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Asymmetric Development of Auroral Surges in the Northern and Southern Hemispheres
Author(s) -
Uchida H. A.,
Kataoka R.,
Kadokura A.,
Murase K.,
Yukimatu A. S.,
Miyoshi Y.,
Shiokawa K.,
Ebihara Y.,
Hosokawa K.,
Matsuoka A.,
Kurita S.,
Fujita S.,
Shinohara I.
Publication year - 2020
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2020gl088750
Subject(s) - earth's magnetic field , northern hemisphere , geology , southern hemisphere , surge , asymmetry , ionosphere , geophysics , climatology , geodesy , magnetic field , physics , geomorphology , quantum mechanics
Simultaneous eastward and westward traveling surges were observed at Tjörnes, Iceland, and Syowa station, Antarctica, respectively. Several remarkable differences were identified. (1) The position of the initial bright spot was shifted by 1.7 to 2.3 MLT between both hemispheres. (2) The surges differ in traveling speed between the eastward traveling surge (6.5 km s −1 ) and the westward traveling surge (1.3 km s −1 ). (3) The Arase satellite was located on a geomagnetic field line connecting both ground stations and observed a significant excess in westward component of the magnetic field, which is consistent with the large shifts of the initial bright spots in both hemispheres. (4) The background Hall current flows eastward (Northern Hemisphere) and westward (Southern Hemisphere). The observed north‐south asymmetry of the traveling surges suggests that the ionosphere can play an essential role in controlling the fundamental spatiotemporal development of auroras in both hemispheres.