Skip to main content
SpringerLink
Log in

Surface-Focused Seismic Holography of Sunspots: I. Observations

  • HELIOSEISMOLOGY, ASTEROSEISMOLOGY, AND MHD CONNECTIONS
  • Published:
Solar Physics Aims and scope Submit manuscript

Abstract

We present a comprehensive set of observations of the interaction of p-mode oscillations with sunspots using surface-focused seismic holography. Maps of travel-time shifts, relative to quiet-Sun travel times, are shown for incoming and outgoing p modes as well as their mean and difference. We compare results using phase-speed filters with results obtained with filters that isolate single p-mode ridges, and we further divide the data into multiple temporal frequency bandpasses. The f mode is removed from the data. The variations of the resulting travel-time shifts with magnetic-field strength and with the filter parameters are explored. We find that spatial averages of these shifts within sunspot umbrae, penumbrae, and surrounding plage often show strong frequency variations at fixed phase speed. In addition, we find that positive values of the mean and difference travel-time shifts appear exclusively in waves observed with phase-speed filters that are dominated by power in the low-frequency wing of the p 1 ridge. We assess the ratio of incoming to outgoing p-mode power using the ridge filters and compare surface-focused holography measurements with the results of earlier published p-mode scattering measurements using Fourier – Hankel decomposition.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • Barnes, G., Cally, P.S.: 2001, Frequency dependent ray paths in local helioseismology. Publ. Astron. Soc. Aust. 18, 243 – 251.

    Article  ADS  Google Scholar 

  • Basu, S., Antia, H.M., Bogart, R.S.: 2004, Ring-diagram analysis of the structure of solar active regions. Astrophys. J. 610, 1157 – 1168.

    Article  ADS  Google Scholar 

  • Benson, D., Stein, R., Nordlund, Å.: 2006, Supergranulation scale convection simulations. In: Uitenbroek, H., Leibacher, J., Stein, R.F. (eds.) Solar MHD Theory and Observations: A High Spatial Resolution Perspective, Astron. Soc. Pac. Conf. Ser. 354, Astron. Soc. Pac., San Francisco, 92 – 96.

    Google Scholar 

  • Birch, A.C., Braun, D.C., Hanasoge, S.M.: 2008, Surface-focused seismic holography of sunspots: II. Expectations from numerical simulations using sound-speed perturbations. Solar Phys., submitted (Paper 2).

  • Bogdan, T.J.: 2000, Sunspot oscillations: A review. Solar Phys. 192, 373 – 394.

    Article  ADS  Google Scholar 

  • Bogdan, T.J., Braun, D.C.: 1995, Active region seismology. In: Hoeksema, J.T., Domingo, V., Fleck, B., Battrick, B. (eds.) Helioseismology, SP-376, ESA, Noordwijk, 31 – 45.

    Google Scholar 

  • Bogdan, T.J., Brown, T.M., Lites, B.W., Thomas, J.H.: 1993, The absorption of p modes by sunspots – variations with degree and order. Astrophys. J. 406, 723 – 734.

    Article  ADS  Google Scholar 

  • Braun, D.C.: 1995, Scattering of p modes by sunspots. I. Observations. Astrophys. J. 451, 859 – 876.

    Article  ADS  Google Scholar 

  • Braun, D.C.: 1997, Time – distance sunspot seismology with GONG data. Astrophys. J. 487, 447 – 456.

    Article  ADS  Google Scholar 

  • Braun, D.C., Birch, A.C.: 2006, Observed frequency variations of solar p-mode travel times as evidence for surface effects in sunspot seismology. Astrophys. J. 647, L187 – L190.

    Article  ADS  Google Scholar 

  • Braun, D.C., Lindsey, C.: 2000, Phase-sensitive holography of solar activity. Solar Phys. 192, 307 – 319.

    Article  ADS  Google Scholar 

  • Braun, D.C., Birch, A.C., Lindsey, C.: 2004, Local helioseismology of near-surface flows. In: Danesy, D. (ed.) SOHO 14 Helio- and Asteroseismology: Towards a Golden Future, SP-559, ESA, Noordwijk, 337 – 340.

