@Article{BalanTKBSSRV:2017:AuSeDs,
author = "Balan, Nalan and Tulasiram, S. and Kamide, Y. and Batista, Inez
Staciarini and Souza, Jonas Rodrigues de and Shiokawa, K. and
Rajesh, P. K. and Victor, N. J.",
affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Indian
Institute of Geomagnetism} and {Nagoya University} and {Instituto
Nacional de Pesquisas Espaciais (INPE)} and {Instituto Nacional de
Pesquisas Espaciais (INPE)} and {Nagoya University} and {National
Cheng Kung University} and {Equatorial Geophysical Research
Laboratory}",
title = "Automatic selection of Dst storms and their seasonal variations
in two versions of Dst in 50 years",
journal = "Earth, Planets and Space",
year = "2017",
volume = "69",
number = "1",
month = "Dec.",
keywords = "Energy input, Equinoctial hypothesis, Geomagnetic Dst storms, Ring
current, RM effect, Semiannual variation.",
abstract = "A computer program is developed to automatically identify the
geomagnetic storms in Dst index by applying four selection
criteria that minimize non-storm-like fluctuations. The program is
used to identify the storms in Kyoto Dst and USGS Dst in 50 years
(1958-2007). The identified storms (DstMin \≤ -50 nT) are
used to investigate their seasonal variations. It is found that
the overall seasonal variations of the storm parameters such as
occurrence, average intensity (average DstMin) and average
strength (average \〈DstMP\〉) in both versions of
Dst exhibit clear semiannual variations with equinoctial maxima
and solstice minima; and the maxima and minima in intensity and
strength (~±17% each) are less than those in occurrence (~±28%).
Wavelet spectra of the storms reveal the existence of distinct
semiannual component in four solar cycles (SCs 20-23) and weak
longer and shorter-period components in some SCs. The semiannual
variation observed also in the mean energy input during the main
phase (MP) of the storms estimated from Dst is interpreted in
terms of the (1) equinoctial mechanism based on the varying angle
between the Earth-Sun line and Earth's dipole axis and (2)
Russell-Mcpherron effect based on the varying angle between the
GSM Z-axis and GSE Y-axis; and the yearly range of the dipole tilt
angle \μ (23.2°) involved in the equinoctial mechanism is
found larger than the title angle \θ (16.3°) involved in the
RM effect.",
doi = "10.1186/s40623-017-0642-2",
url = "http://dx.doi.org/10.1186/s40623-017-0642-2",
issn = "1343-8832",
language = "en",
targetfile = "balan_automatic.pdf",
urlaccessdate = "27 abr. 2024"
}