I: C4/C6/M8: Coronal Energy Inputs

1. I: C4/C6/M8: Coronal Energy Inputs Chair(s): Tom Metcalf, Karel Schrijver Status: final (2006/04/04) HMI/AIA science teams meeting; Monterey; Feb. 2006

2. Session(s) outline: • Topical discussions, introduced by speakers & chairs, followed by ‘all’ • Session C4: • Task 1A: determine the 3D configuration of the coronal field • Aad van Ballegooijen on ‘general modeling’ • Task 1B: measure and map the magnetic free energy • Jon Linker on ‘feeding models’, and Brian Welsch on ‘free energy’ • Session C6: • Task 1C: evolution of the field towards unstable configurations • Ed DeLuca on ‘required observational data and derivatives’, Bill Abbett on ‘model of developing instabilities’ • Task 1D: determine the life-cycle of atmospheric field • Alan Title on ‘flux life cycle’, and Alex Pevtsov on ‘…’ • Followed by a discussion. HMI/AIA science teams meeting; Monterey; Feb. 2006

3. II: Science questions and tasks • Primary scientific questions: • Determine the gradual evolution of field geometry/connectivity, and measure the energy in the field during emergence, evolution in the atmosphere, and disappearance from the Sun. • SDO/AIA science tasks: • Task 1A: determine the 3D configuration of the coronal field • Task 1B: measure and map the magnetic free energy • Task 1C: study the evolution of the field towards unstable configurations • Task 1D: determine the life-cycle of atmospheric field HMI/AIA science teams meeting; Monterey; Feb. 2006

4. IIIa: Science context • Expected advances in 2006-2008 prior to SDO: • [discussed in C2]NLFFF modeling (computational speed, effects of boundary & initial conditions, …) • Measurement/mapping of free energy in AR coronae • Use of H and chrom. magnetograms in field modeling/extrapolations • Use of spherical coordinates (embedded in potential environment) , if not global models • Learn to interpret/use ‘relative helicity’ • Field, current (helicity) emergence and coronal field in AR cores (Solar-B FPP & XRT) • High-coronal stereoscopy (STEREO) HMI/AIA science teams meeting; Monterey; Feb. 2006

5. IIIb: Science context • Anticipated SDO contributions: • Reduced ambiguity of AR field geometry (in projection) because of narrower pass bands (lower filling factors) • AR field reconnections studied with improved spatial and thermal resolution because of thermal, spatial, and temporal coverage by AIA • Long-term AR and filament evolution: all targets visible for full disk passage • Interactions between active regions • Flux dispersal into quiet Sun and associated reconnections (low-T corona) • Comparison of full-sphere field models with coronal observations may allow identification of large current systems in the high corona outside active regions, although success of PFSS models suggests these to be limited. • Quiet-Sun filaments (low-T corona) and other field evolution • Complement (rejuvenate?) the STEREO mission by AIA’s “third eye” at mid-angle • Measurement of magnetic helicity (upon emergence as well coronal evolution) HMI/AIA science teams meeting; Monterey; Feb. 2006

6. IVa: Science investigation • Hurdles, bottlenecks, uncertainties, questions: • Can ‘non-potentiality’ be adequately measured, or correlated with CME productivity or flare potential, from a surface field (vector or line-of-sight) only? [e.g., Falconer, Moore, Gary (2003; 2006)] In other words, do we know that we need model field extrapolations, or are surface observations sufficient? How do we establish this? • NLFFF modeling codes are many orders of magnitude too slow: algorithm change or massive parallelization? • Can NLFFF models deal with highly sheared field most relevant to S/W? • High (obs. & model) resolution needed to accommodate gradients in . • Is the 180-degree ambiguity problem adequately solved/solvable? • Limited availability of chromospheric vector-magnetography • How to view/compare the 6 EUV channels and HMI vector magnetograms? • Need automatic, reliable loop tracing algorithm to measure quality of fit of model field to coronal configuration, or … do we need to model an ensemble of loop atmospheres to correlate simulated and observed images without intermediate (subjective?) loop tracing? HMI/AIA science teams meeting; Monterey; Feb. 2006

7. IVb: Science investigation • Hurdles, bottlenecks, uncertainties: • What metric to use to quantify (lack of) correspondence of field model and observed corona? • How to determine usefulness, and how to measure, the quantity called “relative helicity”? • How to measure the various contributions to the Poynting flux? • How can EIS spectroscopy be combined with AIA imaging for 3D geometry studies? • Can reconnection rates be measured if no (unique or verified) field model is available? • H images needed for chromospheric field info. (particularly for filament/prominence and sunspot-field studies) • Are complementary sets of ‘isothermal’ images from DEM inversion more useful than the filter images themselves? If so, how are such isothermal images created, given uncertainties and incompleteness of spectral codes? HMI/AIA science teams meeting; Monterey; Feb. 2006