    Google Scholar 

  • Braun, D.C., Duvall, T.L. Jr., LaBonte, B.J.: 1987, Acoustic absorption by sunspots. Astrophys. J. 319, L27 – L31.

    Article  ADS  Google Scholar 

  • Braun, D.C., Duvall, T.L. Jr., LaBonte, B.J.: 1988, The absorption of high-degree p-mode oscillations in and around sunspots. Astrophys. J. 335, 1015 – 1025.

    Article  ADS  Google Scholar 

  • Braun, D.C., Duvall, T.L. Jr., Labonte, B.J., Jefferies, S.M., Harvey, J.W., Pomerantz, M.A.: 1992, Scattering of p modes by a sunspot. Astrophys. J. 391, L113 – L116.

    Article  ADS  Google Scholar 

  • Cally, P.S., Crouch, A.D., Braun, D.C.: 2003, Probing sunspot magnetic fields with p-mode absorption and phase shift data. Mon. Not. Roy. Astron. Soc. 346, 381 – 389.

    Article  ADS  Google Scholar 

  • Cameron, R., Gizon, L., Daiffallah, K.: 2007, SLiM: A code for the simulation of wave propagation through an inhomogeneous, magnetised solar atmosphere. Astron. Nachr. 328, 313 – 318.

    Article  MATH  ADS  Google Scholar 

  • Cameron, R., Gizon, L., Duvall, T. Jr.: 2008, Helioseismology of sunspots: Confronting observations with three-dimensional MHD simulations of wave propagation. Solar Phys., submitted.

  • Chou, D.Y.: 2000, Acoustic imaging of solar active regions. Solar Phys. 192, 241 – 259.

    Article  ADS  Google Scholar 

  • Christensen-Dalsgaard, J., Gough, D.O., Perez Hernandez, F.: 1988, Stellar disharmony. Mon. Not. Roy. Astron. Soc. 235, 875 – 880.

    ADS  Google Scholar 

  • Couvidat, S., Rajaguru, S.P.: 2007, Contamination by surface effects of time – distance helioseismic inversions for sound speed beneath sunspots. Astrophys. J. 661, 558 – 567.

    Article  ADS  Google Scholar 

  • Couvidat, S., Birch, A.C., Kosovichev, A.G.: 2006, Three-dimensional inversion of sound speed below a sunspot in the Born approximation. Astrophys. J. 640, 516 – 524.

    Article  ADS  Google Scholar 

  • Couvidat, S., Birch, A.C., Kosovichev, A.G., Zhao, J.: 2004, Three-dimensional inversion of time – distance helioseismology data: Ray-path and Fresnel-zone approximations. Astrophys. J. 607, 554 – 563.

    Article  ADS  Google Scholar 

  • Crouch, A.D., Cally, P.S., Charbonneau, P., Braun, D.C., Desjardins, M.: 2005, Genetic magnetohelioseismology with Hankel analysis data. Mon. Not. Roy. Astron. Soc. 363, 1188 – 1204.

    Article  ADS  Google Scholar 

  • Duvall, T.L. Jr., Gizon, L.: 2000, Time – distance helioseismology with f modes as a method for measurement of near-surface flows. Solar Phys. 192, 177 – 191.

    Article  ADS  Google Scholar 

  • Duvall, T.L. Jr., D’Silva, S., Jefferies, S.M., Harvey, J.W., Schou, J.: 1996, Downflows under sunspots detected by helioseismic tomography. Nature 379, 235 – 237.

    Article  ADS  Google Scholar 

  • Fan, Y., Braun, D.C., Chou, D.Y.: 1995, Scattering of p modes by sunspots. II. Calculations of phase shifts from a phenomenological model. Astrophys. J. 451, 877 – 888.

    Article  ADS  Google Scholar 

  • Giles, P.M.: 2000, Time – distance measurements of large-scale flows in the solar convection zone. Ph.D. thesis, Stanford University.

