R. Rawat*, S. Alex and G. S. Lakhina,
Indian Institute of Geomagnetism, Plot No. 5, Sector-18, New Panvel (W),
Navi Mumbai 410 206, India
Abstract. Solar cycle-23 witnessed many successive intense X-ray solar flares and coronal mass ejections (CME) during the peak activity period, as well as in the descending phase of the cycle. Some of these emissions had large solar energetic particle events associated with them. When such solar ejecta impact the Earth's magnetosphere, they cause large scale disturbances in the geomagnetic field known as geomagnetic storms. Large variability in the occurrence characteristics of geomagnetic storms is controlled ultimately by the solar activity. Thus the changes in the interplanetary conditions are distinctly seen in the low latitude geomagnetic records as each storm event differs from the other. Several intense storm events of solar cycle-23 are analyzed for assessing the role of interplanetary magnetic field components By (east-west) and Bz (north-south) in controlling the generation and development of various types of storms.
Keywords: Sun: coronal mass ejections (CMEs)- Sun: magnetic fields - (Sun:) solar-terrestrial relations