I: C1/M8 /C10 Transients: Drivers & Destabilization

1. I: C1/M8/C10 Transients: Drivers & Destabilization Chair(s): Golub & Nitta Status: [draft/review/final]

2. Schedule • 17 November 2005: draft sheets I, II to teams, requesting input for sheets III and IV • 24 November 2005: completed sheets I-IV for review to teams, requesting input for sheets V-VI • 8 December 2005: team input received for sheets V-VI • 19 December 2005: draft of sheets VII-VIII to teams • 9 January 2006: team comments received for sheets VII-VIII • 6 February 2006: draft ‘Science plans’ on meeting website, with sheets IX-X filled out by team leads (or teams after telecons) • 13-17 February 2006: discussions during science team meeting discuss and complete pages IX-X. • 17 February: completed ‘Science plans’ on line.

3. II: Science questions and tasks (1) • Primary scientific question: • What types of magnetic field evolution lead to instabilities and transients? • What is the role of helicity injection and transfer? • How does emerging flux interact with pre-existing B? • How is the stored magnetic released? • Is there a role for flux ropes? • Where and how does reconnection occur?

4. II: Science questions and tasks (2) • SDO/AIA science tasks: • Task [1]: Unstable field configurations and initiation of transients • Find pre-eruption signatures of, e.g., tether-cutting or breakout reconnection. • Is braiding or sigmoid formation an eruption indicator? • How do we best observe and use coronal dimming? • Task [2]: Evolution of transients • Find signatures of inflow and outflow, cusps, patchiness of reconnection. • Determine how much flux participates in reconnection episodes. D. McKenzie Overview Presentation • Task [3]: Early evolution of CMEs (Session C10) • Task [4]: Particle acceleration (Session C10)

5. III: Science context • Solar-B is likely to provide improved knowledge of locations of reconnection sites, inflows and outflows and local magnetic structure (modeled). • Combination of XRT, EIS and B-extrapolations. • STEREO should provide improved knowledge of global configuration, in both plasma and field, and relation to properties of eruption. • e.g., two magnetic configurations (normal and inverse) vs. CME speed. • Flux rope – ab initio vs. formed during event

6. III: Science context (cont.) • SDO will provide unique global coverage of: • Pre-eruption coronal topology • Magnetic field structure • Event initiation and early evolution Y. Su Presentation on shear change • How SDO data can be used: • From B maps determine null points, separatrices or QSLs. • EUV channels provide imaging temperature (DEM) maps of corona and its evolution. • Locate and compare first brightenings and energy release sites vs. global conditions (multi-polarity, helicity, etc,).

7. III: Science context (cont.) • How to use SDO: • Evolution of the full magnetic configuration. • Determination of coronal B and comparison with EUV observations. • Observe T-slices of coronal structure, to follow all of the plasmas as f(t). • Need to know the large-scale field • Is “breakout” configuration a necessary condition? • Systematic observations of pre-CME phase: • Flux tube present or not? Role of kink instability? Fludra/Harrison Presentation on CME Detection

8. IV: Science investigation • Hurdles, bottlenecks, uncertainties: • Parameters of flare trigger are unknown: location, size, temperature, density. • Consequences of energy release and particle acceleration are visible (flare ribbons, chromospheric evaporation, heated plasma) but energy release site is not directly observed. • Large gap remains between B-extrapolations and observed coronal structure; not clear how to make progress.

9. IV: Science investigation (cont.) • Hurdles, bottlenecks, uncertainties (cont.): • What coronagraph observations will be available? SOHO? STEREO? Other? • Need to study tradeoffs for AIA: Number of channels vs. image cadence vs. complexity of planning.