1. CME Interactions and Particle Acceleration N. Gopalswamy (NASA/GSFC) 2003 February 11 Elmau CME workshop, Group-C Presentation (B. Klecker’s Group)

2. In this talk… Broadband radio signatures due to successive CMEs (electrons) SEP intensity and preceding wide CMEs  More details: ApJ, 548, L91, 2001 ApJ, 572, L103, 2002 GRL 29(8), 106-1, 2002 SW10 Proceedings, 2002 GRL 2003 in press

3. Interacting CMEs Distinct radio signatures: electron acceleration -Broadband enhancement following type II (ApJ, 548, L91, 2001) -Radio enhancement with nothing before interaction -Deviation from normal type II spectrum Implications to SEPs: -Particles need to escape from region of interaction -Magnetic connectivity to Earth - SEP production and modification of acceleration

4. The two CMEs are indistinguishable at 23:42 UT 830 km/s (S07E40) 1460 km/s (S07E46) ~200%

5. 20010120 CMEs Two fast CMEs from the same region (AR 9313), two hours apart Both driving shocks Intense radio emission following the second The second CME “sees” a different corona, viz, the first CME EIT 195 movie showing the source of the two fast CMEs

6. CME Interaction & SEPs: Statistics PropertyMajor (>10pfu)Minor (1-10 pfu) Total #4339 Avg Speed km/s 1393927 Width >100 deg98% (41/42)87% (34/39) CME Interaction83% (35/42)87% (34/39) All Interactions93% (39/42)97% (38/39) Assoc.w/DH II95% (40/42)56% (22/39) Onset time Diff6.9 hrs7.1 hrs Intersec. Height21 Ro Avg PA overlap50 deg52 deg Gopalswamy et al., 2002 ApJ, 573, L103

7. Inverse Study: Fast &Wide CMEs 52 fast (> 900km/s) & Wide (> 60deg) frontside, western hemispheric CMEs. Look for SEP events. No SEPSEP No Interaction42 (7) Interaction640 (35) CME Interaction discriminates SEP-poor from SEP-rich Marginal overlap ~10 deg Including streamer interaction Minor

8. Preconditioning SEP intensity (I) is correlated with CME velocity (V): I varies over 4 orders of magnitude, while V is in the range 500-2500 km/s [Kahler, 2001] Kahler considered ambient level of SEP intensity as one of the factors responsible for the scatter We consider preceding wide events – consistent with Kahler’s result but the effects are more than providing seed particles

9. Two Nearby Fast Eruptions

10. SEP Intensities CME 2 S15W34 1450 km/s CME1 S25W67 1450 km/s 1 2 P

11. WAVES type IIs CME1CME2 II-1 II-2

12. Continued to lower frequencies as one of the most spectacular IP type IIs

13. Preconditioning: High SEP intensity results when preceded by a wide CME S16W71 9415 17:54 830 km/s S20W85 9415 14:06 1200 km/s

14. Type IIIs similar

15. SEP Intensities: Coronal/IP environment matters? Intensity Level With Prewide Without Prewide Total High >50 pfu 17 (65%)9 (35%)26 Low < 50 pfu 3 (15%)17 (85%)20 Divide SEP events into high & low int. events Look for preceding fast & wide events within a day from the same AR There seems to be a tendency for the high intensity events to be preceded by wide events

16. Preconditioning: Influence of Preceding Wide CMEs on SEP Intensity Out of the 46 major SEP events of this cycle -26 were of high intensity (I > 50 pfu) -20 were of low intensity (10 pfu < I < 50 pfu) -Look for wide (>60 deg) CMEs within a day ahead of the SEP events. The average preceding time was found to be ~11 hrs 17/26 (65%) high-intensity events and only 3/20 (15%) low- intensity events were preceded by a wide event within a day -modification of the streaming limit? -Temporary quasiparallel geometry? 37/47 (79%) events had enhanced background (Kahler 2001 found a weak correlation between SEP intensity and ambient level of SEPs)

17. Complexity of Solar Eruptions Nat Gopalswamy, NASA GSFC, Greenbelt, MD Topics to be discussed CME-CME interactions Radio Signatures (Energetic Electrons) Solar Energetic Particles More details: ApJ, 548, L91, 2001 ApJ, 572, L103, 2002 GRL 29(8), 106-1, 2002 SW10 Proceedings http://cdaw.gsfc.nasa.gov/LWS/ SHINE meeting Invited talk Plenary session August 19 2002 Banff