New aspects of the ionospheric response to the October 2003 superstorms from multiple‐satellite observations

Abstract

The total electron content (TEC) data measured by the Jason, CHAMP, GRACE, and SAC-C satellites, the in situ electron densities from CHAMP and GRACE, and the vertical E × B drifts from the ROCSAT, have been utilized to examine the ionospheric response to the October 2003 superstorms. The combination of observations from multiple satellites provides a unique global view of ionospheric storm effects, especially over the Pacific Ocean and American regions, which were under sunlit conditions during the main phases of the October 2003 superstorms. The main results of this study are as follows: (1) There were substantial increases in TEC in the daytime at low and middle latitudes during both superstorms. (2) The enhancements were greater during the 30 October superstorm and occurred over a wider range of local times. (3) They also tended to peak at earlier local times during this second event. (4) These TEC enhancement events occurred at the local times when there were enhancements in the upward vertical drift. (5) The strong upward vertical drifts are attributed to penetration electric fields, suggesting that these penetration electric fields played a significant role in the electron density enhancements during these superstorms. Overall, the main contribution of this study is the simultaneous view of the storm time ionospheric response from multiple satellites, and the association of local time differences in ionospheric plasma response with measured vertical drift variations.

Interhemispheric Asymmetry in Response of Low‐Latitude Ionosphere to Perturbation Electric Fields in the Main Phase of Geomagnetic Storms

“…While peaks over BOGT are observed at 20 and 21 UT, over UNSA they are seen about 18.5 UT and at about 21.5 UT and over CORD at about 21 and 22 UT. This result corroborates the evidence provided by Lei et al (2014) for this particular storm that "variations of vertical drifts played a significant role in creating the main features of the positive ionospheric storm" on 29 October 2003. Tracing the cause for the sudden enhancements in VTEC after 18 UT in interplanetary and equatorial parameters points toward the southward turning of IMF Bz at 18 UT concurrent with rise in E × B drift over the dip equator.…”

Regional differences of the ionospheric response to the July 2012 geomagnetic storm

“…The GRACE mission comprises two identical spacecraft, then the TEC between the two satellites can be calculated from the phase difference by the dual K‐band observations. The in situ electron densities obtained by dividing the intersatellite distances from the TEC between the two satellites are used to supplement the GRACE up‐looking TEC data [ Lei et al , ].…”

Effects of ionizing energetic electrons and plasma transport in the ionosphere during the initial phase of the December 2006 magnetic storm

“…At equatorial and low latitudes, a trough was formed between the slightly enhanced crests of the equatorial ionization anomaly (EIA) at 1600–1800 UT. That feature was an evidence of enhanced fountain effect [ Lei et al , , ; Kikuchi et al , ; Wei et al , ]. Namely, the oscillatory IMF B z caused multiple interplanetary electric field penetration into the equatorial ionosphere, and hence dayside ionospheric plasma uplift, which drives the equatorial fountain effect.…”