Spectral Analysis of Geomagnetic Activity Indices and Solar Wind Parameters
Solar variability is widely known to affect the interplanetary space and in turn the Earth’s electromagnetical environment on the basis of common periodicities in the solar and geomagnetic activity indices. The goal of this study is twofold. Firstly, we attempt to associate modes by comparing a te...
Main Authors: | , |
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Format: | Article |
Language: | English |
Published: |
Korean Space Science Society (KSSS)
2014-06-01
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Series: | Journal of Astronomy and Space Sciences |
Subjects: | |
Online Access: | http://ocean.kisti.re.kr/downfile/volume/kosss/OJOOBS/2014/v31n2/OJOOBS_2014_v31n2_159.pdf |
Summary: | Solar variability is widely known to affect the interplanetary space and in turn the Earth’s electromagnetical environment
on the basis of common periodicities in the solar and geomagnetic activity indices. The goal of this study is twofold. Firstly,
we attempt to associate modes by comparing a temporal behavior of the power of geomagnetic activity parameters since it
is barely sufficient searching for common peaks with a similar periodicity in order to causally correlate geomagnetic activity
parameters. As a result of the wavelet transform analysis we are able to obtain information on the temporal behavior of the
power in the velocity of the solar wind, the number density of protons in the solar wind, the AE index, the Dst index, the
interplanetary magnetic field, B and its three components of the GSM coordinate system, BX, BY, BZ. Secondly, we also attempt
to search for any signatures of influence on the space environment near the Earth by inner planets orbiting around the Sun.
Our main findings are as follows: (1) Parameters we have investigated show periodicities of ~ 27 days, ~ 13.5 days, ~ 9 days.
(2) The peaks in the power spectrum of BZ appear to be split due to an unknown agent. (3) For some modes powers are not
present all the time and intervals showing high powers do not always coincide. (4) Noticeable peaks do not emerge at those
frequencies corresponding to the synodic and/or sidereal periods of Mercury and Venus, which leads us to conclude that the
Earth’s space environment is not subject to the shadow of the inner planets as suggested earlier. |
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ISSN: | 2093-5587 2093-1409 |