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Title: The interplanetary magnetic field B sub y -dependent field-aligned current in the dayside polar cap under quiet conditions

Abstract

Spatial distribution and temporal variation of the interplanetary magnetic field (IMF) B{sub y}-dependent cusp region field-aligned currents (FACs) during quiet periods were studied by use of magnetic data observed by Magsat. The analysis was made for 11 events (each event lasts more than one and a half days) when the IMF B{sub y} component was steadily large and B{sub x} was relatively small ({vert bar}B{sub z}{vert bar} < {vert bar}B{sub y}{vert bar}). Results of the analysis of total 62 half-day periods for the IMF B{sub y}-dependent cusp region FAC are summarized as follows: (1) the IMF B{sub y}-dependent cusp region FAC is located at around 86{degree}-87{degree} invariant latitude local noon, which is more poleward than the location of the IMF B{sub z}-dependent cusp region FAC; (2) the current density of this FAC is greater than previous studies ({ge} 4 {mu}A/m{sup 2} for IMF B{sub y} = 6 nT); (3) there are two time scales for the IMF B{sub y}-dependent cusp region FAC to appear: the initial rise of the current is on a short time scale, {approximately} 10 min, and it is followed by a gradual increase on a time scale of several hours to a half day; (4) themore » seasonal change of this FAC is greater than that of the nightside region 1 or region 2 FACs; (5) the IMF B{sub z}-dependent cusp region FAC is not well observed around the cusp when the IMF B{sub y}-dependent cusp region FAC is intense.« less

Authors:
 [1];  [2]
  1. Univ. of Alaska, Fairbanks (USA) Kyoto Univ. (Japan)
  2. Kyoto Univ. (Japan)
Publication Date:
OSTI Identifier:
5839089
Resource Type:
Journal Article
Journal Name:
Journal of Geophysical Research; (USA)
Additional Journal Information:
Journal Volume: 94:A3; Journal ID: ISSN 0148-0227
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; POLAR CUSP; ELECTRIC CURRENTS; AURORAL ZONES; CURRENT DENSITY; DATA ANALYSIS; INTERPLANETARY MAGNETIC FIELDS; MAGNETOMETERS; POLAR REGIONS; SEASONAL VARIATIONS; SPATIAL DISTRIBUTION; CURRENTS; DISTRIBUTION; MAGNETIC FIELDS; MEASURING INSTRUMENTS; VARIATIONS; 640201* - Atmospheric Physics- Auroral, Ionospheric, & Magetospheric Phenomena

Citation Formats

Yamauchi, M, and Araki, T. The interplanetary magnetic field B sub y -dependent field-aligned current in the dayside polar cap under quiet conditions. United States: N. p., 1989. Web. doi:10.1029/JA094iA03p02684.
Yamauchi, M, & Araki, T. The interplanetary magnetic field B sub y -dependent field-aligned current in the dayside polar cap under quiet conditions. United States. https://doi.org/10.1029/JA094iA03p02684
Yamauchi, M, and Araki, T. 1989. "The interplanetary magnetic field B sub y -dependent field-aligned current in the dayside polar cap under quiet conditions". United States. https://doi.org/10.1029/JA094iA03p02684.
@article{osti_5839089,
title = {The interplanetary magnetic field B sub y -dependent field-aligned current in the dayside polar cap under quiet conditions},
author = {Yamauchi, M and Araki, T},
abstractNote = {Spatial distribution and temporal variation of the interplanetary magnetic field (IMF) B{sub y}-dependent cusp region field-aligned currents (FACs) during quiet periods were studied by use of magnetic data observed by Magsat. The analysis was made for 11 events (each event lasts more than one and a half days) when the IMF B{sub y} component was steadily large and B{sub x} was relatively small ({vert bar}B{sub z}{vert bar} < {vert bar}B{sub y}{vert bar}). Results of the analysis of total 62 half-day periods for the IMF B{sub y}-dependent cusp region FAC are summarized as follows: (1) the IMF B{sub y}-dependent cusp region FAC is located at around 86{degree}-87{degree} invariant latitude local noon, which is more poleward than the location of the IMF B{sub z}-dependent cusp region FAC; (2) the current density of this FAC is greater than previous studies ({ge} 4 {mu}A/m{sup 2} for IMF B{sub y} = 6 nT); (3) there are two time scales for the IMF B{sub y}-dependent cusp region FAC to appear: the initial rise of the current is on a short time scale, {approximately} 10 min, and it is followed by a gradual increase on a time scale of several hours to a half day; (4) the seasonal change of this FAC is greater than that of the nightside region 1 or region 2 FACs; (5) the IMF B{sub z}-dependent cusp region FAC is not well observed around the cusp when the IMF B{sub y}-dependent cusp region FAC is intense.},
doi = {10.1029/JA094iA03p02684},
url = {https://www.osti.gov/biblio/5839089}, journal = {Journal of Geophysical Research; (USA)},
issn = {0148-0227},
number = ,
volume = 94:A3,
place = {United States},
year = {Wed Mar 01 00:00:00 EST 1989},
month = {Wed Mar 01 00:00:00 EST 1989}
}