Spike‐like change of the vertical E × B drift in the equatorial region during very large geomagnetic storms

Abstract

We investigate the characteristics of the storm‐time disturbance electric fields in the equatorial region using the measurements of the vertical ion velocity from the Defense Meteorological Satellite Program F13 and the first Republic of China Satellite during the selected 43 geomagnetic storms of Dst <−100 nT in 2000–2004. The distinguishing feature in both observations is the occurrence of the spike‐like vertical E × B drift during the main phase of very large storms (Dst <−150 nT). The spikes occur simultaneously at different local times but the direction of the spikes shows a dependence on the local time. The spikes are upward on the dayside and downward on the nightside. The observed characteristics of the spikes can be explained by the penetration of the dawn‐to‐dusk polar cap electric field to low latitude.

The role of the vertical &lt;I&gt;&lt;B&gt;E&lt;/B&gt;&lt;/I&gt;×&lt;I&gt;&lt;B&gt;B&lt;/B&gt;&lt;/I&gt; drift for the formation of the longitudinal plasma density structure in the low-latitude F region

“…Oh (oh@spweather.com) 2007; Scherliess et al, 2008). The observations of similar periodic structures in the daytime equatorial electrojet (England et al, 2006a;Mouël et al, 2006) and equatorial vertical ion velocity on the topside (Hartman and Heelis, 2007;Kil et al, 2007) supported the association of the longitudinal density structure with the daytime vertical drift of equatorial plasma. The diurnal non-migrating eastward-propagating tide with zonal wave number-3 (DE3 tide) was suggested as the driver of the longitudinal variation of the vertical E×B drift (England et al, 2006a, b;Immel et al, 2006) and Hagan et al (2007) and showed the capability to produce the observed wave-4 density structure by the effect of the DE3 tide.…”

“…Second, the grouping of the longitude sectors following the magnetic field configuration was not an effective method. The longitudinal E×B drift structure inferred from the observations of equatorial electrojet (England et al, 2006a) and in situ ion velocity measurements (Kil et al, 2007) did not show any notable dependence on the geomagnetic field configuration. Third, the combination of the AE-E data with Jicamarca radar data in the Peruvian sector might rather increase errors in that sector since the E×B drift is largely variable in the Peruvian sector.…”

“…The formation of a longitudinally periodic plasma density structure in the low-latitude F region is now well known from extensive studies in recent years (Sagawa et al, 2005;Immel et al, 2006;Kil et al, 2007;Lin et al, 2007;Lühr et al, Correspondence to: S.-J. Oh (oh@spweather.com) 2007; Scherliess et al, 2008).…”

Occurrence of Equatorial Plasma Bubbles during Intense Magnetic Storms

“…• W geographic longitude, as well as with other space-based and groundbased measurements [1][2][3][4][5][6][7][8][9][10][11][12][13][14], and numerically simulated with global ionospheric models [15][16][17][18]. Huang et al [6,7,14] and Huang [11] found that penetration electric fields in the ionosphere can last for several hours without obvious attenuation during continuous southward IMF.…”

Positive ionospheric storm effects at Latin America longitude during the superstorm of 20–22 November 2003: revisit

“…Meanwhile, the dayside source of the polar tongue of ionization (TOI) has been proved to be the plume of SED transported from low latitudes in the post-noon sector by the subauroral disturbance electric field using the global GPS network and SuperDARN and DMSP observations . At low latitudes, spike-like changes of the equatorial F-region upward E × B drift were observed with the DMSP and ROCSAT-1 satellite measurements at 14:00, 18:00 and 09:30 LT during the main phase of the magnetic storm (Kil et al, 2007;Heelis and Coley, 2007). This is a consequence of the leakage of the dawn-to-dusk polar cap electric field to lower latitudes known as the prompt penetration electric fields (PPEF) when the interplanetary magnetic field (IMF) has a large southward component (e.g., Fejer et al, 1979;Kelley et al, 1979Kelley et al, , 2003.…”