On the Solar Origins of Intense Geomagnetic Storms Observed During 6-11 March 1993
Abstract
Intense geomagnetic storms with DST index <= -100nT were recorded on 9March and 11March 1993 associated with solar activity on 6March and 9-10March, respectively. In this paper, we discuss the characteristic features of the solar origins of the two events that gave rise to coronal and interplanetary disturbances and as a consequence produced strong geomagnetic activity at the Earth. The source of the activity in one case is attributed to a major 3M7.0 flare that occurred on 6March 1993 and in the other case, to two large filament disruptions on the disk during 9-10March, 1993. Both these sources were found to be located near changing or varying low-latitude coronal holes. They were also located close to the heliospheric currents sheets. Distinct X-ray activity was observed for both the events as observed by the Yohkoh SXT telescope. The detailed evolution and a comparison of these events on the basis of Yohkoh soft X-ray observations are presented here.
- Publication:
-
Solar Physics
- Pub Date:
- December 1998
- DOI:
- 10.1023/A:1005018328191
- Bibcode:
- 1998SoPh..183..419S