Acta Geophysica

, Volume 62, Issue 3, pp 656–678 | Cite as

Quantifying the EEJ current with ground-based ionosonde inferred vertical E × B drifts in the morning hours over Ilorin, West Africa

  • Jacob O. Adeniyi
  • Isaac A. Adimula
  • Babatunde O. Adebesin
  • Bodo W. Reinisch
  • Olusola A. Oladipo
  • Olayinka Olawepo
  • Kiyohumi Yumoto
Research Article


The relationship between the ground-based inferred vertical E × B drifts, Vz, and the magnetic equatorial electrojet current during the year of solar minima was presented. Both the diurnal and seasonal Vz variations are positively directed during the daytime and negative at nighttime. The evening time pre-reversal enhancement occurs around 19:00 LT. The fairly strong linear relationship between the electrojet current strength and Vz exhibited higher correlations during the daytime (06:00–16:00 LT). The maximum morning time proxy parameter described by E = [dH ILR)/dt]max in the morning hours, indicating the east-west electric field in the EEJ, corresponds reasonably well with the E × B drift and, hence, can be used as a proxy parameter for representing Vz in the morning hours. The daytime EEJ magnitude seasonal changes are connected with a change in conductivity emerging from the action of turbulence and divergence of momentum flux. These waves above the dynamo region are suggested to lead to partial counter electrojet during the equinoctial months.


equatorial electrojet E × B drifts counter electrojet electric field pre-reversal enhancement 


