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SECCHI-3D reconstruction software

SECCHI-3D reconstruction software. Wiegelmann, Inhester, Feng, Ruan, Thalmann, Podlipnik. Tools to compute coronal magnetic fields Selfconsistent magnetohydrostatic equilibria Feature recognition Stereoscopy Tomography. Aim: 3D Reconstruction of Solar Corona.

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SECCHI-3D reconstruction software

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  1. SECCHI-3D reconstruction software Wiegelmann, Inhester, Feng, Ruan, Thalmann, Podlipnik • Tools to compute coronal magnetic fields • Selfconsistent magnetohydrostatic equilibria • Feature recognition • Stereoscopy • Tomography 5th SECCHI Consortium Meeting: Wiegelmann et al.: SECCHI-3D reconstruction software

  2. Aim: 3D Reconstruction of Solar Corona • The 2 Viewpoints of STEREO help usfor a 3D-reconstruction. • But: Image data are not sufficient (see talk of Feng) • Essential: Magnetic field information. • Our tools use combined data sets of SECCHIwith photospheric B-field measurements fromvarious instruments (SOHO, HINODE, SOLIS) 5th SECCHI Consortium Meeting: Wiegelmann et al.: SECCHI-3D reconstruction software

  3. Coronal magnetic field codes • Potential, linear and nonlinear force-free extrapolation codes -Cartesian (Active Regions) and-Spherical (Full Sun) geometry • Selfconsistent magnetohydrostatic codes:B-field + Plasma in one MHS-model-Cartesian-Spherical 5th SECCHI Consortium Meeting: Wiegelmann et al.: SECCHI-3D reconstruction software

  4. Better Models More Challenging Computational + Observational 5th SECCHI Consortium Meeting: Wiegelmann et al.: SECCHI-3D reconstruction software

  5. Easy to computeRequire only LOS-Magnetograms 5th SECCHI Consortium Meeting: Wiegelmann et al.: SECCHI-3D reconstruction software

  6. Very Challenging Vector-Magnetograms Pre-processing 5th SECCHI Consortium Meeting: Wiegelmann et al.: SECCHI-3D reconstruction software

  7. 5th SECCHI Consortium Meeting: Wiegelmann et al.: SECCHI-3D reconstruction software

  8. Comparison of observed magnetic loops and extrapolations from photospheric measurements (Wiegelmann et al., A&A 2005) Nonlinear force-free Models are superior. Potential field reconstruction Linear force-free reconstruction Non-linear force-free reconstruction Measured loops in a newly developed AR (Solanki et al., Nature 2003) 5th SECCHI Consortium Meeting: Wiegelmann et al.: SECCHI-3D reconstruction software

  9. Stereoscopy Scaling Laws CME-onset What do coronal B-field models provide? • 3D loop structure • +projections on 2 images • Length + shape of loops • Magnetic field strength • Electric current density • (Free) magnetic energy • Helicity 5th SECCHI Consortium Meeting: Wiegelmann et al.: SECCHI-3D reconstruction software

  10. Compare real + artificial images, Loops + B-lines Modeling,Tomography What does SECCHI provide? • Rigorous Test of B-field models. • Obtain free model parameters. • Test scaling laws. • Get plasma parameters along loops- Temperature- Density- Pressure • Compare selfconsistent MHS-models with coronagraph images (Talk of Ruan) 5th SECCHI Consortium Meeting: Wiegelmann et al.: SECCHI-3D reconstruction software

  11. Single viewpoint: SOHO/EIT, TRACEUse B-Field for feature-recognition(Wiegelmann et al., Sol. Phys. 2005) • Compute the coronal magnetic field. • Project 3D field lines onto an EUV-image. • Emissivity and gradient along projected field lines. • Compare field lines and plasma.How well are they aligned? • Alternative: Extract 1-D loops out of the EUV-images (see talk of Inhester) and compare withprojections of magnetic field lines thereafter. 5th SECCHI Consortium Meeting: Wiegelmann et al.: SECCHI-3D reconstruction software

  12. We use a linear force-free model with MDI-data and have the freedom to choose an appropriate value for the force-free parameter α. EIT-image and projections of magnetic field lines for a potential field (α=0) . (bad agreement) Linear force-free field with α=+0.01 [Mm-1] (bad agreement) 5th SECCHI Consortium Meeting: Wiegelmann et al.: SECCHI-3D reconstruction software

