Analysis of the Dst-index Based Temporal Profile of the Severe Geomagnetic Storms of Solar Cycles 23 and 24

Abstract This work analyzes the severe storms of solar cycles 23 and 24 from the temporal profile of the storms based on Dst-index. Sixteen severe storms (Dst<-200nT), have been identified in the two solar cycles. The study reveals the occurrence of two severe storms in 1998, one severe storm in 1999, four severe storms in 2000, three severe storms in 2001, two severe storms in 2003, two severe storms in 2004, one severe storm in 2005 and one severe storm in 2015. There are four double storms in the solar cycles in the durations: 06–08 April, 2000, 31 March – 01 April, 2001, 29–31 October, 2003, and 07–11, November, 2004. The least severe storm is observed to have a Dst-index of -207nT on 04 May, 1998 at about 05:00 UT. The most severe storm is seen to have a Dst-index of -387nT on 31 March, 2001 at nearly 08:00 UT. This work is important because of the adverse effects of storms on satellites and telecommunication systems.