Solar Magnetic Polarity Dependence of the Seasonal Occurrence of Geomagnetic Storms
Abstract
To investigate the seasonal variation and its solar magnetic polarity dependence of geomagnetic activity, we performed the statistical analysis on the geomagnetic storms defined by Dst index. We used storm data for 5 years each at solar minimums during the 4 solar cycles 19 to 22 (1962-1998) for even two of each solar magnetic polarities. We selected total 156 geomagnetic storms of Dst(min) < -50 nT, |Dst| > 100 nT and compared the monthly occurrence of those storms. The geomagnetic storms occurred more frequently in spring and fall seasons for all solar cycle minimums regardless of the solar magnetic polarity. It is in the summer and winter seasons that the geomagnetic storm occurrence rate increased more for the solar cycles 20 and 22 when the solar magnetic polarity is anti-parallel to the Earth's than the solar cycles 19 and 21.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2008
- Bibcode:
- 2008AGUFMSH21B1604O
- Keywords:
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- 2134 Interplanetary magnetic fields;
- 2162 Solar cycle variations (7536);
- 2784 Solar wind/magnetosphere interactions;
- 2788 Magnetic storms and substorms (7954);
- 7954 Magnetic storms (2788)