Solar-wind and IMF-Bz inclined Precusor of Geomagnetic Induced Currents and their Significance

The geoeffective extent of some solar wind and interplanetary parameters causing extreme
$dB/dt$
(time rate of change of magnetic field) perturbation, a proxy parameter for measuring the geoelectric field and hence the Geomagnetic induced current (GIC) during storm activity (of 20 November 2003) at different latitudes along chain of stations around 300°E longitude was investigated. Both observational and simulation responses of these parameters were presented. The observational result shows that the largest
$dB/dt$
values occur in the high latitudes and decreases with decreasing latitude except at equatorial location whose magnitude upshots (the low- and mid-latitudes). The amplification factor (
$A_{f}$
) defined by
$[dB/dt]/[d(SYM- H)/dt]$
at equatorial latitude is comparable to that at high latitude. The simulated result revealed that fluctuating flow speed (
$V$
) could trigger earlier response from the magnetosphere while the response due to fluctuating proton density (
$Np$
) could have a lasting effect on the magnetosphere. The simulated
$dB/dt$
perturbation magnitude for fluctuating
$V$
was higher than that of the corresponding
$Np$
and IMF-Bz. For all simulated fluctuating conditions, significant perturbation was observed in all latitudes except the high-latitude, where it was suggested that all three parameters must be simultaneously active for the emergence of appreciable
$dB/dt$
observation. Our result revealed that different modulators are responsible for extreme
$dB/dt$
perturbation at high- and equatorial latitudes. On the geoeffectiveness, we suggested that all three parameters are necessary for a proper identification of magnetic field response to geomagnetically disturbed phenomenon.