Study of VHF Ionospheric Scintillation During Geomagnetic Storms at Udaipur

Space weather refers to the conditions on the sun and the solar wind, magnetosphere, ionosphere and thermosphere that can influence the performance and reliability of space-borne and ground technological systems and can endanger human life or health. In this paper VHF amplitude scintillation recorded during the period 1991 to 2001 at low latitude Udaipur (24.60 N, 73.70 E, Dip angle 35 degree )are analysed to study the behaviour of ionospheric irregularities during active solar periods and magnetic storms. During a geomagnetic storm, the Sun and the magnetosphere are connected, giving rise severe changes both in interplanetary space and terrestrial environment. In the present study an attempt is made to further understand some of the observed storm time effects in terms of scintillation index and solar disturbance. It opened up new ways because observations in the interaction between the solar wind - magnetosphere - ionospheres during magnetic storms have progressed greatly. An attempt is made to identify and delineate the effects of a) storms on scintillation occurrences during Pre and post Mid-night Hours b) the development of generation and inhabitation of storm due to ring currents and c) the disturbance dynamo electric fields based on Aaron’s hypothesis.