  • Gizon, L., Birch, A.C.: 2002, Time – distance helioseismology: The forward problem for random distributed sources. Astrophys. J. 571, 966 – 986.

    Article  ADS  Google Scholar 

  • Gizon, L., Birch, A.C.: 2005, Local helioseismology. Liv. Rev. Solar Phys. 2. http://www.livingreviews.org/lrsp-2005-6 (cited on 14 February 2008).

  • Gizon, L., Duvall, T.L. Jr., Larsen, R.M.: 2000, Seismic tomography of the near solar surface. J. Astrophys. Astron. 21, 339 – 342.

    ADS  Google Scholar 

  • Gordovskyy, M., Jain, R.: 2007, Scattering of p modes by a thin magnetic flux tube. Astrophys. J. 661, 586 – 592.

    Article  ADS  Google Scholar 

  • Hanasoge, S.M., Duvall, T.L. Jr.: 2007, The solar acoustic simulator: Applications and results. Astron. Nachr. 328, 319 – 322.

    Article  MATH  ADS  Google Scholar 

  • Hanasoge, S.M., Duvall, T.L. Jr., Couvidat, S.: 2007, Validation of helioseismology through forward modeling: Realization noise subtraction and kernels. Astrophys. J. 664, 1234 – 1243.

    Article  ADS  Google Scholar 

  • Hanasoge, S.M., Couvidat, S., Rajaguru, S.P., Birch, A.C.: 2007, Impact of locally suppressed wave sources on helioseismic travel times. Astrophys. J., submitted. http://arxiv.org/abs/0707.1369v3.

  • Hughes, S.J., Rajaguru, S.P., Thompson, M.J.: 2005, Comparison of GONG and MDI: Sound-speed anomalies beneath two active regions. Astrophys. J. 627, 1040 – 1048.

    Article  ADS  Google Scholar 

  • Jackiewicz, J., Gizon, L., Birch, A.C.: 2008, High-resolution mapping of flows in the solar interior: Fully consistent OLA inversion of helioseismic travel times. Solar Phys., submitted.

  • Jackiewicz, J., Gizon, L., Birch, A.C., Duvall, T.L. Jr.: 2007a, Time-distance helioseismology: Sensitivity of f-mode travel times to flows. Astrophys. J. 671, 1051 – 1064.

    Article  ADS  Google Scholar 

  • Jackiewicz, J., Gizon, L., Birch, A.C., Thompson, M.J.: 2007b, A procedure for the inversion of f-mode travel times for solar flows. Astron. Nach. 328, 234 – 239.

    Article  ADS  Google Scholar 

  • Jensen, J.M., Duvall, T.L. Jr., Jacobsen, B.H.: 2003, Noise propagation in inversion of helioseismic time – distance data. In: Sawaya-Lacoste, H. (ed.) GONG+ 2002. Local and Global Helioseismology: The Present and Future, SP-517, ESA, Noordwijk, 315 – 318.

    Google Scholar 

  • Jensen, J.M., Duvall, T.L. Jr., Jacobsen, B.H., Christensen-Dalsgaard, J.: 2001, Imaging an emerging active region with helioseismic tomography. Astrophys. J. 553, L193 – L196.

    Article  ADS  Google Scholar 

  • Khomenko, E., Collados, M.: 2006, Numerical modeling of magnetohydrodynamic wave propagation and refraction in sunspots. Astrophys. J. 653, 739 – 755.

    Article  ADS  Google Scholar 

  • Korzennik, S.G.: 2006, The cookie cutter test for time – distance tomography of active regions. In: Proceedings of SOHO 18/GONG 2006/HELAS I, Beyond the Spherical Sun, SP-624, ESA, Noordwijk, 60.

    Google Scholar 

  • Kosovichev, A.G.: 1996, Tomographic imaging of the Sun’s interior. Astrophys. J. 461, L55 – L57.

    Article  ADS  Google Scholar 

  • Kosovichev, A.G., Duvall, T.L. Jr.: 1997, Acoustic tomography of solar convective flows and structures. In: Pijpers, F.P., Christensen-Dalsgaard, J., Rosenthal, C.S. (eds.) SCORe’96: Solar Convection and Oscillations and their Relationship, Astrophys. Spa. Science 225, 241 – 260.

