論文

査読有り
2017年10月1日

Characteristics of Seasonal Variation and Solar Activity Dependence of the Geomagnetic Solar Quiet Daily Variation

Journal of Geophysical Research: Space Physics
  • Atsuki Shinbori
  • ,
  • Yukinobu Koyama
  • ,
  • Masahito Nosé
  • ,
  • Tomoaki Hori
  • ,
  • Yuichi Otsuka

122
10
開始ページ
10
終了ページ
810
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1002/2017JA024342
出版者・発行元
Blackwell Publishing Ltd

Characteristics of seasonal variation and solar activity dependence of the X and Y components of the geomagnetic solar quiet (Sq) daily variation at Memambetsu in midlatitudes and Guam near the equator have been investigated using long-term geomagnetic field data with 1 h time resolution from 1957 to 2016. The monthly mean Sq variation in the X and Y components (Sq-X and Sq-Y) shows a clear seasonal variation and solar activity dependence. The amplitude of seasonal variation increases significantly during high solar activities and is proportional to the solar F10.7 index. The pattern of the seasonal variation is quite different between Sq-X and Sq-Y. The result of the correlation analysis between the solar F10.7 index and the Sq-X and Sq-Y shows an almost linear relationship, but the slope of the linear fitted line varies as a function of local time and month. This implies that the sensitivity of Sq-X and Sq-Y to the solar activity is different for different local times and seasons. The pattern of the local time and seasonal variations of Sq-Y at Guam shows good agreement with that of a magnetic field produced by interhemispheric field-aligned currents (FACs), which flow from the summer to winter hemispheres in the dawn and dusk sectors and from the winter to summer hemispheres in the prenoon to afternoon sectors. The direction of the interhemispheric FAC in the dusk sector is opposite to the concept of Fukushima's model.

リンク情報
DOI
https://doi.org/10.1002/2017JA024342
URL
http://orcid.org/0000-0001-5363-3870
ID情報
  • DOI : 10.1002/2017JA024342
  • ISSN : 2169-9402
  • ISSN : 2169-9380
  • ORCIDのPut Code : 37598330
  • SCOPUS ID : 85032291724

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