Abstract:

The change characteristics of magnetic storm of March 24,1991 are analyzed.This magnetic storm has different physical processes at the middle low latitudes and the southern polar cusp region.The magnetic sudden commencement is SC * and the magnetic main phase is composed of a series of the intense substorms at Zhongshan Station,Antarctica. At Beijing Ming Tombs Magnetic Observatory Center,the magnetic sudden commencement is SC ,the magnetic main phase duration is shorter and the change is bigger. This event was caused by the solar activities such as increases of the sunspot numbers, occurrence of a 3b optical flare at 22 h46 mUT on March 22,1991 and so on.