The geomagnetic storm effect on ionospheric vertical E×B drift is analysed using Communication/Navigation Outage and Forecasting System(C/NOFS)Satellite data,magnetometer data,and solar wind data,over the East Af...The geomagnetic storm effect on ionospheric vertical E×B drift is analysed using Communication/Navigation Outage and Forecasting System(C/NOFS)Satellite data,magnetometer data,and solar wind data,over the East Afri-can low latitude region during the period 2008-2015.We identified a total of 608 corotating interaction region(CIR)-driven and 23 coronal mass ejec-tion(CME)-driven geomagnetic storms in this study.Most of the CIR-driven storms were observed during the declining phase of solar cycle 24 in 2015.The CME-driven storms,on the other hand,were dominant during the near max-imum phase of the solar cycle 24 in 2012.The C/NOFS satellite data was found to be consistent with magnetometer observations in identifying both upward and downward vertical E×B drift occurrence.The common result of analysed CME-driven geomagnetic storms was enhancement in E×B drifts due to pres-ence of eastward prompt penetrating electric fields(PPEFs)during the storm main phase.There was also a decrease in E×B due to the decrease in hori-zontal component of the magnetic field(ΔH)during the recovery phases of the CME-driven storms.This is a manifestation of downward E×B drifts as-sociated with westward electric field,which is due to the disturbance dynamo contribution.During CIR-driven geomagnetic storms,the storm’s main phases were also dominated by downward E×B drifts associated with westward elec-tric field,which is due to disturbance dynamo.展开更多
文摘The geomagnetic storm effect on ionospheric vertical E×B drift is analysed using Communication/Navigation Outage and Forecasting System(C/NOFS)Satellite data,magnetometer data,and solar wind data,over the East Afri-can low latitude region during the period 2008-2015.We identified a total of 608 corotating interaction region(CIR)-driven and 23 coronal mass ejec-tion(CME)-driven geomagnetic storms in this study.Most of the CIR-driven storms were observed during the declining phase of solar cycle 24 in 2015.The CME-driven storms,on the other hand,were dominant during the near max-imum phase of the solar cycle 24 in 2012.The C/NOFS satellite data was found to be consistent with magnetometer observations in identifying both upward and downward vertical E×B drift occurrence.The common result of analysed CME-driven geomagnetic storms was enhancement in E×B drifts due to pres-ence of eastward prompt penetrating electric fields(PPEFs)during the storm main phase.There was also a decrease in E×B due to the decrease in hori-zontal component of the magnetic field(ΔH)during the recovery phases of the CME-driven storms.This is a manifestation of downward E×B drifts as-sociated with westward electric field,which is due to the disturbance dynamo contribution.During CIR-driven geomagnetic storms,the storm’s main phases were also dominated by downward E×B drifts associated with westward elec-tric field,which is due to disturbance dynamo.