  • Kosovichev, A.G., Duvall, T.L. Jr., Scherrer, P.H.: 2000, Time – distance inversion methods and results. Solar Phys. 192, 159 – 176.

    Article  ADS  Google Scholar 

  • Lindsey, C., Braun, D.C.: 1997, Helioseismic holography. Astrophys. J. 485, 895 – 903.

    Article  ADS  Google Scholar 

  • Lindsey, C., Braun, D.C.: 1999, Chromatic holography of the sunspot acoustic environment. Astrophys. J. 510, 494 – 504.

    Article  ADS  Google Scholar 

  • Lindsey, C., Braun, D.C.: 2000, Basic principles of solar acoustic holography. Solar Phys. 192, 261 – 284.

    Article  ADS  Google Scholar 

  • Lindsey, C., Braun, D.C.: 2004a, Principles of seismic holography for diagnostics of the shallow subphotosphere. Astrophys. J. Suppl. 155, 209 – 225.

    Article  ADS  Google Scholar 

  • Lindsey, C., Braun, D.C.: 2004b, The penumbral acoustic anomaly. In: Danesy, D. (ed.) SOHO 14 Helio- and Asteroseismology: Towards a Golden Future, SP-559, ESA, Noordwijk, 552.

    Google Scholar 

  • Lindsey, C., Braun, D.C.: 2005a, The acoustic showerglass. I. Seismic diagnostics of photospheric magnetic fields. Astrophys. J. 620, 1107 – 1117.

    Article  ADS  Google Scholar 

  • Lindsey, C., Braun, D.C.: 2005b, The acoustic showerglass. II. Imaging active region subphotospheres. Astrophys. J. 620, 1118 – 1131.

    Article  ADS  Google Scholar 

  • Lindsey, C., Schunker, H., Cally, P.S.: 2007, Magnetoseismic signatures and flow diagnostics beneath magnetic regions. Astron. Nachr. 328, 298 – 304.

    Article  ADS  Google Scholar 

  • Lites, B.W.: 1992, Sunspot oscillations – observations and implications. In: Thomas, J.H., Weiss, N.O. (eds.) NATO ASIC Proc. 375: Sunspots. Theory and Observations, Kluwer, Dordrecht, 261 – 302.

    Google Scholar 

  • Mansour, N.N., Kosovichev, A.G., Georgobiani, D., Wray, A., Miesch, M.: 2004, Turbulence convection and oscillations in the Sun. In: Danesy, D. (ed.) SOHO 14 Helio- and Asteroseismology: Towards a Golden Future, SP-559, ESA, Noordwijk, 164 – 171.

    Google Scholar 

  • Parchevsky, K.V., Zhao, J., Kosovichev, A.G.: 2008, Influence of non-uniform distribution of acoustic wavefield strength on time – distance helioseismology measurements. Astrophys. J., submitted.

  • Rajaguru, S.P., Birch, A.C., Duvall, T.L. Jr., Thompson, M.J., Zhao, J.: 2006, Sensitivity of time – distance helioseismic measurements to spatial variation of oscillation amplitudes. I. Observations and a numerical model. Astrophys. J. 646, 543 – 552.

    Article  ADS  Google Scholar 

  • Rajaguru, S.P., Sankarasubramanian, K., Wachter, R., Scherrer, P.H.: 2007, Radiative transfer effects on Doppler measurements as sources of surface effects in sunspot seismology. Astrophys. J. 654, L175 – L178.

    Article  ADS  Google Scholar 

  • Scherrer, P.H., Bogart, R.S., Bush, R.I., Hoeksema, J.T., Kosovichev, A.G., Schou, J., Rosenberg, W., Springer, L., Tarbell, T.D., Title, A., Wolfson, C.J., Zayer, I., MDI Engineering Team: 1995, The solar oscillations investigation – Michelson Doppler imager. Solar Phys. 162, 129 – 188.

