Persistence of Quasi-2-Day Oscillations in the Geomagnetic Activity Indices (an, as, am).

• Apostolov E.

  Geophysical Institute, Bulgarian Academy of Sciences

• Altadill D.

  Observatori de l'Ebre, CSIC, URL

• Alberca L.

  Observatori de l'Ebre, CSIC, URL

Bibliographic Information

Other Title

• Persistence of Quasi 2 Day Oscillations

Abstract

It is found that quasi-2-day oscillations persist in the geomagnetic activity indices a_n, a_s and a_m and time variations of the oscillation characteristics are examined. The 3-hourly indices for 1964-1986 are used for analysis. The main results are: 1) the oscillation persists almost continuously, 2) there are not significant hemispheric differences of the oscillation period and amplitude, 3) the dominant period is 48 hours, 4) there is expressed a semi-annual variation of the oscillation period with minimum in solstices and maximum in equinoxes, 5) the oscillation amplitude is modulated by semi-annual and long-term geomagnetic variations. A possible way for inducing such oscillations in the time variations of geomagnetic activity indices is proposed.

Journal

• Journal of geomagnetism and geoelectricity

  Journal of geomagnetism and geoelectricity 48 (10), 1233-1239, 1996

  Society of Geomagnetism and Earth, Planetary and Space Sciences

Keywords

• General Earth and Planetary Sciences
• General Environmental Science

Details

• CRID: 1390001206510872960
• NII Article ID: 10002202444
• NII Book ID: AA00698879
• DOI: 10.5636/jgg.48.1233
• ISSN: 21855765
• ISSN: 00221392
• NDL BIB ID: 4121757
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I4121757
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed