Study of post sunset vertical plasma drift at equatorial F-region using long-term (1990–2003) ionosonde measurements in Indian longitude

• Published in: Journal of atmospheric and solar-terrestrial physics Vol. 80; pp. 239 - 246
• Main Authors: Kakad, B., Tiwari, D., Pant, T.K.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-05-2012; Elsevier
• Subjects: Dipping; Drift; Earth, ocean, space; Equatorial ionosphere; Equinoxes; Exact sciences and technology; External geophysics; F-region vertical drift; Indian; Ionosonde; Ionosondes; Ionospheric soundings; Physics of the ionosphere; Seasons; Solar flux; Sunset; Asia; India; Equatorial ionosphere; F-region vertical drift; Ionosonde; Ionospheric sounder; Long term; lonosonde; Ionospheric F region; electrical field; Sunset; Ionospheric drift; Plasma drift; Vertical drift; Solar flux; Height
• ISSN: 1364-6826; 1879-1824
• DOI: 10.1016/j.jastp.2012.02.004

Ionosonde measurements from Trivandrum (77°E, 8.5°N, dip 0.5°N) are used to investigate the seasonal and solar flux dependence of peak height, and vertical drift of F layer in post sunset hours. The study reveals that pre- and post-reversal peak vertical drift of F layer increases with solar flux in all seasons. However, the rate of increase is found to be season dependent. Clear difference is observed in the solar flux dependence of peak height and vertical drift for two equinoxes. The post reversal peak westward electric field shows weak (strong) dependence on solar flux during November–February solstice (March–April, September–October equinox).
► Post-reversal peak vertical drift of F-layer is weakly depends on solar flux for NDJF. ► Solar flux dependence of Pre- and Post-reversal Vzp is different for two equinoxes. ► PRE is absent in May–August (June–July) during low to moderate (high) solar flux.