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Indian Journal of Radio & Space Physics (IJRSP) >
IJRSP Vol.39 [2010] >
IJRSP Vol.39(5) [October 2010] >
| Title: | Study of geomagnetic storms with Dst < -100 nT during 1999 – 2002 |
| Authors: | Kumar, Santosh
Raizada, Amita |
| Keywords: | Coronal mass ejection (CME)
Solar flare (SF)
Active prominences and disappearing filament (APDF)
Interplanetary magnetic field (IMF)
Geomagnetic storm (GMS) |
| Issue Date: | Oct-2010 |
| Publisher: | NISCAIR-CSIR, India |
| PACS No.: | 94.30.Lr; 96.60.ph; 94.20.Vv |
| Abstract: | Ninety geomagnetic storms (GMSs) of intense
nature, i.e. with Dst <-100 nT have been noticed using solar geophysical
and interplanetary data during solar cycle 23. Out of which, 36 GMSs of intense
(-200 nT ≤ Dst < -100 nT) nature and 10 of super intense (Dst < -200 nT)
nature have occurred during the maximum phase, i.e. from 1999 to 2002, of solar
cycle 23. The variation in time delay between the commencement and peak time of
GMS is observed to be 5.5 to 42.5 h for different storms. The strength of GMS
does not reveal any dependence with the duration of the storm as well as with
the number of CMEs involved in the occurrence of storm. The high speed solar
wind plasma, may be in the form of CMEs or else, is more likely to cause the
intense and super intense GMSs. The solar features, i.e. X-ray solar flares
(SFs), active prominences and disappearing filaments (APDFs), coronal mass
ejections (CMEs), etc. responsible for causing GMSs have been studied. The
geo-effective CMEs show longitudinal as well as hemispherical bias.
Geo-effective CMEs causing intense and super intense GMSs are mostly confined
between ±30° latitude and ±40° longitude. The correlation coefficients of 0.71
and 0.66, respectively of Bz and Vsw.Bz with Dst index indicates that Bz and
Vsw.Bz may be considered as key contributors in determining the strength of
GMSs. |
| Page(s): | 284-289 |
| CC License: |  CC Attribution-Noncommercial-No Derivative Works 2.5 India |
| ISSN: | 0975-105X (Online); 0367-8393 (Print) |
| Source: | IJRSP Vol.39(5) [October 2010]
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