Possible New Avenues for Ambiguity Resolution

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Possible New Avenues for Ambiguity Resolution

• K. S. Balasubramaniam, NSO

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Surface methods

• Surface modeling of the measured LOS component of
  the field
• Extrapolation/modeling of the measured surface
  magnetic field
• Potential field, force-free field, sheared lines,
  vertical current, energy minimization,
  neighborhood approximation etc.
• Trust but verify Uniqueness??

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Depth-dependent Method

• Radiative transfer inversion solutions that seek
  height dependence of the solution
• Fit the observed spectral line via a non-linear
  least square unconstrained optimization.
• PCA, SVM
• Assumptions of a depth dependent continuity, no
  room for vertical shear.
• No knowledge of the behavior of neighborhood
  surface elements.
• Trust, but verify Uniqueness of the solution.

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Solutions

• Observational
• Flux-balance and minimizing excess flux in the
  choice of active-region coverage

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Solutions

• Observational
• Flux-balance and minimizing excess flux in the
  choice of active-region coverage
• Minimize Flux Imbalance
• Either from extract of the full-disk vector data
  e.g. SOLIS or from full-disk LOS data from MDI,
  SOLIS or elsewhere temporally close data.
• Choice of the active-region scanning area in
  area-limited instruments to cover flux balance
• Splice data between instruments to match
  flux-balance.
• Activity boundary identification ? Plage,
  Filament?, Sunspot Groups??

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Future Inversion Pathways

• Present inversion of spectral line profiles with
  radiation transfer (RT) solutions is blind to
  neighborhood knowledge in terms of physics.
• Simultaneously fit measured fields and depth
  dependent information via RT and field variation
• ¼ Curl (B??) ? ?p ?g
• Near-simultaneous multi-line vector polarimetry
• Automated multi-line resolution
• Modification of AR scans in present instruments
  for minimizing FOV flux balance

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Future Inversion Pathways

• The heights of formation of the line at t 1
  layer, is not the same geometric height. Let
  vertical gradients from multi-line measurements
  fit to the extrapolation model, to include
  vertical shear?
• Is new emergent flux, and resultant transverse
  field considered a part of the old flux for
  purposes of extrapolation resolution?
• Stereo measurements
• Fill factor
• Future vector instruments space and ground

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• Is new flux due