Observation of field-aligned and ionospheric currents during space weather month, September 1999
| Autor: | Peter Stauning, V.A Popov, V. O. Papitashvili, O. Rasmussen, Jurgen Watermann, Jeffrey P. Thayer |
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| Rok vydání: | 2002 |
| Předmět: |
Geomagnetic storm
Atmospheric Science Incoherent scatter Aerospace Engineering Astronomy and Astrophysics Space weather Atmospheric sciences Bow shocks in astrophysics Geodesy Physics::Geophysics Latitude Solar wind Geophysics Space and Planetary Science Physics::Space Physics General Earth and Planetary Sciences Astrophysics::Earth and Planetary Astrophysics Ionosphere Interplanetary magnetic field Physics::Atmospheric and Oceanic Physics Geology |
| Zdroj: | Advances in Space Research. 30:2203-2208 |
| ISSN: | 0273-1177 |
| Popis: | September 1999 was a magnetically active month, with several geomagnetic storms occurring in sequence which influenced the current pattern of the high-latitude ionosphere. The DMI Greenland magnetometers recorded variations of the ionospheric Hall currents while Orsted, a Danish low-altitude Earth-orbiting satellite, measured the magnetic effect of field-aligned currents (FAC). We discuss a particular dayside event which occurred a few hours after the peak of a moderate storm on Sept. 15, 1999. Orsted proceeded polebound on a trajectory closely aligned with the Greenland west coast magnetometer chain, and the Sondrestrom Incoherent Scatter Radar was in operation scanning the ionosphere almost parallel to the Osted trajectory. Coincident solar wind (SW) and interplanetary magnetic field (IMF) data were obtained from the ACE spacecraft and ballistically propagated to a nominal subsolar bow shock location at 12 Re. A synoptic view of the data suggests that the dayside field-aligned and ionospheric current system responded quickly (within 5–10 min) to variations of the northward component of the IMF (IMF- Bz). Specifically, the latitude of the boundary between westward and eastward high-latitude Hall currents as well as the latitudes of the maxima of the eastward and westward currents followed closely IMF-Bz variations. |
| Databáze: | OpenAIRE |
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