Very intense geomagnetic storms: solar sources, characteristics and cycle distribution

SZAJKO, N.S.; CRISTIANI, G.; MANDRINI, C.H.; DAL LAGO, A.

Mendoza

Simposio; IAU Symposium 286 - Characterizing Quiet Times in the Sun and Stars; 2011

IAU

We revisit previous studies in which the characteristics of the solar and interplanetary sources of intense geomagnetic storms have been discussed. We consider the very intense geomagnetic storms that occurred during Solar Cycle 23 by setting a value of  Dstmin < -200 nT as threshold. We have identified and characterized the solar and interplanetary sources of each storm. After this, we investigate the overall characteristics of the interplanetary (IP) main-phase storm driver, including the time arrival of the shock/disturbance at 1 AU, the type of associated IP structure/ejecta, the origin of a prolonged and enhanced southward component (Bz) of the  IP field, and other characteristics related to the energy injected into the magnetosphere during the storm.