1. Coronal and interplanetary radio emission as a tracer of solar energetic particle propagation
Karl-Ludwig Klein
(F Meudon)

2. Outline of this contribution
PFSS calculations of coronal field lines and comparison with type III burst imaging: field-aligned coronal transport of impulsive SEP.
Failure of the PFSS model ? The case of the heliolatitudinal connection.
Radio imaging of the origins of impulsive SEP on 2008 Nov 04 and 2009 May 01.

3. The coronal magnetic field and SEP transport
Radio observations and magnetic field extrapolations.

4. Type III bursts and PFSS extrapolations as tracers of open flux tubes in the corona
SoHO/COSTEP
Klein & Posner 2005 A&A 438, 1029
215 RS
4 RS
Solar release time of energetic particles (p 5-55 MeV, SoHO/COSTEP; e keV, Wind/3DP) from energy dispersion of onset times.
Events accompanied by type III bursts (e- beams 10 keV)
Track radio emission to 1 AU (ground + Wind/WAVES)
m- maps at several  - sections of open flux tube at several altitudes in the corona (Nançay Radioheliograph).
Compare with potential magnetic field extrapolations (SolarSoft; Schrijver & DeRosa).
Type III sources
164 MHz
237 MHz
327 MHz

5. View from above solar north
Type III bursts as tracers of particle propagation in the coronal and IP magnetic field: longitude
Impulsive SEP accompanied by m- type III bursts (e- beams 10 keV)
Type III maps (solar corona; Nançay RH) & potential field extrapolations (Schrijver & DeRosa): e- beams reveal rapidly diverging open flux tubes (factor low corona / 2.5 RS)
Magnetic connection to Earth in simple (impulsive) SEP events even when parent AR up to 50° away from the nominal Parker spiral !
Large IP injection cones possible even from acceleration sites in an active region - no large scale accelerator needed.
327 MHz
237 MHz
164 MHz
2000 May 01
237 MHz
164 MHz
151 MHz
2003 Oct 04
Klein, Krucker, Lointier, Kerdraon 2008, A&A 486, 589
View from above solar north
Parker spiral

6. Failure of the PFSS model ?
Our study: the PFSS model seems to provide an adequate description of the coronal magnetic field correction between the parent AR and the nominal connection longitude on the source surface. Validation by the comparison with type III radio sources.
Others (Nitta & Derosa 2008 ApJ 673, L207; Rust et al ApJ 687, 635): PFSS model fails in a significant number of cases - open field lines rooted in the AR may not lead from the parent AR to the root of the nominal Parker spiral connected to the ecliptic plane.

7. Failure of the PFSS model ? An example:
237 MHz
164 MHz
2002 Dec 12
Wang et al ApJ 639, 495
Particle propagation to high heliolatitudes : how can these particles be detected in the ecliptic plane near 1 AU ?
PFSS field lines through the radio source (green) do not connect to the ecliptic.
Type III at s/c accompanied by Langmuir waves (e- beam intercepted by s/c).
Type III emitting electrons travel to high latitude in the corona, but are in the ecliptic at 1 AU  IP field line curves down to the ecliptic before reaching 1 AU ( Parker).
The failure is due to the Parker model, not to the PFSS extrapolation !

8. The 2008 Nov 04 impulsive SEP event
DOY 308 = Nov 04
Courtesy B. Klecker;
Wiedenbeck et al. ICRC 2009

9. 2008 November 4 SEP event: 2 electron injections at all three s/c
SWAVES/STEREO: two successive DH III
Weak impulsive SEP
SXR burst, peak 03:17 (after Mason et al. 2009; is this consistent with the following ???)
H flare: SF, start 03:26, max 03:29, N35 W38 (LEAR/SGD)
Type III 03:22-03:36, 160 MHz (different obs / SGD)
Weak microwave burst (NoRP 2 GHz)
No imaging observations (NRH), but SWAVES shows similar radio events later on Nov 04

10. 2008 November 4 NRH 150 MHz: weak noise storm
NRH 432 MHz: very weak noise storm; CH near disk centre

11. 2008 Nov 04 10:26 (multiple electron injections)

12. 2008 November 3 & 4: noise storm sources
NRH: multi-wavelength snapshots of m- noise storm on 2008 Nov 03 (left) and 04 (right): essentially the same source configuration (different colours - to be changed). Expected to be one leg of a large-scale loop system.

13. 2008 November 4: PFSS and radio sources
NRH/PFSS: m- noise storm in a large-scale loop system extending SW ward from leading part of AR. This loop system must open at some altitude. The long m- and DH III bursts suggest indeed that open field lines exist above the noise storm source.
 Fearless field line drawing.

14. 2008 November 4: PFSS and radio sources
Comparison with the extrapolations of Mason et al. (2009; yellow: to the ecliptic). Check the polarities of the hand-drawn field lines.

15. 2009 May 1

16. 2009 May 1
Followed by a
continuum (?)
Bursts followed by long duration emission (continuum or dense series of bursts) - observed by NRH at
151, 228, 299 MHz
Initial weak bursts at times of type III (SGD, <60 MHz; Wind/WAVES)
Bursts at time
of type III<60 MHz

17. 2009 May 01: PFSS field lines and radio sources
Open flux tube (type III) curved towards the observer above closed PFSS field lines.

18. Radio astronomical constraints on energetic particle propagation in the corona
The radio emission of electron beams (« type III bursts ») can be used as tracer of open coronal magnetic flux tubes.
Type III bursts and magnetic field extrapolations show that
open magnetic field lines rooted in small parts of AR diverge rapidly with height and can easily cover 90° in solar longitude;
strongly curved open field lines connect solar active regions to the nominal Earth-connected Parker spiral even when the parent active region is several tens of degrees away in longitude.
Type III bursts and Langmuir waves in situ imply that the interplanetary field lines may curve downward (Parker)
2008 November 04 and 2009 May 01:
Type III bursts at long m-; from high coronal sources;
2008 Nov 04: noise storm at shorter m-, closed coronal structures at that height (within 0.5 R)
Type III at greater altitude; open flux tubes, streamer-like configuration
Similar 2009 May 01 ?