8. Va: Implementation: general • [What do we need to make progress on the science questions in general?] • [Working groups] • Coordination between GBOs and Space-Based Obs. (Solar-B: FPP and EIS (3D motions), …). Perhaps have “All Resource” [“Great Observatory”] observing programs for pre-defined windows in time, following/negotiating common targets • Vector-velocity determination (to measure relative helicity flux and to help determine Poynting flux) • NLFFF modeling and free-energy measurement group HMI/AIA science teams meeting; Monterey; Feb. 2006

9. Vb: Implementation: general • [What do we need to make progress on the science questions in general?] • [Science stimuli, funding, …] • NLFFF code speed and resolution: high resolution is essential to accommodate strong shear; large number of pixels is needed to model multi-AR interacting fields or large-scale filaments. • 180-degree ambiguity resolution: algorithm speed; options to start from a previous vector-magnetogram. • Funding for (one or more?): • GBO chromospheric vector magnetograms • Solar-B and/or GBO H HMI/AIA science teams meeting; Monterey; Feb. 2006

10. Vc: Implementation: general • [What do we need to make progress on the science questions in general?] • [SR&T/TR&T/…] • [observables, models, codes, resources, people …] • NLFFF model tests on synthetic data • Chromospheric field information ([vector]B, Halpha, …) • Solar-B EIS data for 3D flow determination • … HMI/AIA science teams meeting; Monterey; Feb. 2006

11. VI: Implementation: AIA+HMI • [What do we need from and for SDO to make progress on our major science?] • [observing programs/sequences] • Flare (-response[?]) mode to infer reconnection rates • [data products] • Vector magnetograms [cadence?] • Carefully aligned magnetograms and coronal image sets (for model boundary conditions and for loop tracing) • [turnaround time] • [frequency] • … HMI/AIA science teams meeting; Monterey; Feb. 2006

12. VII: AIA (+HMI+EVE) data products • [list data products; differentiate ‘critical’, ‘desirable’, ‘useful’] • SDO data: • NLFFF model result or tool? Global or local? Frequency? • … • Supporting data from other observatories: • … HMI/AIA science teams meeting; Monterey; Feb. 2006

13. VIIIa: AIA (+HMI+EVE) data production • Assessment of required resources/codes/etc: • [pipeline software] • 3D NLFFF products - or provide ‘supporting software’? • Loop coordinates - or loop-tracing algorithm? • Image alignment for HMI int. and (vector-)B and all AIA channels • [analysis software/studies] • [supporting software/models] • 3D NLFFF model software - or provide data products? • Loop-tracking algorithm - or data product? HMI/AIA science teams meeting; Monterey; Feb. 2006

14. VIIIb: AIA (+HMI+EVE) data production • Assessment of required resources/codes/etc: • [computational requirements (run time estimates, system requirements, …)] • [storage requirements: size, duration, …] • [access: web, archive, logs, search methods, …] HMI/AIA science teams meeting; Monterey; Feb. 2006

15. VIIIc: AIA (+HMI+EVE) data production • Assessment of required resources/codes/etc: • Visualization tools to show: • computed potential fields • compare computed vector fields with observed fields at photospheric and chromospheric levels • display magnetic field, current density, and alpha parameter in any 2D slice through 3D model • trace field lines in 3D model from manually selected "starting" points • find magnetic null points and (quasi-)separatrix surfaces • show field lines and nulls from other (non-SDO) view angles to gain understanding of magnetic geometry • overlay projected field lines and nulls onto AIA or other images for comparison with observed coronal structures • quantify correspondence between field lines and coronal loops • compute magnetic helicity and free energy HMI/AIA science teams meeting; Monterey; Feb. 2006

16. IX: Business plan: Resources • [What data and codes must we have to make SDO a success (at pipeline, supporting, and research levels)? Who will provide the required codes?] • On ‘critical path’: • Funding for field modeling algorithms, testing of these algorithms, and maintenance for general use (perhaps a dedicated processor cluster?) • Funding and infrastructure for complementary data, specifically chromospheric (vector-)magnetograms and H imaging HMI/AIA science teams meeting; Monterey; Feb. 2006

17. X: Business plan: Implementation • [Define key milestones, test procedures, and target dates, …] • … • [Communication: define or list meetings, topical sessions, etc., where progress can be presented, discussed, evaluated, …] • … HMI/AIA science teams meeting; Monterey; Feb. 2006