Energy and Helicity Budget of Four Solar Flares and Associated Magnetic Clouds. Maria D. Kazachenko, Richard C. Canfield, Dana Longcope, Jiong Qiu Montana State University

CMEs Quiet sun structures Active regions Coronal Mass Ejections (CME) ICMEs Non- Cylindrical structures Magnetic clouds (MC) Active regions >1/3

Physical properties: CME vs MC Compare! MC physical properties: axis orientation magnetic flux helicity CME axis orientation magnetic flux helicity magnetic energy radiated energy loss GOES Modeled

Fast magnetic reconnection during flare CME: flux rope formation To model CME flux rope properties we need to understand When are the flux ropes formed? Before flare Pre-existing Emerge twisted Formed by slow pre-flare magnetic reconnection Low (1994), Fan & Gibson (2004), Leka et al. (1996), Abbett & Fisher (2003), van Ballegooijen & Martens (1989), Mackay and van Ballegooijen (2001), Forbes & Priest (1995), Antiochos et al. (1999), Lynch et al. (2004) Moore & LaBonte 1980, Mikic & Linker 1994, Demoulin et al. 1996, 2002; Magara et al. 1997; Antiochos et al. 1999; Choe & Cheng 2000; Nindos & Zhange (2002), Qiu et al. (2007), Longcope (2007). During flare Formed in-situ

Hypothesis: MCs originate from the ejection of locally in-situ formed flux ropes. Tools: Minimum Current Corona Model; MC, ribbon observations for four eruptive solar flares with MCs. Analysis: Compare observed reconnection flux, energy, helicity with MCC model results. Results Comply with the scenario of in situ formed FR Work Outline

CSHKP. Minimum Current Corona Model 2D 3D Closed field lines X-point Current sheet Ribbons Opened field lines Plasmoid (CME) Separatrix Flux rope MC) Reconnection flux,  rec Poloidal flux,  P Carmichael (1964), Sturrock (1968), Hirayama (1974), Kopp and Pneuman (1976), Gosling (1990, 1995) Minimum Current Corona Model, Longcope (1996)

Magnetic point charge motions before May flare Magnetic field evolution in 40 hr. Magnetic field evolution Set of magnetograms Set of magnetic regions Set of magnetic point charges LCT T0 T0+40 hr November & Simon (1988)

Magnetic field topology Red: multiple domains Green: separator

MCC: Magnetic stress buildup Stress builds up Release No reconnection Constant Domain fluxes Non-potentiality builds To preserve topology currents flow along separators Reconnection relaxes field to potential. Reconnection relaxes field to potential. T0 T flare

MCC: Magnetic stress buildup Stress builds up No reconnection Release T0 T flare T0 T flare

MC/flare properties: MCC Charge motion. No emergence. Currents build along separators Reconnection flux,  r,MCC Flare magnetic energy, E MCC Flare Helicity, H MCC Topology does not change Field becomes potential Topology changes Field becomes potential MCC Topology changes MDI, TRACE data + Longcope, Cowley (1996), Longcope & Magara (2004)

MC/flare properties: MCC Wind/ACE MC in situ data Grad-Shafranov and Lundquist fit MC poloidal flux  P, Helicity H obs GOES 1-8 A Mewe loss function Radiated energy loss, E obs + TRACE 1600 A Reconnection flux,  r,obs Ribbon motion + + L=1 AU Reconnection flux,  r,MCC Magnetic energy, E MCC Helicity, H MCC MCC MDI, TRACE 1600 A + MC/flare properties: Observations

Flares studied Selection criteria observations of both flare and MC two successive flares (>M) in one AR both close to the disk center no significant flux emergence/cancellation

 r ≈ [0.15, 0.40] *  AR  r,MCC ≤  r,obs MCC captures the lower limit of the reconnection flux.  p ≤  r,obs Supports CSHKP model (Qiu 2007). Uncertainties: TRACE ribbon edge identification, MC fitting (MC length, boundaries) Results: Magnetic flux

Results: Energy E MCC ≥ E obs MCC implies shearing/rotation provide enough energy to account for radiated energy loss. Uncertainties: GOES thermal radiated energy loss – lower limit on the energy (neglects thermal conduction and non-thermal energy). MCC model estimates minimum energy. Longcope, DesJardins et al.(2010), Raftery et al. (2009), Longcope (2001)

Results: Magnetic Helicity H MCC ≈ H obs No preexisting twist required in these events H MCC, H obs < H AR Uncertainties: MC fitting (model-dependent, length, boundaries), fraction of H which goes into the flux rope (assume ½) Dasso (2003), (2006), Gibson (2008), Mackay (2006)

Conclusions Main purpose of the study: Understand the FR formation and its relationship with the MC Tool, Data MCC model + observations for four eruptive solar flares with MCs Results: In these four events, the MCC model is able to account for the observed reconnection flux, FR helicity and flare energy. It suggests that: FRs are formed in situ within the AR, Flux emergence is relatively unimportant, No preexisting twist is required. Uncertainties: MC length, flux rope escape, total flare energy estimate. Kazachenko et al. 2009, 2010

Acknowledgements Richard Canfield, Dana Longcope, Jiong Qiu, Angela DesJardins, Richard Nightingale, Qiang Hu, NASA.

Questions?

Physical properties: MCC vs observations

Flux rope formed in situ. CSHKP. 2D3D Closed field lines X-point Current sheet Ribbons Opened field lines Plasmoid (CME) Separatrix Flux rope MC) Reconnection flux,  rec Poloidal flux,  P Carmichael (1964), Sturrock (1968), Hirayama (1974), Kopp and Pneuman (1976), Gosling (1990, 1995) Minimum Current Corona Model, Longcope (1996)