1. Sushanta C. Tripathy National Solar Observatory
Characteristics of Mode Parameters in the Source Regions of CMEs: A First Look
Sushanta C. Tripathy
National Solar Observatory

2. Outline Identification of CME source locations
Case study of 2 individual CMEs
Summary and plan for future

3. Procedure
CMEs are selected from the catalogue of Zhou et al. (2006) who have studied a total of 288 halo CMEs during and have identified their source locations by associating the events with surface activity.
CMEs are associated with extended bipolar regions, trans-equatorial magnetic loops, trans-equatorial filaments and long filaments.
We use the standard ring-diagram procedure and analyze an area of 15x15 degrees in heliographic longitude and latitude covering 128x128 pixels giving a resolution of Mm–1 or RΘ–1.
Each region is tracked for 1664 minutes
We have analyzed 44 events using the GONG+ data during within 30º of the central meridian to avoid fore-shortening effect.

5. The mode parameters of CME regions are compared with those of quiet region at the same latitude and in the same Carrington rotation to avoid errors arising from the systematic effects and foreshortening.
Compare mode Frequency, amplitude, width and total power

6. CME associated with AR NOAA 10225
CME associated with AR located at N22W12 (CR 1997, CR Long: 113º) on
First seen in C2 data at 22:06:00
Magnetic activity Index (MAI): 97.6 Gauss
No Flare observed
Quiet region at same position on (CR Long 204) and MAI 2.7 Gauss

7. CME source location: N22W12

8. Active Region NOAA 9628
Location: S22.5 E15 (CR Long: 292.5) on 23 March 2001
MAI Gauss
Compared with a quiet region at same latitude and at 0º longitude on 16 March 2001 with a MAI of 0.08 Gauss (CR Long: 45º)

9. Comparison of 2 quiet regions

10. Relative frequency differencesP1 P2 p3
CME region
Active Region
Av. error in each point
3.5 mHz ~ 10-4 μHz
4.5 mHz ~ 10-3 μHz

11. Ratio of the peak power CME region Active Region f P1 P2 p3
Av. error in each point
3.5 mHz ~ 0.05
4.5 mHz ~ 0.12

12. From Rajaguru, Basu, & Antia (2001)

13. Relative difference in half-widthP1 P2 p3
CME region
Active Region
Av. error in each point
3.5 mHz ~ 0.07
4.5 mHz ~ 0.13

15. Relative difference in total power
CME region
Active Region

16. CME associated with a Filament
CME associated with filament located at S25W18 (CR 1986, CR Long:231º)
First seen in C2 data on at 02:30
MAI: 11.3 Gauss
Quiet region at CR Long 169º (020217), MAI 3.7

17. Relative frequency differencesP1 P2 p3
CME region
Active Region

18. Ratio of the amplitudes
A / A (Quiet)
CME region
Active Region f P1 P2 p3

19. Relative differences in half-widthP1 P2 p3
CME region
Active Region

20. Ratio of the mode area A*Γ / A*Γ (Quiet) CME region Active Region f P1

21. Temporal evolution of line-width in AR and CME regions

25. CME1: N22 w12
CME2: S25w18

30. f-modes: 2550 to 2750 μ Hz
p-modes μ Hz

31. Summary
The widths of the peaks is a function of the frequency and the radial order ‘n’. For most CMEs, the widths are smaller implying longer life times.
The f- and p-mode frequencies of high degree modes are significantly larger compared to quiet regions if the CME is in active region.
The power in both f- and p-modes is lower in CME regions
The increase in mode frequency is monotonic in frequency while all other properties show more complex frequency dependence.

32. Areas for Further Study
Look at ring diagrams produced over shorter time spans and/or smaller patches to isolate more transient features.
Look at magnetograms to see how MAI changes day-to-day to see if this explains daily variations
Look at flow maps and other fluid descriptors.
MORE STATISTICS