    Article  ADS  Google Scholar 

  • Schunker, H., Cally, P.S.: 2006, Magnetic field inclination and atmospheric oscillations above solar active regions. Mon. Not. Roy. Astron. Soc. 372, 551 – 564.

    Article  ADS  Google Scholar 

  • Schunker, H., Braun, D.C., Cally, P.S.: 2007, Surface magnetic field effects in local helioseismology. Astron. Nachr. 328, 292 – 297.

    Article  ADS  Google Scholar 

  • Schunker, H., Braun, D.C., Cally, P.S., Lindsey, C.: 2005, The local helioseismology of inclined magnetic fields and the showerglass effect. Astrophys. J. 621, L149 – L152.

    Article  ADS  Google Scholar 

  • Shelyag, S., Erdélyi, R., Thompson, M.J.: 2006, Forward modeling of acoustic wave propagation in the quiet solar subphotosphere. Astrophys. J. 651, 576 – 583.

    Article  ADS  Google Scholar 

  • Shelyag, S., Erdélyi, R., Thompson, M.J.: 2007, Forward modelling of sub-photospheric flows for time – distance helioseismology. Astron. Astrophys. 469, 1101 – 1107.

    Article  ADS  Google Scholar 

  • Simmons, B., Basu, S.: 2003, A method for inverting high-degree modes. In: Sawaya-Lacoste, H. (ed.) GONG+ 2002. Local and Global Helioseismology: The Present and Future, SP-517, ESA, Noordwijk, 393 – 396.

    Google Scholar 

  • Thomas, J.H., Cram, L.E., Nye, A.H.: 1982, Five-minute oscillations as a subsurface probe of sunspot structure. Nature 297, 485 – 487.

    Article  ADS  Google Scholar 

  • Thompson, M.J., Zharkov, S.: 2008, Recent developments in local helioseismology. Solar Phys. doi:10.1007/s11207-008-9143-6.

    Google Scholar 

  • Tong, C.H., Thompson, M.J., Warner, M.R., Pain, C.C.: 2003, Helioseismic signals and wave field helioseismology. Astrophys. J. 593, 1242 – 1248.

    Article  ADS  Google Scholar 

  • Werne, J., Birch, A., Julien, K.: 2004, The need for control experiments in local helioseismology. In: Danesy, D. (ed.) SOHO 14 Helio- and Asteroseismology: Towards a Golden Future, SP-559, ESA, Noordwijk, 172 – 181.

    Google Scholar 

  • Woodard, M.F.: 1997, Implications of localized, acoustic absorption for heliotomographic analysis of sunspots. Astrophys. J. 485, 890 – 894.

    Article  ADS  Google Scholar 

  • Zhao, J., Kosovichev, A.G.: 2003, Helioseismic observation of the structure and dynamics of a rotating sunspot beneath the solar surface. Astrophys. J. 591, 446 – 453.

    Article  ADS  Google Scholar 

  • Zhao, J., Kosovichev, A.G.: 2006, Surface magnetism effects in time – distance helioseismology. Astrophys. J. 643, 1317 – 1324.

    Article  ADS  Google Scholar 

  • Zhao, J., Kosovichev, A.G., Duvall, T.L. Jr.: 2001, Investigation of mass flows beneath a sunspot by time – distance helioseismology. Astrophys. J. 557, 384 – 388.

    Article  ADS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. NWRA, CoRA Division, Boulder, CO, USA

    D. C. Braun & A. C. Birch

Authors
  1. D. C. Braun
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. A. C. Birch
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to D. C. Braun.

Additional information

Helioseismology, Asteroseismology, and MHD Connections

Guest Editors: Laurent Gizon and Paul Cally

Rights and permissions

Reprints and permissions

About this article

Cite this article

Braun, D.C., Birch, A.C. Surface-Focused Seismic Holography of Sunspots: I. Observations. Sol Phys 251, 267–289 (2008). https://doi.org/10.1007/s11207-008-9152-5

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11207-008-9152-5

Keywords

Search

Navigation