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  1. Abdu, M.A., G.O. Walker, B.M. Reddy, E.R. de Paula, J.H.A. Sobral, and B.G. Fejer (1993), Global scale equatorial ionization anomaly (EIA) response to magnetospheric disturbances based on the May-June 1987 SUNDIALcoordinated observations, Ann. Geophys. 11,7, 585–594.Google Scholar
  2. Abdu, M.A., T.K. Ramkumar, I.S. Batista, C.G.M. Brum, H. Takahasi, B.W. Reinisch, and J.H.A. Sobral (2006), Planetary wave signatures in the equatorial atmosphere-ionosphere system, and mesosphere — E- and F-region coupling, J. Atmos. Sol.-Terr. Phys. 68,3–5, 509–522, DOI: 10.1016/j.jastp.2005.03.019.CrossRefGoogle Scholar
  3. Adebesin, B.O. (2008), Roles of interplanetary and geomagnetic parameters in “intense” and “very intense” magnetic storms generation and their geoeffectiveness, Acta Geod. Geophys. Hu. 43,4, 383–408, DOI: 10.1556/AGeod.43.2008.4.2.CrossRefGoogle Scholar
  4. Adebesin, B.O., S.O. Ikubanni, S.J. Adebiyi, and B.W. Joshua (2013a), Multi-station observation of ionospheric disturbance of March 9, 2012 and comparison with IRI-model, Adv. Space. Res. 52,4, 604–613, DOI: 10.1016/j.asr2013.05.002.CrossRefGoogle Scholar
  5. Adebesin, B.O., J.O. Adeniyi, I.A. Adimula, and B.W. Reinisch (2013b), Equatorial vertical plasma drift velocities and electron densities inferred from groundbased ionosonde measurements during low solar activity, J. Atmos. Sol.-Terr. Phys. 97, 58–64, DOI: 10.1016/j.jastp.2013.02.010.CrossRefGoogle Scholar
  6. Adebesin, B.O., J.O. Adeniyi, I.A. Adimula, and B.W. Reinisch (2013c), Low latitude nighttime ionospheric vertical E × B drifts at African region, Adv. Space Res. 52,12, 2226–2237, DOI: 10.1016/j.asr.2013.09.033.CrossRefGoogle Scholar
  7. Adebesin, B.O., J.O. Adeniyi, I.A. Adimula, B.W. Reinisch, and K. Yumoto (2013d), F2 layer characteristics and electrojet strength over an equatorial station, Adv. Space Res. 52,5, 791–800, DOI: 10.1016/j.asr.2013.05.025.CrossRefGoogle Scholar
  8. Adeniyi, J.O. (1986), Magnetic storm effects on the morphology of the equatorial F2-layer, J. Atmos. Sol.-Terr. Phys. 48,8, 695–702, DOI: 10.1016/0021-9169(86)90019-X.CrossRefGoogle Scholar
  9. Adimula, I.A., A.B. Rabiu, Y. Yumoto, and the MAGDAS Group (2011), Geomagnetic field variations from some equatorial electrojet stations, Sun Geosphere 6,2, 45–49.Google Scholar
  10. Anderson, D., A. Anghel, K. Yumoto, M. Ishitsuka, and E. Kudeki (2002), Estimating daytime vertical E × B drift velocities in the equatorial F-region using ground-based magnetometer observations, Geophys. Res. Lett. 29,12, 37-1–37-4, DOI: 10.1029/2001GL014562.CrossRefGoogle Scholar
  11. Anderson, D., A. Anghel, J.L. Chau, and O. Veliz (2004), Daytime vertical E × B drift velocities inferred from ground-based magnetometer observations at low latitudes, Space Weather 2,11, S11001, DOI: 10.1029/2004SW000095.CrossRefGoogle Scholar
  12. Anderson, D., E. Araujo-Pradere, and L. Scherliess (2009), Comparing daytime, equatorial E × B drift velocities and TOPEX/TEC observations associated with the 4-cell, non-migrating tidal structure, Ann. Geophys. 27, 2861–2867, DOI: 10.5194/angeo-27-2861-2009.CrossRefGoogle Scholar
  13. Araujo-Pradere, E.A., D.N. Anderson, M. Fedrizzi, and R. Stoneback (2010), Quantifying the daytime, equatorial E × B drift velocities at the boundaries of the 4-cell tidal structure using C/NOFS’ CINDI observations. In: P. Doherty, M. Hernández-Pajares, J.M. Juan, J. Sanz, and A. Aragon-Angel (eds.), Proc. Int. Beacon Satellite Symposium 2010, 7–11 June 2010, Barcelona, Spain.Google Scholar
  14. Bolaji, O.S., A.B. Rabiu, I.A. Adimula, J.O. Adeniyi, and K. Yumoto (2011), Interhemispheric trans-equatorial field-aligned currents deduced from MAGDAS at equatorial zone, Space Res. J. 4,1, 12–22, DOI: 10.3923/srj.2011.12.22.CrossRefGoogle Scholar
  15. Devasia, C.V., V. Sreeja, and S. Ravindran (2006), Solar cycle dependent characteristics of the equatorial blanketing Es layers and associated irregularities, Ann. Geophys. 24,11, 2931–2947.CrossRefGoogle Scholar
