Open AccessQuasi‐periodic poleward motions of morningside Sun‐aligned arcs: A multievent study
Author(s) -
Shiokawa K.,
Ogino T.,
Hayashi K.,
McEwen D. J.
Publication year - 1997
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/97ja02383
Subject(s) - substorm , plasma sheet , geophysics , interplanetary magnetic field , physics , geology , latitude , plasma , magnetosphere , magnetohydrodynamics , magnetic field , astrophysics , geodesy , solar wind , quantum mechanics
We study eight events of the quasi‐periodic poleward motions of Sun‐aligned auroral arcs in the high‐latitude morning sector using all‐sky image data and meridian scanning photometer data obtained at Resolute Bay (RSB; 84° magnetic latitude). Canada, during four winters from December 1992 to February 1996. More than 10% of morningside arcs observed at RSB move poleward repeatedly. The periodic arc motions occur during intervals of interplanetary magnetic field B z >0 or ∼0, B x >0 or <0, and B y >0 or ∼0. Most of the events occur around the end of substorm‐like magnetic activity, suggesting that the source of moving arcs is related to the plasma sheet particles. Comparison with a global MHD simulation suggests that the observed poleward motion of arcs corresponds to inward (+ Y GSM direction) motion of source plasmas in the morningside tail flank where the plasmas from the low‐latitude boundary layer and from the plasma sheet are mixed.