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 region

s

Coronal Mass Ejections (CME)

ICMEs

Non-Cylindri

cal structur

es

Magnetic

clouds

(MC)

Magnetic

clouds

(MC)

Active region

s

>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

GOESModeled

• 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 reconnectionLow (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 flareFormed 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

Model2D 3D

Closed field lines

X-pointCurrent 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 13 2005 flare

Magnetic field evolution in 40 hr.

Magnetic field evolution

Set of magnetogram

s

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

1 2

Stress builds up

ReleaseRelease

No reconnection Constant Domain fluxes Non-potentiality buildsTo preserve topology currents flow along separators

Reconnection relaxes field to potential.

Reconnection relaxes field to potential.

T0 Tflare

MCC: Magnetic stress buildup

1 2

Stress builds upNo reconnection

ReleaseRelease

T0 Tflare

T0 Tflare

MC/flare properties: MCC

Charge motion. No emergence.

Currents build along separators

Reconnection flux, r,MCC

Flare magnetic energy, EMCC

Flare Helicity, HMCC

Topology does not change

1

Field becomes potential

2

Topology

changes

Field becomes potential

MCC

Topology

changes

MDI, TRACEdata

+

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 Hobs

GOES 1-8 A Mewe loss function Radiated energy loss, Eobs+

TRACE 1600 A

Reconnection flux, r,obs

Ribbon motion

+

+

L=1 AU

Reconnection flux, r,MCC

Magnetic energy, EMCC

Helicity, HMCC

MCCMDI, 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

• EMCC ≥ Eobs

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

• HMCC ≈ Hobs

No preexisting twist required in these events

• HMCC, Hobs < HAR

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)

ConclusionsMain purpose of the study:

Understand the FR formation and its relationship with the MC

Tool, DataMCC 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