• P-ISSN 0974-6846 E-ISSN 0974-5645

Indian Journal of Science and Technology


Indian Journal of Science and Technology

Year: 2020, Volume: 13, Issue: 35, Pages: 3642-3651

Original Article

On the vector plasma drift measurements over Equatorial Ionosphere using HF Doppler radar – A brief review

Received Date:21 July 2020, Accepted Date:14 September 2020, Published Date:03 October 2020


Background/ Objective: University of Kerala, Thiruvananthapuram ( 8.5◦N ,77◦E, dip 0.5◦N ) in India had a lively Space Physics research group since 1982, owing to proximity of the location to the geomagnetic dip equator. In 1982, a single frequency HF Doppler radar, operational at 5.5 MHz was installed in the University which provided many invaluable scientific results regarding the night time ionospheric F region. In 2003, it was upgraded to a new multifrequency HF Doppler Radar thereby enabling detailed examination of vertical plasma drift measurements at three different altitudes of F-region, in a nearsimultaneous manner. Methods: This study is basically a brief review of major results of F –region electrodynamics over Indian longitudinal sector obtained exclusively using HF Radar data. Findings: This review brings all the scientific results obtained using HF Radar about vertical drift studies over equatorial latitude and found that nearly about 40 research papers have been published in reputed national and international journals using the Radar data. Novelty: In a complementary point of view, this gives an opportunity to revisit and remember the important contributions of many of the earlier Indian scientists, who enriched ionospheric science using this unique facility.

