Discussion Summary: Group B

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Discussion Summary Group B Solar Active
Regions And Their Production of Flares and
Coronal Mass Ejections

• Discussion Leaders
• George Fisher
• Hugh Hudson

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Our Discussion led to 2 classes of potential
solar hazard prediction tools

• Existing techniques that have obvious usefulness,
  but need further development and testing
• Strategic tools that will offer much better
  solar-weather forecasting, but need a sustained
  effort over a long time before the results will
  be achieved

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Promising solar forecast tools that exist now

• Empirical Magnetogram based predictors for CMEs
  and Flares in active regions

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• Helioseismic forecasts of active regions
• before they rotate around the limb

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... before they emerge, and before the
occurrence of large flares
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Other existing techniques that appear very
promising and/or easily implemented and tested

• Force-free magnetogram measures of free magnetic
  energy
• Measuring the flux of magnetic free energy
  through the photosphere
• Coronal morphology changes 6-24 hours prior to
  eruption, e.g. coronal density enhancements

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Strategic research that will lead to better
prediction of CMEs I

• Force-free (chromosphere or higher) vector
  magnetograms
• Techniques for assimilating datasets relevant to
  the global coronal magnetic field, radio and
  X-ray/EUV imaging spectroscopy, and coronal
  seismology.
• Detailed observational determination of the
  magnetic topology in filament channels to
  determine the CME eruption mechanism

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Strategic research that will lead to better
prediction of CMEs II

• Observational investigations of the sequence of
  events in filament, CME, and flare dynamics at
  flare onset and early development.
• Self-consistent MHD models of coupled
  photospheric, chromospheric, and coronal parts of
  the solar atmosphere to pursue a vigorous
  investigation of CME initiation physics and how
  to drive such models with real observational
  data.
• Determine how flares (e.g., magnetic
  reconnection) can accelerate particles able to
  fill a large open-field domain

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Resources a Sentinels Component

• A Sentinels program is essential for improved
  forecasting of dangerous solar activity on time
  scales of days to weeks
• The most important Sentinels observation would be
  line-of-sight magnetography

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Other needed resources

• Measurements of coronal magnetic field strength
  on the solar disk.
• spectroscopic coronagraph to measure shocks in
  low corona
• space-based force-free full-disk vector
  magnetograph