CME Initiation: The Matrix Reloaded David Alexander, Rice University

Klimchuk Matrix (2000) Model Multi- polar Flux Rope Sheared NL Converg. Flow Recon. Timing Recon. Location Mass Distrib. BreakoutYNRY at/beforeaboveNR Flux RopeNRYYY1Y1 after 1 belowNR NR 2 at/after 2 Tether Cutting NR Y at/beforebelowNR Flux Injection NRY Mass Loading NR cavity and/or prominence What are the key observations that can discriminate among the models?

Pre-event solar atmosphere CME Acceleration Vector B Chromospheric field Photospheric flows Magnetic morphology Emerging/canceling flux Role of reconnection Role of flares Role of filaments Magnetic complexity Helicity evolution Fluxrope formation Triggering phenomena … Accurate H-T and V-T profiles Location of peak acceleration Role of solar wind Relationship to magnetic clouds Interaction with IP medium Flare vs. prominence divide Role of helicity (expulsion?) Changes in magnetic topology Eruption of sheared core field Timing/location of reconnection Production of shocks Wave activity … Modeling Initial + boundary conditions Physical assumptions Driving mechanism ambient conditions Reconnection Heating, Cooling Particle acceleration Shock formation … Ultimate challenge: determine key observational/modeling overlaps and utilize these to provide most appropriate I.C.s and most useful comparisons of model outputs Understanding the CME process observationally

Pre-event solar atmosphere CME Acceleration Observational needs: high cadence vector B high cadence continuum H  filament obs. (inc. Doppler) Modeling needs: include reconnection physics (particles?) inc. observed field configurations and evolution investigate role of emerging/canceling flux incorporate flow fields track helicity …. Observational needs: high cadence low-to-high coronal multi- wavelength observations stereoscopically derived morphology and velocity evolution Modeling needs: specify factors which determine acceleration identify correct boundary conditions how do models distinguish between fast and slow events identify model discriminators in the data

How do we define a realistic challenge and how do we meet it? 3 approaches: - wait until spatial, temporal resolution and source region complexity can be incorporated - Tackle in detail an individual event (e.g May 12) - select 2-3 common phenomena which can be realistically incorporated into the ‘generic’ models e.g. kinking, failed-partial-full eruption, reformation of pre-eruption configuration Non-starter Providing great insight and driving model development Broader application to common processes describing events

Example template of dialog matrix: models The Matrix Reloaded ModelM1 (2.5D)M2 (3D)…… Basic BC Basic Geom. Arcade Fluxropemultipolar Basic concept Driving force shear Loss of equilibrium Reconnection above B field Y (vector) Y H  / He 1083 dynamics EUV/X-ray Y (morphology) M Coronagraph Y Y Solar Wind ? Particles NR Assumptions/ch allenges Sensitivity tests Observational needs Shear profile Definition of Model Observational input/comparison Improving models

Example template of dialog matrix: observations The Matrix Reloaded ObservationMagnetic FieldCoronal (EUV/X-ray) CoronagraphSolar Wind… f-o-v/resolution cadence morphology dynamics Energy release … Pre-eruption Post-eruption Flow maps Topology Assumptions/ch allenges coalignment Control groups … Observational characteristics Relationship to model parameters Improving observations

Dialog template would have additional fields for Definitions and nomenclature Brief discussions Physical quantities: input data/ parameters, output observables, methods for direct comparisons Specify the metric and basis for comparisons Key references Point-counterpoint Emphasis on specific argument and evidence; new observations needed to resolve issues