Solar MURI Vector Magnetogram Mini-Workshop

1
Solar MURI Vector Magnetogram Mini-Workshop

• Using Vector Magnetograms in Theoretical Models
• Plan of Action

2
Overview of the plan

• Phase I
• Analyze available data for 1998 May 1 event
• Construct coronal magnetic equilibria
• Develop velocity inversion methods
• Test velocity inversion methods
• Study a second (simpler) event
• Phase II
• Carry out MHD simulations
• Couple coronal and IP codes
• Phase III
• Validation of modelling using available solar and
  IP data

3
Analyze available data for 1998 May 1 event

1. Generate a sequence of IVM magnetograms for the
   1998 May 1 2340 UT halo CME event (AR 8210),
   time cadence 15 min (too slow ?), before,
   during, and after eruption. (Regnier)
2. Estimate the magnetic field uncertainties.(Metcalf
   , Leka)
3. Determine line of sight and transverse
   velocities. (Welsch, Metcalf)
4. Analyze the global solar (Li, Liu) and IP (Li,
   Luhmann) context (spatial, temporal) of this
   event, time scale several days, including
   previous and following events.
5. Make an instrument vs time array on WWW (Li)

4
Construct coronal magnetic equilibria

1. Build force-free magnetic field models for each
   magnetogram, combined with a potential
   extrapolation of MDI data. (Regnier)
2. Build magnetostatic models from the same
   magnetograms (Heinemann).
3. Compare force-free magnetic field models to
   available coronal imaging data (Canfield,
   Metcalf)
4. Compare connectivity of force-free models to that
   of point charge models (Regnier, Longcope, Leka)

5
Develop velocity inversion methods

1. Use vertical component of induction equation to
   derive velocity fields (Longcope, Fisher, Welsch)
2. Constrain the solutions by minimizing total
   kinetic energy (ditto)

6
Test velocity inversion methods

1. Generate fake magnetogram sequences from the MHD
   simulations (Abbett, Fisher)
2. Use velocity inversion techniques to infer
   velocities from these sequences (ditto Welsch)
3. Compare photospheric boundary velocities from the
   simulation to those inferred from the inversion
   (same as 2)
4. Explore implications of magnetogram uncertainties
   through Monte Carlo methods (same as 2).
5. Compare velocities from the inversion to IVM
   observations (Welsch, Metcalf, Abbett, Fisher)

7
Study a second (simpler) event (Liu)

1. Identify a simpler solar and IP event for
   analysis (1997 May 12 halo CME in AR8038 ?).
2. Produce a vector magnetogram (Solar Flare
   Telescope / Mitaka ?) sequence for this event.
3. Carry out an analysis parallel to that of the
   1998 May 1 event (no velocity observations
   available or use LCT methods for v_t, MDI for
   v_l?) (Liu Welsch)

8
Carry out MHD simulations

• Do Zeus AMR simulations using real magnetic field
  data near time of CME using synoptic magnetic
  field solutions as boundary condition. (Berkeley
  mafia)
• Couple coronal and interplanetary codes
• (Abbett, Ledvina, Odstrcil)