On the source of the super-storm of solar-cycle # 23 associated with the solar flares on 18 November 2003

Abstract

We study the solar source of intense geomagnetic storm of solar cycle 23 occurred on 20 November 2003. The flare/CME responsible for the geomagnetic storm originated from the super-active region NOAA 10501. We investigate the Hα observations of the flare event made with 15 cm Solar Tower Telescope at ARIES, Nainital, India. The propagation characteristics of the CME have been obtained from the three-dimensional images of the solar wind obtained from the interplanetary scintillation technique, supplemented with the other ground and space-based missions. It is inferred that two CMEs were originated from the same filament channel at the active region and their interaction along the Sun–Earth line has led to the severity of the storm. According to our investigation, the interplanetary medium consists of two merging magnetic clouds (MCs) that preserve their identity during their propagation. These magnetic clouds make the IMF southward for a long time, resulting the super-storm on the Earth.