1. Pietro Zucca, Eoin Carley, Shaun Bloomfield, Peter Gallagher
Trinity College Dublin
The formation heights of CME-driven shocks using empirical Alfvén maps of the solar corona
Pietro Zucca,
Eoin Carley, Shaun Bloomfield, Peter Gallagher
School of Physics, Trinity College Dublin, Ireland

2. Overview Shocks in the solar corona and their radio signature
Density and Alfvén speed of the solar corona
Study of 2011 September 22 Type II radio burst
Results and conclusions

3. Type II radio burst Plasma Emission Shock Condition
Rosse Solar Terrestrial Observatory (RSTO; Zucca et al. 2012)

4. From density to height
(ne,t)
ne(r) model
(r,t)
2 orders of magnitude

5. Alfvén Speed
Mann et al. 2002

6. Alfvén Speed 2D Model
Warmuth et al. (2005)

7. Density Map with SDO/AIA and SOHO/LASCO
B-Field with PSFF
Density Map with SDO/AIA and SOHO/LASCO

8. Emission Measure 18 19 20 21 22 23
Aschwanden et al. (2011)

9. Emission Measure to Density
The density can be estimated if we know the LOS length S(x,y)
Menzel (1936)

10. Density with SOHO/LASCO
Hayes et al. (2001)

11. Density Models SDO/AIA data Spherical Symmetric Solution
Combined Model
SOHO/LASCO data
Plane Parallel Solution

12. Polar density Map SDO/AIA 1-1.3 R Model 1.3 - 2.5 R SOHO/LASCO
Electron Density [cm-3]

13. Density / Position Angle

14. Electron Density Map
LASCO
2.5 R
MODEL
1.3 R
SDO

15. Magnetic Field zuccap@tcd.ie Magnetic field [Gauss] 0.1 0.5 2.5 15 90
500
Magnetic field [Gauss]

16. Alfvén Speed Map zuccap@tcd.ie 2 RSun Zucca et al. 2013, A&A in prep
150
300
600
1250
2500
5000
2 RSun
Zucca et al. 2013, A&A in prep

17. Study of 2011 Sep 22 Type II radio burst
Using the 2D density and Alfvén maps

18. CME eruption

19. Non-radial kinematics
EUV Height time
Type II Height Time

20. Height-time comparison
EUV propagating feature
Type II radio burst

21. Matching Kinematics
90-70 MHz

22. Matching Kinematics
150 MHz

23. Matching Kinematics
150 MHz
150 MHz from NRH

24. Alfven Speed

25. Matching Kinematics
90-70 MHz

26. Conclusions 2D density and Alfvén maps
Non-radial study of Type II burst – CME
Shock formed in the ‘Upper-flank’ region