Abstract
The present study concentrates on the effects on the ionosphere of an individual severe magnetic Storm of the Sudden Commencement (SSC)type,with SSC taking place in the daytime hours.The storm started on 29 October 1968 and went on to 2 November 1968 with geomagnetic 3-hourly magnetic activity index reaching values of Kp ?7. Interplanetary magnetic field polarities included A (field polarity Away from the solar wind)positive and T (field polarity Towards the solar wind)negative polarities.In these conditions,the local response of true height of F-region (hF) ionization fails nonlinearly from fixed plasma densities.The interplanetary B z ,the magnetic field H - component and K p were examined for the 5 days following the sudden commencement.Due to intensive geomagnetic SC effects,the lower and upper limits of the F -regions were unbalanced because of gravity relaxation and solar wind pressure effects,until normal levels were restored.In the F -layer 70%deviations of critical frequencies (f 0 F )from median values,as well as hF level variations reaching hundreds of kilometers,were observed and were responsible for the destruction of communication channels.With a plasmapause location value L =1.6 and with K p ?7 the protonosphere reservoir should take 1.1 days for its replenishment;one day was in fact insufficient for a full plasma recovery.
Highlights
A Geomagnetic Storm (GS) is the result of strong enhancement of Ring Currents (RC) in which the Earth’s Magnetic Field (EMF) is usually depressed below its normal quiet day value
The present study aims to contribute to satellite communications and as well as to ionospheric model studies for especially high geomagnetic activity conditions
The results presented in the graphs may be summarized as follows: a) The F-layer starts to rise up in a rather normal way near sunset
Summary
Prölss (1987) investigated the temperature response of the upper thermosphere, and gave quantitative results on composition changes. He published a thermospheric model but suggested that further studies are required for negative ISs at middle latitudes. Hewish and Duffet-Smith (1987) suggested a means of giving warning of impending high speed solar wind streams at 1AU. This would allow predictions of time intervals where there will be higher probabilities of MS occurrence (Tsurtani et al, 1988). The present study aims to contribute to satellite communications and as well as to ionospheric model studies for especially high geomagnetic activity conditions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
