Skip to main content
Log in

Global-Oscillation Eigenfunction Measurements of Solar Meridional Flow

  • SOLAR DYNAMICS AND MAGNETISM
  • Published:
Solar Physics Aims and scope Submit manuscript

Abstract

We describe and apply a new helioseismic method for measuring solar subsurface axisymmetric meridional and zonal flow. The method is based on a theoretical model of the response of global-oscillation eigenfunctions to the flow velocity and uses cross spectra of the time-varying coefficients in the spherical-harmonic expansion of the photospheric Doppler-velocity field. Eigenfunction changes modify the leakage matrix, which describes the sensitivity of the spherical-harmonic coefficients to the global-oscillation modes. The form of the leakage matrix in turn affects the theoretically expected spherical-harmonic cross spectra. Estimates of internal meridional and zonal flow were obtained by fitting the theoretical flow-dependent cross spectra to spherical-harmonic cross spectra computed from approximately 500 days of full-disk Dopplergrams from the Helioseismic and Magnetic Imager (HMI) on the SDO spacecraft. The zonal-flow measurements, parameterized in the form of “a” coefficients, substantially agree with measurements obtained from conventional global-mode-frequency analysis. The meridional-flow estimates, in the form of depth-weighted averages of the flow velocity, are similar to estimates obtained from earlier analyses, for oscillation modes that penetrate the outermost one-third of the convection zone. For more deeply penetrating modes, the inferred flow velocity increases significantly with penetration depth, indicating the need for either a modification of the simple conveyor-belt picture of meridional flow or improvement in the cross-spectral model.

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

Access this article

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

Instant access to the full article PDF.

Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11
Figure 12
Figure 13
Figure 14
Figure 15
Figure 16
Figure 17

Similar content being viewed by others

References

  • Anderson, E.R., Duvall, T.L. Jr., Jefferies, S.M.: 1990, Modeling of solar oscillation power spectra. Astrophys. J. 364, 699 – 705. doi: 10.1086/169452 .

    Article  ADS  Google Scholar 

  • Braun, D.C., Birch, A.C.: 2008, Prospects for the detection of the deep solar meridional circulation. Astrophys. J. Lett. 689, L161 – L165. doi: 10.1086/595884 .

    Article  ADS  Google Scholar 

  • Braun, D.C., Fan, Y.: 1998, Helioseismic measurements of the subsurface meridional flow. Astrophys. J. Lett. 508, L105 – L108. doi: 10.1086/311727 .

    Article  ADS  Google Scholar 

  • Braun, D.C., Fan, Y.: 1999, Erratum: helioseismic measurements of the subsurface meridional flow. Astrophys. J. Lett. 510, L81. doi: 10.1086/311804 .

    Article  ADS  Google Scholar 

  • Chatterjee, P., Antia, H.M.: 2009, Solar flows and their effect on frequencies of acoustic modes. Astrophys. J. 707, 208 – 217. doi: 10.1088/0004-637X/707/1/208 .

    Article  ADS  Google Scholar 

  • Chou, D.-Y., Ladenkov, O.: 2005, Evolution of solar subsurface meridional flows in the declining phase of Cycle 23. Astrophys. J. 630, 1206 – 1212. doi: 10.1086/432372 .

    Article  ADS  Google Scholar 

  • Dikpati, M., Gilman, P.A.: 2006, Simulating and predicting solar cycles using a flux-transport dynamo. Astrophys. J. 649, 498 – 514. doi: 10.1086/506314 .

    Article  ADS  Google Scholar 

  • Duvall, T.L. Jr.: 1979, Large-scale solar velocity fields. Solar Phys. 63, 3 – 15. doi: 10.1007/BF00155690 .

    Article  ADS  Google Scholar 

  • Duvall, T.L. Jr., Hanasoge, S.M.: 2009, Measuring meridional circulation in the Sun. In: Dikpati, M., Arentoft, T., González Hernández, I., Lindsey, C., Hill, F. (eds.) Solar-Stellar Dynamos as Revealed by Helio- and Asteroseismology: GONG 2008/SOHO 21 CS-416, Astron. Soc. Pac., San Francisco, 103.

    Google Scholar 

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

  • Giles, P.M., Duvall, T.L. Jr., Scherrer, P.H.: 1998, Time–distance measurements of subsurface rotation and meridional flow. In: Korzennik, S. (ed.) Structure and Dynamics of the Interior of the Sun and Sun-like Stars SP-418, ESA, Noordwijk, 775.

    Google Scholar 

  • Giles, P.M., Duvall, T.L., Scherrer, P.H., Bogart, R.S.: 1997, A subsurface flow of material from the Sun’s equator to its poles. Nature 390, 52 – 54. doi: 10.1038/36294 .

    Article  ADS  Google Scholar 

  • Gizon, L., Birch, A.C.: 2004, Time–distance helioseismology: Noise estimation. Astrophys. J. 614, 472 – 489. doi: 10.1086/423367 .

