Modeling storm-time electrodynamics of the low-latitude ionosphere–thermosphere system: Can long lasting disturbance electric fields be accounted for?

2007 ◽  
Vol 69 (10-11) ◽  
pp. 1182-1199 ◽  
Author(s):  
Naomi Maruyama ◽  
Stanislav Sazykin ◽  
Robert W. Spiro ◽  
David Anderson ◽  
Adela Anghel ◽  
...  
Keyword(s):  
Electric Fields ◽  
Low Latitude ◽  
Low Latitude Ionosphere

scholarly journals Effects of strong IMF <I>B<sub>z</sub></I> southward events on the equatorial and mid-latitude ionosphere

2009 ◽  
Vol 27 (3) ◽  
pp. 1175-1187 ◽  
Author(s):  
E. Astafyeva
Keyword(s):  
Electric Fields ◽  
Geomagnetic Storms ◽  
The Other ◽  
Negative Events ◽  
Equatorial Anomaly ◽  
Low Latitude ◽  
Sudden Drop ◽  
Ionospheric Response ◽  
Peak Structure ◽  
Low Latitude Ionosphere

Abstract. Dayside ionospheric response to five intense geomagnetic storms (Dst<−120 nT) that occurred in 2001–2005 was investigated by use of simultaneous TEC measurements by the CHAMP, SAC-C, TOPEX/Jason-1 satellites. Since the satellites passed over different longitudinal sectors and measured TEC in different range of altitudes, it was possible to obtain information about altitudinal and longitudinal ionosphere redistribution during these storms. Severe enhancements (up to ~350%) of the equatorial and mid-latitude TEC above ~430 km with concurrent traveling of the equatorial anomaly crests for a distance of 10–15° of latitude were observed during two of the five events analyzed here (6 November 2001 and 8 November 2004). This phenomenon, known as the dayside ionosphere uplift, or the "daytime super-fountain effect", occurred after sudden drop in IMF Bz and consequent penetration of the electric fields to the low-latitude ionosphere. However, the same order Bz negative events caused comparatively weak changes in the dayside TEC (up to ~80 TECU) during the other three events of 18 June 2003, 11 February 2004 and 24 August 2005. At the main phase of these storms there were mostly observed formation of the "typical" dual peak structure of the equatorial anomaly rather than the reinforcement of the fountain effect and the anomaly itself. Possible reasons and factors responsible for the development of the extreme ionosphere effects are discussed in the paper.

scholarly journals Oxygen ion uplift and satellite drag effects during the 30 October 2003 daytime superfountain event

2007 ◽  
Vol 25 (3) ◽  
pp. 569-574 ◽  
Author(s):  
B. T. Tsurutani ◽  
O. P. Verkhoglyadova ◽  
A. J. Mannucci ◽  
T. Araki ◽  
A. Sato ◽  
...  
Keyword(s):  
Electric Fields ◽  
Upward Motion ◽  
Quiet Time ◽  
Low Latitude ◽  
Satellite Drag ◽  
Oxygen Ion ◽  
Low Altitude ◽  
Low Latitude Ionosphere

Abstract. The prompt penetration of interplanetary electric fields (IEFs) to the dayside low-latitude ionosphere during the first ~2 h of a superstorm is estimated and applied to a modified NRL SAMI2 code for the 30 October 2003 event. In our simulations, the dayside ionospheric O+ is convected to higher altitudes (~600 km) and higher latitudes (~±25° to 30°), forming highly displaced equatorial ionospheric anomaly (EIA) peaks. This feature plus others are consistent with previously published CHAMP electron (TEC) measurements and with the dayside superfountain model. The rapid upward motion of the O+ ions causes neutral oxygen (O) uplift due to ion-neutral drag. It is estimated that above ~400 km altitude the O densities within the displaced EIAs can be increased substantially over quiet time values. The latter feature will cause increased drag for low-altitude satellites. This newly predicted phenomenon is expected to be typical for superstorm/IEF events.

Penetration of Magnetospheric Electric Fields to the Low Latitude Ionosphere During Storm/Substorms

2011 ◽  
pp. 443-453 ◽  
Author(s):  
Takashi Kikuchi ◽  
Kumiko K. Hashimoto ◽  
Atsuki Shinbori ◽  
Yuji Tsuji ◽  
Shin-Ichi Watari
Keyword(s):  
Electric Fields ◽  
Low Latitude ◽  
Low Latitude Ionosphere
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