V: C5: Coronal Seismology

1
V C5 Coronal Seismology

• Introduction 5 min
• Talks Viggo Hansteen lower atmosphere (10 min)
• Stuart Jefferies chromospheric wave propagation
  (5 min)
• Robertus Erdelyi challenges in theory (15 min)
• Len Culhane theory/spectroscopy/wave detection
  (10 min)
• Jean-Francois Hochedez wave detection (10 min)
• Discussion 20 min
• Next step(s) 5 min

2
II Science questions and tasks

• Primary scientific questions
• The variety of oscillation modes observed with
  SOHO/TRACE in the TR and corona have opened up
  the new field of coronal seismology. By studying
  the properties, excitation, propagation and decay
  of these oscillations/waves, we can reveal
  fundamental physical properties of the TR/corona
  that cannot be accessed as well or at all
  otherwise, such as magnetic field, density,
  temperature, viscosity, sub-resolution
  structuring, ...

3
II Science questions and tasks

• SDO/AIA science tasks
• Task 5A Defining the characteristics of
  transverse, longitudinal and newly discovered
  waves excitation, propagation, decay
• Task 5B Defining the characteristics of global
  coronal waves excitation, propagation, decay
• Task 5C Probing large scale coronal magnetic
  structure and topology
• Task 5D Probing the small scale plasma structure
  and microphysics

4
IV Science investigation

• Hurdles, bottlenecks, uncertainties
• Analytic models need to be improved to include 3D
  effects
• Analytic models need to be augmented by detailed
  2/3D MHD codes
• 3D MHD codes need to include photospheric
  convection, non-LTE chromospheric radiative
  losses and a realistic corona to study the
  coupling to lower atmosphere

5
IV Science investigation

• Hurdles, bottlenecks, uncertainties
• Need automated detection software for
  longitudinal/transverse waves and their triggers
• Automated global wave detection needs to be
  improved
• How can multi-thermal AIA data be used to
  restrain electron densities (crucial for many
  types of coronal seismology)? How reliable are
  density measurements from Solar B EIS?

6
IV Science investigation

• Hurdles, bottlenecks, uncertainties
• NLFFF codes need to be improved (faster, more
  accurate) and coupled to codes which determine
  the magnetic field topology.
• Boundary conditions for field extrapolations need
  to be improved. How do we incorporate
  chromospheric fields and loop morphology into
  extrapolation codes?
• How do we use the coronal field models to
  determine field topology and constrain loop
  lengths? Reliable loop tracing software needs to
  be developed. (Topic I)

7
IV Science investigation

• Hurdles, bottlenecks, uncertainties
• How do we use STEREO to improve our understanding
  of loop geometries/lengths?
• Full disk, high cadence (30 s) H? images needed
  to study Moreton waves simultaneously with
  EIT/AIA waves, also for prominence/filament
  oscillations and propagation from lower
  atmosphere into corona.

8
III Science context

• Expected advances in 2006-2008 prior to SDO
• Automated recognition software to detect global,
  longitudinal and transverse waves,
• Detection of previously undetected wave modes
  (Solar-B), e.g., torsional modes
• Propagation of waves from lower atmosphere into
  corona Solar-B, MHD modeling
• Significant improvement in coronal field
  extrapolations (see topic I), highly useful for
  studies of wave propagation, independent field
  determination, loop lengths, etc
• Incorporation of 3D effects, e.g., magnetic
  curvature, sub-resolution structuring in current
  models
• Improved understanding of the global coronal wave
  phenomenon
• Determination of observable parameters from
  theoretical models

9
III Science context

• Anticipated SDO contributions
• AIA cadence extends parameter space to higher
  frequencies (4-10 x TRACE, up to 0.25 Hz)
• Improved detection rate of all wave types,
  including previously undiscovered wave modes,
  because of large FOV, multi-thermal coverage,
  better S/N
• More accurate coronal seismology through AIA
  multi-thermal coverage better estimates of
  densities and loop lengths (through field
  extrapolation codes), probing of sub-resolution
  structuring

10
III Science context

• Anticipated SDO contributions
• Better understanding of triggering, propagation
  and damping of transverse oscillations through
  combined SDO and Solar-B spectroscopic and vector
  magnetic data
• Improved knowledge of coronal field
  topology/structure through observations of global
  EIT/AIA waves and 3D modeling
• Better understanding of damping and propagation
  of longitudinal waves (e.g., phase mixing)
  through multi-wavelength AIA data, and of
  triggering and damping of longitudinal waves on
  high-temperature (gt5 MK) loops through AIA and
  Solar-B/EIS data

11
III Science context

• Anticipated SDO contributions
• Oscillations in prominences (He II 304 A) and
  coupling to coronal volume
• Look for Alfven waves by tracking transverse
  motions of features in photosphere

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V Implementation general

• What do we need to make progress on the science
  questions in general ?
• TRT Automated wave and loop detection
• TRT Augment analytic models by comparing with
  simplified 2/3D MHD test models
• TRT Bootstrap off topic Is focus on field
  extrapolation/boundary loop recognition
• SRT 3D MHD codes need to include photospheric
  convection, non-LTE chromospheric radiative
  losses and a realistic corona to study the
  coupling to lower atmosphere

13
V Implementation general

• What do we need to make progress on the science
  questions in general ?
• SRT Analytic models need to be expanded to
  include 3D effects, e.g., micro-structuring,
  curvature,
• Working group/workshop on automated wave
  detection software?
• Working group/workshop on wave propagation
  through lower atmospheric boundary 3D MHD codes
• Funding???
• observables, models, codes, resources, people
  see working groups?

14
VI Implementation AIAHMI

• What do we need from and for SDO to make progress
  on our major science?
• Significant progress can be made with the
  standard AIA observing mode
• High frequency domains can be explored by high
  cadence observations for limited fields of view
  and duration in a few select, high S/N passbands
  0.25 Hz is OK, it would be interesting to push
  this as much as possible
• Observing programs/sequences will be optimized
  based on initial observations of, especially,
  triggers of wave phenomena
• Data products database of events with sample
  movies, ideally, automated software, or less
  ideally, high school students full disk, high
  cadence H-alpha movies, density measurements
  (EIS?), coronal field extrapolations

15
VII AIA (HMIEVE) data products

• list data products differentiate critical,
  desirable, useful
• SDO data
• 1600/1700 at 20 s data
• Pipeline for detecting oscillatory power in data?
• Supporting data from other observatories
• XRT, EIS, FPP, ISOON (full disk, high res, high
  cadence H-alpha), radio-data?

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VIII AIA (HMIEVE) data production

• Assessment of required resources/codes/etc
• pipeline software automated detection of
  oscillations
• analysis software/studies wave analysis toolkit
  to ssw
• supporting software/models
• computational requirements (run time estimates,
  system requirements, )
• storage requirements size, duration,
• access web, archive, logs, search methods,

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IX Business plan Resources

• What data and codes must we have to make SDO a
  success (at pipeline, supporting, and research
  levels)? Who will provide the required codes?

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X Business plan Implementation

• Define key milestones, test procedures, and
  target dates,
• Communication define or list meetings, topical
  sessions, etc., where progress can be presented,
  discussed, evaluated,
• is there a need for knowing all oscillatory data
  in TRACE/EIT?