Solar radio emission at solar maximum

1. Solar radio emission at solar maximum CME development in the corona M. Pick, D. Maia and Ch. Marqué LESIA, Observatoire de Paris Cospar 2002

2. Context • Nançay Radioheliograph (NRH) • Multiwavelength observations (dm-m) • High cadence < second • Radio survey • NRH and WAVES/WIND spectrograph (dam-km) • Use for many objectives • Coordinated observations • SOHO, TRACE, ACE, WIND, YOHKOH, Ulysse and Ground facilities (Halpha and radio) • Interest of disk observations

3. Context • Flare/CME events • Non thermal emission • Energetic electrons tracers of B field • Search for weak emission often occulted by NT emission • CMEs in the absence of large flares • Association with noise storms (NT emission) • Thermal emission and eruptive prominences Radio signatures

4. CME lateral expansion Fast progression in latitude Full extend: 9 min ≥1000 km/s Successive loop interactions Super-alfvenic disturbance Maia et al., 1999

5. Full expansion < 10 min. Signatures of these interactions step by step. Follow in space and time CME progression November 06 1997 Maia et al., 1999

6. On-disk event Moreton wave coronal shock wave M-type IIAssociation in time and space Pohjolainen et al., 2001

7. Bastille event Full expansion 15 min. Maia et al. 2001

8. Proxies of CMEs • Lateral progression of CME development in the early stage • Full development reached within 10 min. or often less • Similar shape seen by NRH-LASCO(Gopalswamy and Kundu,1992) • Identification of different scenarios • Starting point :study of individual events

9. Other class of CME development South part of the CME: Breakout type instability Null point 26OOO km, B reconnection, MHD wave triggers activity. S Loops pushing up and interconnecting with multiple B systems. North part of the CME (F sources): Null points western part 6000km Cospatial south loops East and West Quasi simultaneous Coronal null point Maia, Aulanier, S. J. Wang et al., 2002

10. Radio signature of B reconfiguration October 25, 2000

11. Dynamics of CMEs: Detection of weak NT emissions Bastian et al., 2001: « Radio CME » Maia et al., 2001Plasma front , CME-Driven shock

12. C2 NRH • Gyrosynchrotron emission • Radio V 1570 ± 390 km/s • LASCO V 980± 70 km/s • Deacceleration in the corona <4 Rs • (Gopalswamy et al., 02) C3 C2

13. Thermal emission and CME development Type III like bursts above the parasitic polarity Radio depression appears ~40 mn later Dynamical continuity radio depression and CME substructures Marqué et al., 2002

14. Continuity with radio depression CAVITY • On-disk and limb observations • Traces the motion at low altitude • Link between EIT and LASCO

15. CONCLUSION • Multifrequency radio imaging observations • On-disk and limb behaviour of CME • Link with coronographic observations • Perspective :systematic studies using the survey CMEs, origin of energetic electron events… • Limitations • Need of high dynamic range • Hardly difficult to observe both weak and strong emission • Presently No sufficient frequency coverage • NEED for FASR

16. Narrow band horizontal features (Reiner et al;, 2000)

18. DATA ANALYSISCoronal and IP Radio signatures • Wide spectral coverage • Radio source (dm-m) • 5 /11events: complex evolution (spectral, spatial and temporal) WIND DAM 09:28 NRH 18 February 2000

19. Radio signatures and CME NRH: 09:19 UT + DAM • Source of electrons in region of interaction, • First shock is the triggering agent • Importance of the wide spectral range (Klassen, 01)

20. Role of Moreton wave in flare/CME development • Moreton wave and coronal m-type II burst • Subsequent B interaction Observations: agreement with P.F. Chen et al. (2002) Piston-driven shock along envelope of CME Legs Moreton wave Moving wave-like (enhanced plasma region ahead) EIT wave succesive opening of B (Delannée et al., 99)

23. Role of Moreton wave in flare/CME development Flare/CME events involving multi-magnetic structures Full expansion < 10 min. Moreton waves: causal association with CMEs : lateral expansion BUT NOT ALWAYS Maia et al., 1999; Maia et al, 2001

29. Moreton waves and Flare/CME events East and West Quasi simultaneous F A D E C Cospatial south loops Complex of activity Filament eruption Moreton wave, 1400 km/s

30. Moreton waves and Flare/CME events South part of the CME:Breakout type instability Null point 26OOO km, B reconnection, MHD wave triggers activity. S Loops pushing up and interconnecting with multiple B systems. North part of the CME (F sources): Null points western part 6000km Alternatively, shock but no evidence in the north part Moreton wave and eruptive prominence no significant role

31. October 14 1999 Maia, Aulanier, S. J. Wang et al., 2002

33. Radio event • Faint type III-like bursts above the parasitic polarity: beginning of the eruption in EIT (slow evolution phase). • Radio depression to appear ~40 mn later (acceleration phase) • Dynamical continuity between radio depression and CME substructures.

35. South part of the CME: Breakout type instability Null point 26OOO km, B reconnection, MHD wave triggers activity. S Loops pushing up and interconnecting with multiple B systems. F North part of the CME (F sources): Null points western part 6000km A D E C Cospatial south loops East and West Quasi simultaneous

37. Dynamics of CMEs: Detection of weak NT emissions Bastian et al., 2001: « Radio CME » (Maia et al., 2001Plasma front , CME-Driven shock 15 April 2001

38. Moreton waves and flare/CME events Disk event • Moreton wave • Pohjolainen, Maia, Pick, Vilmer et al., 2001

40. Detection of weak emissions (Bastian et al.,2001) CME-Driven shock Plasma front (Maia et al., 2001 CME Radio imaging

41. eruptive scenario (non thermal/thermal emission), observational continuity between eruptive site and coronagraph f.o.v.

42. Feb 28th 2002 • Low energetical release event: ~B4 GOES event, faint type III like bursts. • Dark sigmoïd structure for the initial eruptive filament. • Eruption is triggered by the birth of a small parasitic polarity, a few hours before the D.B. Ref: Marqué, Lantos, Delaboudinière, A&A, 2002, 387,317