The Future of Helioseismology

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The Future of Helioseismology
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NSF Senior Review

• Has recommended that GONG be closed one year
  after successful SDO/HMI commissioning unless
  outside funding can be found.
• According to current schedule, the closure would
  start in late 2009/early 2010 and would take 1 to
  2 years.
• Response
• Expression of concern to NSF from community (Vote
  now!)
• Search for outside funding (starting)
• Planning the future of helioseismology (this talk)

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A Tale of two committees

• In 2002, GONG management proposed that GONG be
  closed one year after the launch of SDO.
• The NSO/AURA Solar Observatories Council rejected
  the proposal, and instead recommended that GONG
  become a permanent NSO flagship facility with
  its own scientific staff. This was accepted by
  the NSO director.
• Now the NSF SR has re-recommended the original
  recommendation.

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Arguments (but who cares?)

• Helioseismology must have at least two facilities
  to confirm discoveries and detect systematic
  errors.
• The upcoming Cycle 24, with widely varying
  predictions for its behavior now that we are
  beginning to have physics-based models, needs to
  be completely studied by helioseismology for
  understanding the generation of magnetic fields.
• Hard to fix SDO when it breaks.
• Helioseismology requires long consistent
  observations SDO/HMI will put a break into the
  space observations and also change spectral
  lines. GONG can operate as a synoptic facility
  forever
• GONG has just brought online continuous
  magnetic field measurements of unparalleled
  precision and cadence.

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The future

• EVEN WITHOUT THE SENIOR REVIEW, GONG instruments
  are aging and will eventually need to be
  replaced.
• SDO will not last forever.
• Is Solar Orbiter a comprehensive helioseismology
  program?
• What does the community want to do next?
• How will it be funded?
• It can take a long time to get the next big thing
  going (typically 10-15 years in the US, Solar
  Orbiter is 30 years from concept to launch)
• Suggest we start to seriously plan for the
  post-GONG and post-SDO era now.
• We are willing to host a planning meeting in
  Tucson

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Hard choices

• Do we need to have two large helioseismology
  observing systems?
• Is global helioseismology still relevant?
• Is a synoptic local helioseismology capability
  necessary?

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Possible next steps

• Add a second (or more?) spectral line to GONG to
  improve studies of magnetic effects, atmospheric
  seismology, energy balance, etc.
• Replace current GONG with a network of 3
  large-aperture, A/O-enabled ground-based
  instruments to access high spatial frequencies.
  Asteroseismology may also benefit
• Do not process GONG data, but collect and archive
  it and analyze as needed. This reduces costs.
• Transition away from pure science to mixture of
  space weather operations and science. This would
  place a new set of constraints on operation of
  the helioseismology facilities.
• Plan the next space mission. Or is it too early?
• Other ideas??

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Planning meeting?

• In Tucson?
• In spring 2007?
• Need broad community participation, especially
  from younger researchers its their future.

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Science Goals

• Probing the zonal and meridional flows in the
  tachocline convection zone to understand the
  operation of the dynamo.
• What is missing from solar/stellar structure
  models? Why is there a large sound speed
  discrepancy at the tachocline?
• G modes?
• Measuring the deep internal magnetic field, esp
  toroidal field in tachocline -- Detecting
  magnetic flux tubes below the surface
• How deep do active regions extend?
• Whats up at the poles?
• How fast does the core rotate?
• Are there internal thermal variations?
• What can helioseismology say about abundances?