F2-layer response to a Storm time disturbance at equatorial/low and mid-latitudes

Adebesin, B.O. and Adekoya, B. J. (2013) F2-layer response to a Storm time disturbance at equatorial/low and mid-latitudes. Sun and Geosphere., 8 (1). pp. 33-39. ISSN 1819-0839.

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The F2-layer response to a magnetic disturbance (Dst = -216nT) during the onset, main and recovery phases were investigated, using the percentage normalized deviation of the critical frequency (%D(foF2)). Observations were from the equatorial/low and mid-latitude stations. The onset phase recorded the highest enhancement at an equatorial station, Darwin (52%), and the least at a station along the equatorial ionization anomaly, Learmonth (23%). No significant response was observed for Puerto-Rico and Dyess. The main phase responded to a positive enhancement only at Learmonth, with a magnitude of 105%. Other stations (except Eglin AFB) recorded depletions ranging from 25-45%. We suggested non-simultaneous appearance of significant (D(foF2) ≥ 20%) response in the positive and negative phases of storms at 3h. segmented intervals of the first 12h. duration stretch during the recovery phase. This assertion is still left open. The simultaneous enhancement over Darwin and Learmonth during the first 9h. (1200-2100 24 August) of the recovery phase is attributed to the action of the eastward electric field; whereas the depletion observed in the midlatitude stations and Puerto-Rico during the recovery phase finds its explanation in the rapid heating of the polar atmosphere during energy income from the magnetosphere. We conclude that the disturbance prompt penetration electric fields (PPEF), and the large IMF Bz southward orientation are the major disturbed time modifying factor of the equatorial and low latitude ionosphere in this study.

Item Type: Article
Subjects: Q Science > QB Astronomy
Q Science > QC Physics
Divisions: Faculty of Engineering, Science and Mathematics > School of Physics
Depositing User: DR. B. OLUFEMI ADEBESIN
Date Deposited: 12 Jun 2015 20:27
Last Modified: 12 Jun 2015 20:27
URI: https://eprints.lmu.edu.ng/id/eprint/231

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