    Article  ADS  Google Scholar 

  • Gizon, L., Duvall, T.L., Schou, J.: 2003a, Wave-like properties of solar supergranulation. Nature 421, 43 – 44.

    Article  ADS  Google Scholar 

  • Gizon, L., Duvall, T.L. Jr., Schou, J.: 2003b, Erratum: wave-like properties of solar supergranulation. Nature 421, 764.

    Article  ADS  Google Scholar 

  • González Hernández, I., Patrón, J., Bogart, R.S., The SOI Ring Diagram Team: 1999, Meridional flows from ring diagram analysis. Astrophys. J. Lett. 510, L153 – L156. doi: 10.1086/311811 .

    Article  ADS  Google Scholar 

  • Gough, D., Hindman, B.W.: 2010, Helioseismic detection of deep meridional flow. Astrophys. J. 714, 960 – 970. doi: 10.1088/0004-637X/714/1/960 .

    Article  ADS  Google Scholar 

  • Haber, D.A., Hindman, B.W., Toomre, J., Bogart, R.S., Larsen, R.M., Hill, F.: 2002, Evolving submerged meridional circulation cells within the upper convection zone revealed by ring-diagram analysis. Astrophys. J. 570, 855 – 864. doi: 10.1086/339631 .

    Article  ADS  Google Scholar 

  • Harvey, J.W., Hill, F., Hubbard, R.P., Kennedy, J.R., Leibacher, J.W., Pintar, J.A., Gilman, P.A., Noyes, R.W., Title, A.M., Toomre, J., Ulrich, R.K., Bhatnagar, A., Kennewell, J.A., Marquette, W., Patron, J., Saa, O., Yasukawa, E.: 1996, The Global Oscillation Network Group (GONG) project. Science 272, 1284 – 1286. doi: 10.1126/science.272.5266.1284 .

    Article  ADS  Google Scholar 

  • Hathaway, D.H.: 2011, The Sun’s shallow meridional circulation. arXiv:1103.1561 .

  • Hughes, S.J., Thompson, M.J.: 2003, Time–distance helioseismology of subsurface flows. In: Sawaya-Lacoste, H. (ed.) GONG 2002. Local and Global Helioseismology: The Present and Future SP-517, ESA, Noordwijk, 307 – 310.

    Google Scholar 

  • Korzennik, S.G., Rabello-Soares, M.C., Schou, J.: 2004, On the determination of Michelson Doppler imager high-degree mode frequencies. Astrophys. J. 602, 481 – 516. doi: 10.1086/381021 .

    Article  ADS  Google Scholar 

  • Labonte, B.J., Howard, R.: 1982, Solar rotation measurements at Mount Wilson. III–Meridional flow and limbshift. Solar Phys. 80, 361 – 372. doi: 10.1007/BF00147982 .

    Article  ADS  Google Scholar 

  • Lavely, E.M., Ritzwoller, M.H.: 1992, The effect of global-scale, steady-state convection and elastic-gravitational asphericities on helioseismic oscillations. Phil. Trans. Roy. Soc. London A 339, 431 – 496.

    Article  ADS  Google Scholar 

  • Miesch, M.S., Elliott, J.R., Toomre, J., Clune, T.L., Glatzmaier, G.A., Gilman, P.A.: 2000, Three-dimensional spherical simulations of solar convection. I. Differential rotation and pattern evolution achieved with laminar and turbulent states. Astrophys. J. 532, 593 – 615. doi: 10.1086/308555 .

    Article  ADS  Google Scholar 

  • Ritzwoller, M.H., Lavely, E.M.: 1991, A unified approach to the helioseismic forward and inverse problems of differential rotation. Astrophys. J. 369, 557 – 566. doi: 10.1086/169785 .

    Article  ADS  Google Scholar 

  • Roth, M., Stix, M.: 2008, Meridional circulation and global solar oscillations. Solar Phys. 251, 77 – 89. doi: 10.1007/s11207-008-9232-6 .

    Article  ADS  Google Scholar 

  • Schad, A., Timmer, J., Roth, M.: 2011, A unified approach to the helioseismic inversion problem of the solar meridional flow from global oscillations. Astrophys. J. 734, 97. doi: 10.1088/0004-637X/734/2/97 .

    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. doi: 10.1007/BF00733429 .

    Article  ADS  Google Scholar 

  • Schou, J.: 1992, On the analysis of helioseismic data. PhD thesis, Aarhus University, Aarhus, Denmark [S92].

  • Schou, J.: 2003, Wavelike properties of solar supergranulation detected in Doppler shift data. Astrophys. J. Lett. 596, L259 – L262. doi: 10.1086/379529 .

    Article  ADS  Google Scholar 

  • Schou, J., Bogart, R.S.: 1998, Flow and horizontal displacements from ring diagrams. Astrophys. J. Lett. 504, L131. doi: 10.1086/311575 .

