., Ballesteros, F., and Luque, J.: Horizontal visibility graphs: Exact results for random time series, Phys. Rev. E, 80, 46103, https://doi.org/10.1103/PhysRevE.80.046103, 2009.
MAGDAS: MAGDAS HOMEPAGE, MAGDAS [data set], http://magdas2.serc.kyushu-u.ac.jp/, last access: 18 November 2023.
Maute, A., Hagan, M. E., Richmond, A. D., and Roble, R. G.: TIME-GCM study of the ionospheric equatorial vertical drift changes during the 2006 stratospheric sudden warming, J. Geophys. Res.-Space, 119, 1287–1305, https://doi.org/10.1002/2013JA019490, 2014.
NASA: OMNIWeb Data Explorer, NASA [data set], https://omniweb.gsfc.nasa.gov/form/dx1.html, last access: 12 February 2024.
NOAA: Climate Plotting and Analysis Tools: NOAA Physical Sciences Laboratory, NOAA [data set], https://psl.noaa.gov/data/composites/day/, last access: 11 July 2025.
O'Pella, J.: Horizontal visibility graphs are uniquely determined by their directed degree sequence, Phys. A Stat. Mech. Appl., 536, 120923, https://doi.org/10.1016/j.physa.2019.04.159, 2019.
Pedatella, N. M., Liu, H.-L., Sassi, F., Lei, J., Chau, J. L., and Zhang, X.: Ionosphere variability during the 2009 SSW: Influence of the lunar semidiurnal tide and mechanisms producing electron density variability, J. Geophys. Res.-Space, 119, 3828–3843, https://doi.org/10.1002/2014JA019849, 2014.
Salminen, A., Asikainen, T., Maliniemi, V., and Mursula, K.: Dependence of Sudden Stratospheric Warmings on Internal and External Drivers, Geophys. Res. Lett., 47, e2019GL086444, https://doi.org/10.1029/2019GL086444, 2020.
Siddiqui, T. A., Maute, A., Pedatella, N., Yamazaki, Y., Lühr, H., and Stolle, C.: On the variability of the semidiurnal solar and lunar tides of the equatorial electrojet during sudden stratospheric warmings, Ann. Geophys., 36, 1545–1562, https://doi.org/10.5194/angeo-36-1545-2018, 2018.
Tsurutani, B. T., Hajra, R., Tanimori, T., Takada, A., Bhanu, R., Mannucci, A. J., Lakhina, G. S., Kozyra, J. U., Shiokawa, K., Lee, L. C., Echer, E., Reddy, R. V., and Gonzalez, W. D.: Heliospheric plasma sheet (HPS) impingement onto the magnetosphere as a cause of relativistic electron dropouts (REDs) via coherent EMIC wave scattering with possible consequences for climate change mechanisms, J. Geophys. Res.-Space, 121, 10130–10156, https://doi.org/10.1002/2016JA022499, 2016.
Yamazaki, Y.: Large lunar tidal effects in the equatorial electrojet during northern winter and its relation to stratospheric sudden warming events, J. Geophys. Res.-Space, 118, 7268–7271, https://doi.org/10.1002/2013JA019215, 2013.
Yamazaki, Y.: Solar and lunar ionospheric electrodynamic effects during stratospheric sudden warmings, J. Atmos. Sol.-Terr. Phy., 119, 138–146, https://doi.org/10.1016/j.jastp.2014.08.001, 2014.
Yamazaki, Y. and Maute, A.: Sq and EEJ – A Review on the Daily Variation of the Geomagnetic Field Caused by Ionospheric Dynamo Currents, Space Sci. Rev., 206, 299–405, https://doi.org/10.1007/s11214-016-0282-z, 2017.
Yamazaki, Y. and Richmond, A. D.: A theory of ionospheric response to upward-propagating tides: Electrodynamic effects and tidal mixing effects, J. Geophys. Res.-Space, 118, 5891–5905, https://doi.org/10.1002/jgra.50487, 2013.
Yamazaki, Y., Yumoto, K., Uozumi, T., and Cardinal, M. G.: Intensity variations of the equivalent S current system along the 210° magnetic meridian, J. Geophys. Res.-Space, 116, A10308, https://doi.org/10.1029/2011JA016632, 2011.
Yamazaki, Y., Yumoto, K., McNamara, D., Hirooka, T., Uozumi, T., Kitamura, K., Abe, S., and Ikeda, A.: Ionospheric current system during sudden stratospheric warming events, J. Geophys. Res.-Space, 117, 1–7, https://doi.org/10.1029/2011JA017453, 2012a.
Yamazaki, Y., Richmond, A. D., Liu, H., Yumoto, K., and Tanaka, Y.: Sq current system during stratospheric sudden warming events in 2006 and 2009, J. Geophys. Res.-Space, 117, A12313, https://doi.org/10.1029/2012JA018116, 2012b.
Zou, Y., Donner, R. V., Marwan, N., Donges, J. F., and Kurths, J.: Complex network approaches to nonlinear time series analysis, Phys. Rep., 787, 1–97, https://doi.org/10.1016/j.physrep.2018.10.005, 2019.
Short summary
The contributing influence of SSWs (sudden stratospheric warming) on regional ionosphere through chaos theory is examined. We find that ionospheric chaos is more pronounced in the European sector compared to the African sector during an SSW. Evidence of orderliness behavior in regional ionosphere of African sector is observed. Finally, we notice that after the peak phase of an SSW, ionospheric chaos is found to be more pronounced.
The contributing influence of SSWs (sudden stratospheric warming) on regional ionosphere through...
