 |
| Titel |
Storm-time total electron content and its response to penetration electric fields over South America |
| VerfasserIn |
P. M. Siqueira, E. R. Paula, M. T. A. H. Muella, L. F. C. Rezende, M. A. Abdu, W. D. Gonzalez |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
0992-7689
|
| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 29, no. 10 ; Nr. 29, no. 10 (2011-10-10), S.1765-1778 |
| Datensatznummer |
250017104
|
| Publikation (Nr.) |
 copernicus.org/angeo-29-1765-2011.pdf |
|
|
|
|
|
| Zusammenfassung |
| In this work the response of the ionosphere due to the severe magnetic storm
of 7–10 November 2004 is investigated by analyzing GPS Total Electron
Content (TEC) maps constructed for the South America sector. In order to
verify the disturbed zonal electric fields in South America during the
superstorm, ionospheric vertical drift data obtained from modeling results
are used in the analysis. The vertical drifts were inferred from ΔH
magnetometer data (Jicamarca-Piura) following the methodology presented by
Anderson et al. (2004). Also used were vertical drifts measured by the
Jicamarca ISR. Data from a digisonde located at São Luís, Brazil
(2.33° S, 44.2° W, dip latitude 0.25°) are presented to
complement the Jicamarca equatorial data. Penetration electric fields were
observed by the comparison between the equatorial vertical drifts and the
Interplanetary Electric Field (IEF). The TEC maps obtained from GPS data
reflect the ionospheric response over the South America low-latitude and
equatorial region. They reveal unexpected plasma distributions and TEC
levels during the main phase of the superstorm on 7 November, which is
coincident with the local post-sunset hours. At this time an increase in the
pre-reversal enhancement was expected to develop the Equatorial Ionization
Anomaly (EIA) but we observed the absence of EIA. The results also reveal
well known characteristics of the plasma distributions on 8, 9,
and 10 November. The emphasized features are the expansion and intensification of EIA
due to prompt penetration electric fields on 9 November and the inhibition of
EIA during post-sunset hours on 7, 8, and 10 November. One important result is
that the TEC maps provided a bi-dimensional view of the ionospheric changes
offering a spatial description of the electrodynamics involved, which is an
advantage over TEC measured by isolated GPS receivers. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|