On the dynamics of large-scale traveling ionospheric disturbances over Europe on 20 November 2003
| Autor: | Claudia Borries, Daniel Kouba, Olaf Amm, Norbert Jakowski, Kirsti Kauristie, Jens Mielich |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Geomagnetic storm
TID 010504 meteorology & atmospheric sciences Total electron content Meteorology TEC Electrojet Plasmasphere ionosphere heating Space weather 01 natural sciences Navigation Geophysics Space and Planetary Science 0103 physical sciences storm Thermosphere Ionosphere 010303 astronomy & astrophysics Geology 0105 earth and related environmental sciences |
| Popis: | Ionospheric disturbances, often associated with geomagnetic storms, may cause threats to radio systems used for communication and navigation. One example is the super storm on 20th November 2003, when plenty of strong and unusual perturbations were reported. This paper reveals additional information on the dynamics in the high latitude ionosphere over Europe during this storm. Here, analyses of wavelike Travelling Ionospheric Distrubances (TIDs) over Europe are presented, based on estimates of the Total Electron Content (TEC) derived from ground-based Global Navigation Satellite System (GNSS) measurements. These TIDs are ionospheric signatures of thermospheric surges initiated by space weather events. The source region of these TIDs is characterized by enhanced spatial gradients, TEC depression, strong uplift of the F2-layer, the vicinity of the eastward auroral electrojet and strong aurora E-layers. Joule heating is identified as the most probable driver for the TIDs observed over Europe during 20th November 2003. The sudden heating of the thermosphere leads to strong changes in the pressure and thermospheric wind circulation system, which in turn generates thermospheric wind surges observed as TID signatures in the TEC. Either the dissipation of the eastward auroral electrojet or particle precipitation are considered as the source mechanism for the Joule heating.In the course of the storm, the TEC observations show a southward shift of the source region of the TIDs. These meridional dislocation effects are obviously related to a strong compression of the plasmasphere. The presented results demonstrate the complex interaction processes in the thermosphere-ionosphere-magnetosphere system during this extreme storm. |
| Databáze: | OpenAIRE |
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