1. Braun HMI/AIA Feb 2006 1 using helioseismology to probe magnetic structures (some selected topics) NorthWest Research Associates Colorado Research Associates Division Doug Braun NWRA / CoRA

2. 2Braun HMI/AIA Feb 2006 Barry J. LaBonte

3. 3Braun HMI/AIA Feb 2006 local helioseismology: Hankel analysis Hankel analysis ring diagrams ring diagrams time-distance time-distance helioseismic holography helioseismic holography direct modeling direct modeling Gizon & Birch “Local Helioseismology” 2005 Living Reviews in Solar Physics: livingreviews.org Living Reviews in Solar Physics: livingreviews.org

4. 4Braun HMI/AIA Feb 2006 selected topics: far-side imaging of ARs far-side imaging of ARs emerging ARS emerging ARS flows on AR-scales flows on AR-scales seismic models of sunspots seismic models of sunspots what’s not here excitation of waves by flares excitation of waves by flares magnetic (e.g. tachocline) influences on global modes magnetic (e.g. tachocline) influences on global modes lots of other things lots of other things

5. 5Braun HMI/AIA Feb 2006 I. far-side imaging Lindsey & Braun 2000, Science 287, 1799 Braun & Lindsey 2001, ApJ, 560, L189 http://soi.stanford.edu/data/farside 2-skip + 1,3-skip implementation with MDI: K. Osland and P. Scherrer

6. 6Braun HMI/AIA Feb 2006 far-side imaging with GONG: http://gong.nso.edu/data/farside see poster: González Hernández, et al.

7. 7Braun HMI/AIA Feb 2006 II. (search for) subsurface emergence of magnetic flux Braun, D. 1995, PASP Conf. Series (GONG ‘94), 96, 250 Braun, D. 1995, PASP Conf. Series (GONG ‘94), 96, 250 Chang, H.-K., et al. 1999, ApJ, 526, L53 Chang, H.-K., et al. 1999, ApJ, 526, L53 Kosovichev, A., et al. 2000, Sol Phys, 192, 159 Kosovichev, A., et al. 2000, Sol Phys, 192, 159 Jensen, et al. 2001, ApJ, 553, L193 Jensen, et al. 2001, ApJ, 553, L193 Kosovichev, A. & Duvall, T. 2002, BAAS, 34, 791 Kosovichev, A. & Duvall, T. 2002, BAAS, 34, 791 results range from null, irreproducible (my own), to interesting and worth a second look none probe very deep, in the range where prediction might be practical (?) even without predictive capability, this pursuit is scientifically important

8. 8Braun HMI/AIA Feb 2006 rising flux tube properties thin flux tube calculations (Fan & Gong 2000) time v r (rise speed) two days before emergence: depth z ~ 60 Mm speed v r ~ 150 m/s f ≤ 1let diameter ~ fz (f ≤ 1 !) travel-time perturbation rms of single corr. ≥10 s can get N~100 correlations (maybe); error of mean ≥ 1s direct detection of v r (probably) unlikely, but…? s vava

9. 9Braun HMI/AIA Feb 2006

10. 10Braun HMI/AIA Feb 2006 III. flows on AR scales (SEE H8) ARs as divergent or convergent flows (e.g. Braun et al. 2004) depth variation: shallow inflows and deeper outflows (e.g. Haber et al. 2004) vertical vortiticy, kinetic helicity, other indices (e.g. Komm et al. 2005, SEE POSTER #22)

11. 11Braun HMI/AIA Feb 2006 AR flows with time: AR9906 flows not (simply) related to morphology changes complicated vorticity signatures

12. 12Braun HMI/AIA Feb 2006 sunspots as: Abdelatif, Lites & Thomas 1987, ApJ, 311, 1015 Abdelatif & Thomas 1987, ApJ, 320, 884 Abdelatif, Lites & Thomas 1987, ApJ, 311, 1015 Abdelatif & Thomas 1987, ApJ, 320, 884 Braun, Duvall & LaBonte 1987, ApJ, 319, L27 1988, ApJ, 335, 1015 1988, ApJ, 335, 1015 absorbers refractors