  16. Fang, T.W., A.D. Richmond, J.Y. Liu, A. Maute, C.H. Lin, C.H. Chen, and B. Harper (2008), Model simulation of the equatorial electrojet in the Peruvian and Philippine sectors, J. Atmos. Sol.-Terr. Phys. 70,17, 2203–2211, DOI: 10.1016/j.jastp.2008.04.021.CrossRefGoogle Scholar
  17. Fejer, B.G., and L. Scherliess (1997), Empirical models of storm time equatorial zonal electric fields, J. Geophys. Res. 102,A11, 24047–24056, DOI: 10.1029/97JA02164.CrossRefGoogle Scholar
  18. Fejer, B.G., E.R. de Paula, S.A. González, and R.F. Woodman (1991), Average vertical and zonal F region plasma drifts over Jicamarca, J. Geophys. Res. 96,A8, 13901–13906, DOI: 10.1029/91JA01171.CrossRefGoogle Scholar
  19. Fritts, D.C., and M.J. Alexander (2003), Gravity wave dynamics and effects in the middle atmosphere, Rev. Geophys. 41,1, 1003, DOI: 10.1029/2001RG000106.CrossRefGoogle Scholar
  20. Huang, X., and B.W. Reinisch (1996), Vertical electron density profiles from Digisonde ionograms. The average representative profile, Ann. Geophys. 39,4, 751–756, DOI: 10.4401/ag-4010.Google Scholar
  21. Liu, L., W. Wan, Y. Chen, and H. Le (2011), Solar activity effects of the ionosphere: A brief review, Chinese Sci. Bull. 56,12, 1202–1211, DOI: 10.1007/s11434-010-4226-9.CrossRefGoogle Scholar
  22. Oyekola, O.S., and L.B. Kolawole (2010), Equatorial vertical E × B drift velocities inferred from ionosonde measurements over Ouagadougou and the IRI-2007 vertical ion drift model, Adv. Space Res. 46,5, 604–612, DOI: 10.1016/j.asr.2010.04.003.CrossRefGoogle Scholar
  23. Rabiu, A.B., A.I. Mamukuyomi, and E.O. Joshua (2007), Variability of equatorial ionosphere inferred from geomagnetic field measurements, Bull. Astron. Soc. India 35,4, 607–618.Google Scholar
  24. Radicella, S.M., and J.O. Adeniyi (1999), Equatorial ionospheric electron density below the F2 peak, Radio Sci. 34,5, 1153–1163, DOI: 10.1029/1999RS900071.CrossRefGoogle Scholar
  25. Scherliess, L., and B.G. Fejer (1999), Radar and satellite global equatorial F region vertical drift model, J. Geophys. Res. 104,A4, 6829–6842, DOI: 10.1029/1999JA900025.CrossRefGoogle Scholar
  26. Sreeja, V., C.V. Devasia, S. Ravindran, and T.K. Pant (2009), Observational evidence for the plausible linkage of Equatorial Electrojet (EEJ) electric field variations with the post sunset F-region electrodynamics, Ann. Geophys. 27, 4229–4238, DOI: 10.5194/angeo-27-4229-2009.CrossRefGoogle Scholar
  27. Uemoto, J., T. Maruyama, S. Saito, M. Ishii, and R. Yoshimura (2010), Relationships between pre-sunset electrojet strength, pre-reversal enhancement and equatorial spread-F onset, Ann. Geophys. 28,2, 449–454, DOI: 10.5194/angeo-28-449-2010.CrossRefGoogle Scholar
  28. Vineeth, C., T.K. Pant, and M.M. Hossain (2012a), Enhanced gravity wave activity over the equatorial MLT region during counter electrojet events, Indian J. Radio Space Phys. 41,2, 258–263.Google Scholar
  29. Vineeth, C., T.K. Pant, K.K. Kumar, L. Jose, S.G. Sumod, and S. Alex (2012b), Counter equatorial electrojet: Analysis of the variability in daytime mesopause temperature and winds, J. Atmos. Sol.-Terr. Phys. 75–76, 115–121, DOI: 10.1016/j.jastp.2011.07.005.CrossRefGoogle Scholar
  30. Woodman, R.F., J.L. Chau, and R.R. Ilma (2006), Comparison of ionosonde and incoherent scatter drift measurements at the magnetic equator, Geophys. Res. Lett. 33,1, L01103, DOI: 10.1029/2005GL023692.CrossRefGoogle Scholar
  31. Yumoto, K., and the MAGDAS Group (2007), Space weather activities at SERC for IHY: MAGDAS, Bull. Astron. Soc. India 35,4, 511–522.Google Scholar

Copyright information

© Versita Warsaw and Springer-Verlag Wien 2014

Authors and Affiliations

  • Jacob O. Adeniyi
    • 1
  • Isaac A. Adimula
    • 1
  • Babatunde O. Adebesin
    • 2
  • Bodo W. Reinisch
    • 3
  • Olusola A. Oladipo
    • 1
  • Olayinka Olawepo
    • 1
  • Kiyohumi Yumoto
    • 4
  1. 1.Department of PhysicsUniversity of IlorinIlorinNigeria
  2. 2.Department of Industrial PhysicsLandmark UniversityOmu-Aran, Kwara StateNigeria
  3. 3.Lowell Digisonde International, LLCLowellUSA
  4. 4.Space Environment Research CenterKyushu UniversityFukuokaJapan

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