1. NASA LWS Extreme Space Weather Events II 2014 Workshop LASP, University of Colorado, Boulder July 09-11, 2014 Session 7: Campaign Events Summary

2. Speakers: Lan Jian Ying Le Gang Li Tibor Torok Dick Mewaldt Three Campaign Events: March 1989, July 2000, July 2012

3. March 1989July 2000July 2012 LocationN35E69N22W07S16W86 Peak flux (pfu)35002400035800 X-class flareX15X5X2.5 Geomagnetic effectiveness (Dst) -225-172-300 to >-1000

5. July 2000 event

6. The event exhibited non linear interaction between consecutive CMEs via a magic recipe to form a “perfect storm” extreme event, in which:  An earlier large CME should occur at the right time in order to have a minimal deceleration of the later CMEs. It should occur neither too early nor too late.  Second, the later CMEs should be launched in quick succession. They interact as close to the Sun as possible, so their expansion would be inhibited after the eruptions. The fast transit to 1 AU would significantly reduce the time for them to expand as well. Liu et al., 2014 July 2012 event

7. What is the environment that leads to such efficient particle acceleration? A special magnetic configuration leading to a two-stage eruption within a short period of time (STB, STA, SDO)

8. 2012

10. July 2000 event Flux rope eruption modeling