13. 13Braun HMI/AIA Feb 2006 IV. seismic models of sunspots models (forward & inverse) of sound-speed variations models (forward & inverse) of sound-speed variations e.g. Fan, et al. 1995; Kosovichev 1996; Chen et al. 1998; Kosovichev, et al. 2000; Zhao & Kosovichev 2003; Basu, et al. 2004; Couvidat et al. 2004, 2005; Hughes, et al. 2005 e.g. Fan, et al. 1995; Kosovichev 1996; Chen et al. 1998; Kosovichev, et al. 2000; Zhao & Kosovichev 2003; Basu, et al. 2004; Couvidat et al. 2004, 2005; Hughes, et al. 2005 models of flows models of flows e.g. Duvall, et al. 1996; Kosovichev 1996; Gizon et al. 2000; Zhao et al. 2001; Zhao & Kosovichev 2003 e.g. Duvall, et al. 1996; Kosovichev 1996; Gizon et al. 2000; Zhao et al. 2001; Zhao & Kosovichev 2003 models of (other) magnetic effects : complex sound-speed, anisotropy, mode conversion, absorption, upper turning point depressions, etc. models of (other) magnetic effects : complex sound-speed, anisotropy, mode conversion, absorption, upper turning point depressions, etc. e.g. Chen, et al. 1997; Ryutova & Scherrer 1998; Cally, et al. 2004; Crouch, et al. 2005; Lindsey & Braun 2005 e.g. Chen, et al. 1997; Ryutova & Scherrer 1998; Cally, et al. 2004; Crouch, et al. 2005; Lindsey & Braun 2005

14. 14Braun HMI/AIA Feb 2006 sunspot seismology: issues keeping in mind that all models are useful and important… keeping in mind that all models are useful and important… models with similar assumptions (e.g only sound-speed perturbations) often differ substantially models with similar assumptions (e.g only sound-speed perturbations) often differ substantially including realistic magnetic fields in stratified model is very difficult including realistic magnetic fields in stratified model is very difficult no current model is consistent with (i.e. predicts) all observations or known wave interactions in sunspots no current model is consistent with (i.e. predicts) all observations or known wave interactions in sunspots

15. 15Braun HMI/AIA Feb 2006 1 vs 2-skip puzzle: Does 1 vs 2-skip puzzle: Does  - +  + =  2 ? Braun (1997): Braun (1997): No (for  > 150Mm ) No (for  > 150Mm ) Zhao & Kosovichev (2006): Zhao & Kosovichev (2006): Yes (for  =24 – 73 Mm ) Yes (for  =24 – 73 Mm ) Braun (2006): Braun (2006): No (for  =35 – 110 Mm ) No (for  =35 – 110 Mm )  - : incoming travel-time (center-annulus or ingression-control)  2 /2 : (half the) double-skip travel-time (annulus-annulus or egression-ingression)  + : “outgoing travel-time (center-annulus or egression-control) Δ Δ

16. 16Braun HMI/AIA Feb 2006 absorption: mode conversion? slow modes: Spruit & Bogdan Cally & Bogdan (1997) Crouch, et al. (2005) SEE POSTER #17 Hankel analysis : phase shiftsabsorption Holography: : normalized egression power

17. 17Braun HMI/AIA Feb 2006 Schunker, Braun, Cally, & Lindsey 2005 “Local Helioseismology of Inclined Magnetic Fields and the Showerglass Effect,” ApJ 621, L149 Goal: look for evidence of the conversion of vertically oscillating p-modes to elliptical motion in inclined fields in sunspot penumbrae. Observations: MDI (SOHO) - helioseismic IVM (Mees Obs.) – Stokes Method: measure correlation between ingression and direct velocity signal at different projected l.o.s angles (  p ) in plane of magnetic field. AR 9026

18. 18Braun HMI/AIA Feb 2006 evidence for elliptical motion (mode conversion) phasemodulus θpθp varies with field strength/inclination observed throughout 3-5mHz frequency range measured in several spots observed in TD measurements (Zhao & Kosovichev 2006) not predicted for, or observed in, scalar quantities (e.g. intensity) projected line-of-sight angle (from vertical) inner penumbra middle penumbra outer penumbra.

19. 19Braun HMI/AIA Feb 2006challenges: farside: farside: how can we calibrate it? how can we calibrate it? how can we improve it? how can we improve it? emerging ARs: emerging ARs: can we detect direct or indirect effects (e.g. horizontal flows)? can we detect direct or indirect effects (e.g. horizontal flows)? can theories & simulations tell us what to look for? can theories & simulations tell us what to look for? flows: flows: how do we combine surface (Doppler, feature-tracking) and subsurface information? how do we combine surface (Doppler, feature-tracking) and subsurface information? what spatial, temporal scales, products, indices are useful and help solve physical problems? what spatial, temporal scales, products, indices are useful and help solve physical problems? sunspots: sunspots: how do we exploit all of the observations (1,2-skip, frequency variations, lines-of- sight angles, absorption, etc) how do we exploit all of the observations (1,2-skip, frequency variations, lines-of- sight angles, absorption, etc) how do we include explicit magnetic effects in forward (and inverse) models? how do we include explicit magnetic effects in forward (and inverse) models? how can MHD simulations help? how can MHD simulations help?

20. 20Braun HMI/AIA Feb 2006 further information: http://cora.nwra.com/~dbraun NASA (LWS and SR&T programs) NSF (Stellar Astronomy and Astrophysics program) support: