Letter to the Editor Low-frequency electric field fluctuations and field-aligned electron beams around the edge of an auroral acceleration region

Autor: W. Miyake, R. Yoshioka, A. Matsuoka, T. Mukai, T. Nagatsuma
Jazyk: angličtina
Rok vydání: 2001
Předmět:
Zdroj: Annales Geophysicae, Vol 19, Pp 389-393 (2001)
Druh dokumentu: article
ISSN: 0992-7689
1432-0576
DOI: 10.5194/angeo-19-389-2001
Popis: Electron beams narrowly collimated to the magnetic field line were observed continuously from a down-ward current region to an auroral acceleration region (i.e., upward current region). They were well correlated with low-frequency electric field fluctuations in the auroral acceleration region as well as in the adjacent downward current region. Magnetic field fluctuations were found only in the downward current region. The analysis suggests that static field-aligned electric fields are not fully responsible for the filed-aligned electron acceleration; the ac electric field, presumably associated with Alfvenic fluctuations, should also be involved in the acceleration of ionospheric electrons.Key words. Ionosphere (particle acceleration) – Magnetospheric physics (auroral phenomena; magnetosphere-ionosphere interactions)
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