    Article  ADS  Google Scholar 

  • Schou, J., Brown, T.M.: 1994, Generation of artificial helioseismic time-series. Astron. Astrophys. Suppl. 107, 541 – 550.

    ADS  Google Scholar 

  • Schou, J., Christensen-Dalsgaard, J., Thompson, M.J.: 1994, On comparing helioseismic two-dimensional inversion methods. Astrophys. J. 433, 389 – 416. doi: 10.1086/174653 .

    Article  ADS  Google Scholar 

  • Schou, J., Scherrer, P.H., Bush, R.I., Wachter, R., Couvidat, S., Rabello-Soares, M.C., Bogart, R.S., Hoeksema, J.T., Liu, Y., Duvall, T.L., Akin, D.J., Allard, B.A., Miles, J.W., Rairden, R., Shine, R.A., Tarbell, T.D., Title, A.M., Wolfson, C.J., Elmore, D.F., Norton, A.A., Tomczyk, S.: 2012, Design and ground calibration of the Helioseismic and Magnetic Imager (HMI) instrument on the Solar Dynamics Observatory (SDO). Solar Phys. 275, 229 – 259. doi: 10.1007/s11207-011-9842-2 .

    Article  ADS  Google Scholar 

  • Sheeley, N.R. Jr.: 2005, Surface evolution of the Sun’s magnetic field: A historical review of the flux-transport mechanism. Living Rev. Solar Phys. 2, 5. http://www.livingreviews.org/lrsp-2005-5 .

    Article  ADS  Google Scholar 

  • Sivaraman, K.R., Sivaraman, H., Gupta, S.S., Howard, R.F.: 2010, Return meridional flow in the convection zone from latitudinal motions of umbrae of sunspot groups. Solar Phys. 266, 247 – 259. doi: 10.1007/s11207-010-9620-6 .

    Article  ADS  Google Scholar 

  • Unno, W., Osaki, Y., Ando, H., Saio, H., Shibahashi, H.: 1989, Nonradial Oscillations of Stars, Univ. of Tokyo Press, Tokyo.

    Google Scholar 

  • Vorontsov, S.V.: 2007, Solar p modes of high degree l: Coupling by differential rotation. Mon. Not. Roy. Astron. Soc. 378, 1499 – 1506. doi: 10.1111/j.1365-2966.2007.11894.x .

    Article  ADS  Google Scholar 

  • Vorontsov, S.V.: 2011, Effects of differential rotation and meridional circulation in solar oscillations of high degree l. Mon. Not. Roy. Astron. Soc. 418, 1146 – 1155. doi: 10.1111/j.1365-2966.2011.19564.x [V11].

    Article  ADS  Google Scholar 

  • Woodard, M.F.: 1989, Distortion of high-degree solar p-mode eigenfunctions by latitudinal differential rotation. Astrophys. J. 347, 1176 – 1182. doi: 10.1086/168206 .

    Article  ADS  Google Scholar 

  • Woodard, M.F.: 2000, Theoretical signature of solar meridional flow in global seismic data. Solar Phys. 197, 11 – 20. doi: 10.1023/A:1026508211960 .

    Article  ADS  Google Scholar 

  • Woodard, M.F.: 2007, Probing supergranular flow in the solar interior. Astrophys. J. 668, 1189 – 1195. doi: 10.1086/521391 .

    Article  ADS  Google Scholar 

  • Woodard, M.F.: 2009, Helioseismic measurement of large-scale solar flows. In: Dikpati, M., Arentoft, T., González Hernández, I., Lindsey, C., Hill, F. (eds.) Solar-Stellar Dynamos as Revealed by Helio- and Asteroseismology: GONG 2008/SOHO 21 CS-416, Astron. Soc. Pac., San Francisco, 15.

    Google Scholar 

  • Zhao, J., Kosovichev, A.G.: 2004, Torsional oscillation, meridional flows, and vorticity inferred in the upper convection zone of the sun by time–distance helioseismology. Astrophys. J. 603, 776 – 784. doi: 10.1086/381489 .

    Article  ADS  Google Scholar 

Download references

Acknowledgements

We thank Doug Braun for useful discussions and Ashley Crouch for useful discussions and calculations. HMI data are courtesy of NASA/SDO and the HMI science team. This research was supported by NASA contracts NAS5-03114 and NNH09CF93C to NWRA/CoRA. HMI is supported by NASA contract NAS5-02139 to Stanford University.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to M. Woodard.

Additional information

Solar Dynamics and Magnetism from the Interior to the Atmosphere

Guest Editors: R. Komm, A. Kosovichev, D. Longcope, and N. Mansour

Rights and permissions

Reprints and permissions

About this article

Cite this article

Woodard, M., Schou, J., Birch, A.C. et al. Global-Oscillation Eigenfunction Measurements of Solar Meridional Flow. Sol Phys 287, 129–147 (2013). https://doi.org/10.1007/s11207-012-0075-9

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11207-012-0075-9

Keywords

Navigation