Keywords: HF Doppler Radar; Ionosphere; Vertical drift


  1. Fejer BG, Gonzales CA, Farley DT, Kelley MC, Woodman RF. Equatorial electric fields during magnetically disturbed conditions 1. The effect of the interplanetary magnetic field. Journal of Geophysical Research. 1979;84(A10). Available from: https://dx.doi.org/10.1029/ja084ia10p05797
  2. Fejer BG, Kudeki E, Farley DT. Equatorial F region zonal plasma drifts. Journal of Geophysical Research. 1985;90(A12). Available from: https://dx.doi.org/10.1029/ja090ia12p12249
  3. Ramesh KB, Sastri JH. Solar cycle and seasonal variations in F-region vertical drifts over Kodaikanal, India. Annales Geophysicae. 1995;13(6):633–640. Available from: https://dx.doi.org/10.1007/s00585-995-0633-7
  4. Subbarao KSV, Murthy BVK. Post-sunset F-region vertical velocity variations at magnetic equator. J Atmos Terr Phys. 1994;56(1):59–65. Available from: https://doi.org/10.1016/0021-9169(94)90176-7
  5. Balan N, Murthy K, Reddi CR, Rao PB, Subbarao KSV, . Proc Indian Natl Sci Acad. (Vol. 48) 1982.
  6. Jayachandran B, Balan N, Nampoothiri SP, Rao PB. HF Doppler observations of vertical plasma drifts in the evening F region at the equator. Journal of Geophysical Research. 1987;92(A10). Available from: https://dx.doi.org/10.1029/ja092ia10p11253
  7. Namboothiri SP, Jayachandran B, Balan N, Rao PB. Vertical plasma drifts in the post-sunset F-region at the magnetic equator. Journal of Atmospheric and Terrestrial Physics. 1988;50(12):1087–1091. Available from: https://dx.doi.org/10.1016/0021-9169(88)90097-9
  8. Namboothiri SP, Balan N, Rao PB. Vertical plasma drifts in the F region at the magnetic equator. Journal of Geophysical Research. 1989;94(A9). Available from: https://dx.doi.org/10.1029/ja094ia09p12055
  9. Somayjulu VV, Murthy K. Nature of association of equatorial spread F with magnetic activity. Nature. 1976;263:36–37. Available from: https://www.nature.com/articles/263036a0
  10. Fejer BG, Farley DT, Woodman RF, C. Dependence of equatorial F region vertical drifts on season and solar cycle. J Geophys Res. ;p. 5792–5796. Available from: https://doi.org/10.1029/JA084iA10p05792
  11. Woodman RF, Rastogi RG, Calderon C. Solar cycle effects on the electric fields in the equatorial ionosphere. J Geophys Res. 1997;82:5257–5261. Available from: https://doi.org/10.1029/JA075i031p06249
  12. Nair RB, Balan N, Bailey GJ, Rao PB. Spectra of the ac electric fields in the post-sunset F-region at the magnetic equator. Planetary and Space Science. 1992;40(5):655–662. Available from: https://dx.doi.org/10.1016/0032-0633(92)90006-a
  13. Fejer BG, Larsen MF, Farley DT. Equatorial disturbance dynamo electric fields. Geophysical Research Letters. 1983;10(7):537–540. Available from: https://dx.doi.org/10.1029/gl010i007p00537
  14. Balan N, Jayachandran B, Nair RB, Namboothiri SP, Bailey GJ, Rao PB. HF Doppler observations of vector plasma drifts in the evening F-region at the magnetic equator. Journal of Atmospheric and Terrestrial Physics. 1992;54(11-12):1545–1554. Available from: https://dx.doi.org/10.1016/0021-9169(92)90162-e
  15. Sastri JH, Varma VKM, Nayar SRP. Height gradient of F region vertical drift in the evening equatorial ionosphere. Geophysical Research Letters. 1995;22(19):2645–2648. Available from: https://dx.doi.org/10.1029/95gl02668
  16. Joymon D, Solomon S, Nayar SR. HF Doppler radar observations on the relationship between electrostatic turbulence and equatorial spread-F. Ind J Radio And Space Phys . 1996a;25:340–344. Available from: http://nopr.niscair.res.in/handle/123456789/35680
  17. Joymon D, Solomon S, George TM, Meena VK, R NS. Observation of day-to-day and seasonal variability in vertical F-region plasma drift at magnetic equator using HF Doppler radar. Ind J Radio And Space Phys. 1996;25:158–162. Available from: https://www.researchgate.net/publication/286896902
  18. Joymon D, Solomon S, George TM, Nayar SR. Magnetic activity dependence of vertical plasma drift and its influence on spread-F. Ind J Radio And Space Phys. 1997;26:213–217. Available from: http://nopr.niscair.res.in/bitstream/123456789/35522/1
  19. George T, Joymon D, Solomon S, Rajesh P, Nayar S, Revathy K. Fluctuations in vertical plasma drift and magnetic activity. J Atmos Terr Phys. 1998;27:233–235. Available from: http://nopr.niscair.res.in/handle/123456789/35314
  20. Nayar SR, Sreehari CV, Shibu S, Devassia C, Rao KSV, SVM. Multi-frequency HF Doppler radar observations of vertical plasma drift - Preliminary results . Ind J Radio And Space Phys. 2005;34:233–242. Available from: http://hdl.handle.net/123456789/19319
  21. Murphy JA, Heelis RA. Implications of the relationship between electromagnetic drift components at mid and low latitudes. Planetary and Space Science. 1986;34(7):645–652. Available from: https://dx.doi.org/10.1016/0032-0633(86)90042-5
  22. Nayar SR, Bhuvanendran C, Jyoti N, Devasia CV, Subbarao KSV. Meridional wind derived from HF doppler radar and ionosonde over the magnetic equator. Ind J Radio And Space Phys. 2004;33:367–372. Available from: http://hdl.handle.net/123456789/19341
  23. Igi S, Ogawa T, Oliver WL, Fukao S. Thermospheric winds over Japan: Comparison of ionosonde and radar measurements. American Geophysical Union (AGU). 1995. doi: 10.1029/95ja02387 Available from: https://dx.doi.org/10.1029/95ja02387
  24. Nayar SRP, Mathew TJ, Sreehari CV, Sumod SG, Devasia CV, Ravindran S, et al. Electrodynamics of the equatorial F-region ionosphere during pre-sunrise period. Annales Geophysicae. 2009;27(1):107–111. Available from: https://dx.doi.org/10.5194/angeo-27-107-2009
  25. Mathew TJ, Nayar SRP, Ravindran S, Pant T. Characteristics of the equatorial F-region vertical plasma drift observed during post-sunset and pre-sunrise hours. Advances in Space Research. 2010;46(5):618–625. Available from: https://dx.doi.org/10.1016/j.asr.2010.04.023


© 2020 Simi et al.This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Published By Indian Society for Education and Environment (iSee).


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