  13. Linear force-free field with α=-0.01 [Mm-1] (better agreement) 3D-magnetic field lines, linear force-free α=-0.01 [Mm-1] 5th SECCHI Consortium Meeting: Wiegelmann et al.: SECCHI-3D reconstruction software

  14. down 3D-Loops guide Data Analysis up Mass flux density inferred from Doppler- shift and intensity from SUMER observations. SUMER Dopplergram in NeVIII ( 77 nm) and a 2-D-projection of some field lines. (Marsch, Wiegelmann, Xia, A&A 2004) 5th SECCHI Consortium Meeting: Wiegelmann et al.: SECCHI-3D reconstruction software

  15. What does the method provide? • Rates quality of magnetic field reconstruction. • Identifies coronal loops. • For a linear force-free model the method computes the optimal force-free parameter α. • The method tells us also how good the assumption “linear force-free” is. (This assumption is good if the optimal value α is the same on all loops.) • Two viewpoints will be more restrictive.Magnetic Stereoscopy, Talk of Feng 5th SECCHI Consortium Meeting: Wiegelmann et al.: SECCHI-3D reconstruction software

  16. Magnetic Models support Tomography, Regularization Magnetic fields and coronal tomography • Use only line of sight density integrals. b) Use only magneticfield data. c) Use both line of sightdensity integrals andmagnetic field as regularization operator. Wiegelmann and Inhester, Sol. Phys, 2003 5th SECCHI Consortium Meeting: Wiegelmann et al.: SECCHI-3D reconstruction software

  17. SECCHI + HINODE + Reconstruction Tools = Corona in 3D Summary • We developed tools for the 3D-reconstructionof the solar corona (global and local). • Combined data-analysis of SECCHI-datawith magnetic field information are morepowerful than 2 STEREO-viewpoints alone. • It is fortunate that we have STEREO and HINODE data available at the same time. 5th SECCHI Consortium Meeting: Wiegelmann et al.: SECCHI-3D reconstruction software

  18. Coronal magnetic field models T. Wiegelmann:Optimization code with weighting function for the reconstruction of coronal magnetic fields. (Sol. Phys., Vol. 219: 87-108, 2004.) T. Wiegelmann, A. Lagg, S.K. Solanki, B. Inhester, J. Woch: Comparing magnetic field extrapolations with measurements of magnetic loops. (A&A, Vol. 433, 701-705, 2005.) T. Wiegelmann, B. Inhester, T.Sakurai: Preprocessing of vector magnetograph datafor a nonlinear force-free magnetic field reconstruction. (Sol. Phys, Vol. 233, 215-232, 2006.) B. Inhester and T. Wiegelmann: Nonlinear force-free magnetic field extrapolations:comparison of the Grad-Rubin and Wheatland-Sturrock-Roumeliotis algorithm. (Sol. Phys., Vol. 235,201-221, 2006) T. Wiegelmann and T. Neukirch: An optimization principle for the computation of MHD equilibria in the solar corona. (A&A, Vol. 457, 1053-1058, 2006.) T. Wiegelmann:Computing nonlinear force-free coronal magnetic fields in spherical geometry. (Solar Physics, in press, 2007) References (Selection) 5th SECCHI Consortium Meeting: Wiegelmann et al.: SECCHI-3D reconstruction software

  19. StereoscopyT. Wiegelmann and T. Neukirch: Including Stereoscopic Information in the Reconstructionof Coronal Magnetic Fields. (Sol. Phys., Vol. 208: 233-251, 2002.) T. Wiegelmann and B.Inhester: Magnetic Stereoscopy. (Solar Physics, Vol. 236, 25-40, 2006.) L.Feng, T. Wiegelmann, B.Inhester, S.K. Solanki, W.Q. Gan, P. Ruan : Magnetic Stereoscopy of Coronal Loops in NOAA 8891. (Sol. Phys., accepted.) B.Inhester: Stereoscopy Basics for the Stereo mission (ISSI publication, submitted .) TomographyT. Wiegelmann and B. Inhester:Magnetic modeling and tomography: First steps towards a consistent reconstruction of the solar corona. (Solar Physics, Vol. 214: 287-312, 2003.) Feature recognition T. Wiegelmann, B. Inhester, A. Lagg, S.K. Solanki:How to use magnetic field information for coronal loop identification?(Sol. Phys., Vol. 228, 67-78, 2005.) 5th SECCHI Consortium Meeting: Wiegelmann et al.: SECCHI-3D reconstruction software

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