 |
| Titel |
Large scale Travelling Ionospheric Perturbations over Europe and Africa during St. Patrick’s Day storm 2015 |
| VerfasserIn |
Claudia Borries, Ayman M. Mahrous, Nada M. Ellahouny, Ronny Badeke |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250150756
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| Publikation (Nr.) |
 EGU/EGU2017-15253.pdf |
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| Zusammenfassung |
| During the intense geomagnetic storm on 17th March 2015, many GNSS applications
suffered from degradation due to strong ionospheric perturbations. Here, we are focusing
perturbations in the European-African Sector observed in the Total Electron Content (TEC).
We are analyzing wavelike phenomena considered as Large Scale Ionospheric Disturbances
(LSTID). In the European-African Sector, the storm produced three different types of LSTID:
(1) a concurrent TEC perturbation at all latitudes at the same time; (2) an equatorwards
propagating LSTID having unusually large wave parameters (wavelength: ≈3600 km, period:
≈120 min, speed: ≈500 m/s); (3) several equatorwards propagating LSTIDs with typical
wave parameters (wavelength: ≈2100 km, period: ≈60 min, speed ≈600 m/s). The
first two phenomena are rather unusual in their appearance. They occurred during
the partial recovery phase while geomagnetic perturbations were minor and IMF
turned northward. The first perturbation signature, which indicates a sudden TEC
depletion, is considered to be excited by a westward prompt penetration electric
field. Variations in the Lorentz force due to perturbed electric fields and a minor
particle precipitation effect are extracted as possible excitation mechanisms for
the second LSTID type. Third type of LSTIDs is considered to be exited as most
LSTIDs either due to variations in the Joule heating or variations in the Lorentz force. |
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