Global ULF disturbances during a stormtime substorm on 25 September 1998
| Autor: | J. M. Ruohoniemi, Kristian Schlegel, V. I. Taran, A. P. Potekhin, John C. Foster, R. H. W. Friedel, Evgeny Mishin, Frederick J. Rich, K. Yumoto |
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| Rok vydání: | 2002 |
| Předmět: |
Atmospheric Science
Incoherent scatter Soil Science Aquatic Science Oceanography Physics::Geophysics Geochemistry and Petrology Substorm Earth and Planetary Sciences (miscellaneous) Interplanetary magnetic field Physics::Atmospheric and Oceanic Physics Ring current Earth-Surface Processes Water Science and Technology Physics Ecology Paleontology Forestry Geophysics Solar wind Space and Planetary Science Middle latitudes Local time Physics::Space Physics Ionosphere |
| Zdroj: | Journal of Geophysical Research: Space Physics. 107:SMP 40-1 |
| ISSN: | 0148-0227 |
| DOI: | 10.1029/2002ja009302 |
| Popis: | [1] Quasiperiodic perturbations of ionospheric plasma with ∼10 min occurrence periods were observed by incoherent scatter radars (ISR) in high-latitude and midlatitude ionosphere after the onset of a stormtime substorm. The latter occurred during a period of complex dynamical activity and had a number of unusual characteristics. The perturbations indicate ultralow frequency (ULF) electric field enhancements over the Northern Hemisphere. Specifically, strong subauroral electric fields are associated with the ring current-related polarization jet (PJ). These perturbations correlate with magnetic variations in high-latitude and midlatitude regions spanning ∼21 hours in magnetic local time (MLT). The radar and ground magnetometer data are supported by simultaneous observations from the DMSP and geostationary satellites. As a result of the onset, the preexisting PJ shifted equatorward to L ∼ 2.5. Similar periodicities in the solar wind dynamic pressure and interplanetary magnetic field (IMF) appear to be natural sources of the ULF perturbations observed at high and middle latitudes. |
| Databáze: | OpenAIRE |
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