The Storm Time Evolution of the Ionospheric Disturbance Plasma Drifts

Abstract

In this paper, we use the C/NOFS and ROCSAT‐1 satellites observations to analyze the storm time evolution of the disturbance plasma drifts in a 24 h local time scale during three magnetic storms driven by long‐lasting southward IMF Bz. The disturbance plasma drifts during the three storms present some common features in the periods dominated by the disturbance dynamo. The newly formed disturbance plasma drifts are upward and westward at night, and downward and eastward during daytime. Further, the disturbance plasma drifts are gradually evolved to present significant local time shifts. The westward disturbance plasma drifts gradually migrate from nightside to dayside. Meanwhile, the dayside downward disturbance plasma drifts become enhanced and shift to later local time. The local time shifts in disturbance plasma drifts are suggested to be mainly attributed to the evolution of the disturbance winds. The strong disturbance winds arisen around midnight can constantly corotate to later local time. At dayside the westward and equatorward disturbance winds can drive the F region dynamo to produce the poleward and westward polarization electric fields (or the westward and downward disturbance drifts). The present results indicate that the disturbance winds corotated to later local time can affect the local time features of the disturbance dynamo electric field.

Equatorial Ionospheric Electrodynamics Over Jicamarca During the 6–11 September 2017 Space Weather Event

“…The ionospheric currents show the diverse patterns during the present three cases. Rastogi et al (), Xiong et al (), and Zhang, Liu, Le, Chen, and Kuai () showed that the flares induce the eastward EEJ to enhance, according with the result during X8.2 flare on 10 September. Rastogi et al (, ) and Sripathi et al () found that solar flares produce a westward increase under a counter EEJ, which is consistent with the result that the westward EEJ is increased on 6 September flare.…”

“…Geomagnetic storms are known to affect the ionospheric electrodynamics due to two types of sources, the penetration electric field from high to low latitudes (e.g., Kelley et al, 2003;Kikuchi et al, 1978) and disturbance dynamo electric field (DDEF) result from the storm-time changes in neutral winds (e.g., Blanc & Richmond, 1980;Zhang, Liu, Le, Chen, & Kuai, 2017). The penetration electric field happens mainly when the interplanetary magnetic field (IMF) Bz abruptly turns southward.…”

“…Fejer and Scherliess (1995) and Scherliess and Fejer (1997) used the altitudinal average observations from Jicamarca incoherent scatter radar (ISR) to understand the local time feature of the zonal electric field during geomagnetic activities and found that the DDEF is westward in dayside and eastward during nighttime. Using the Communication/Navigation Outage Forecasting System (C/NOFS) observations, Zhang, Liu, Le, Chen, and Kuai (2017) revealed that the local time variation of the DDEF changes with the temporal evolution of the storm time disturbance winds. The ROCSAT-1 data show that the evening downward and the nighttime upward disturbance plasma drifts are largest in the eastern and western hemispheres (e.g., Fejer et al, 2008;Xiong et al, 2016).…”

A Statistical Study on the Climatology of the Equatorial Plasma Depletions Occurrence at Topside Ionosphere During Geomagnetic Disturbed Periods

“…Xiong et al () found that the peak of the disturbance winds can corotate from 2300 to 0300 local time (LT) as they propagate from high to middle and low latitudes. Zhang et al () further provided observations that the DDEF could also be shifted to later local times. Hairston et al () showed a persistent enhanced downward plasma vertical drift at dayside and early evening hours through all phases of the 26 September 2011 storm, suggesting a total absence of the prompt penetration electric field.…”

Equatorial Ionospheric Disturbance Field‐Aligned Plasma Drifts Observed by C/NOFS

“…Geomagnetic storms are known to affect the field‐perpendicular plasma drifts due to the electric field penetrated from high to low latitudes (e.g., Kelley et al, ; Kikuchi et al, ) and disturbance dynamo electric field due to the storm time changes in neutral wind (e.g., Blanc & Richmond, ; Zhang et al, ). While penetration of electric field happens mainly during the main phase of geomagnetic storms, the disturbance dynamo electric field starts developing about 3–4 hr after the storm onset because of the time taken by the disturbance neutral wind to travel from high to low latitudes (e.g., Fujiwara et al, ; Huang et al, ; Xiong et al, ).…”