### Abstract

To assess the ability of helioseismology to probe the subsurface structure and magnetic field of sunspots, we need to determine how helioseismic travel times depend on perturbations to sunspot models. Here we numerically simulate the propagation of f, p_{1}, and p_{2} wave packets through magnetic sunspot models. Among the models we considered, a ±50 km change in the height of the Wilson depression and a change in the subsurface magnetic field geometry can both be detected above the observational noise level. We also find that the travel-time shifts due to changes in a sunspot model must be modeled by computing the effects of changing the reference sunspot model, and not by computing the effects of changing the subsurface structure in the quiet-Sun model. For p_{1} modes, the latter is wrong by a factor of four. In conclusion, numerical modeling of MHD wave propagation is an essential tool for interpreting the effects of sunspots on seismic waveforms.

Original language | English (US) |
---|---|

Article number | A130 |

Journal | Astronomy and Astrophysics |

Volume | 558 |

DOIs | |

State | Published - Oct 31 2013 |

### Fingerprint

### Keywords

- Sun: helioseismology
- Sunspots

### ASJC Scopus subject areas

- Astronomy and Astrophysics
- Space and Planetary Science

### Cite this

*Astronomy and Astrophysics*,

*558*, [A130]. https://doi.org/10.1051/0004-6361/201321485

**Helioseismology of sunspots : How sensitive are travel times to the Wilson depression and to the subsurface magnetic field?** / Schunker, H.; Gizon, Laurent; Cameron, R. H.; Birch, A. C.

Research output: Contribution to journal › Article

*Astronomy and Astrophysics*, vol. 558, A130. https://doi.org/10.1051/0004-6361/201321485

}

TY - JOUR

T1 - Helioseismology of sunspots

T2 - How sensitive are travel times to the Wilson depression and to the subsurface magnetic field?

AU - Schunker, H.

AU - Gizon, Laurent

AU - Cameron, R. H.

AU - Birch, A. C.

PY - 2013/10/31

Y1 - 2013/10/31

N2 - To assess the ability of helioseismology to probe the subsurface structure and magnetic field of sunspots, we need to determine how helioseismic travel times depend on perturbations to sunspot models. Here we numerically simulate the propagation of f, p1, and p2 wave packets through magnetic sunspot models. Among the models we considered, a ±50 km change in the height of the Wilson depression and a change in the subsurface magnetic field geometry can both be detected above the observational noise level. We also find that the travel-time shifts due to changes in a sunspot model must be modeled by computing the effects of changing the reference sunspot model, and not by computing the effects of changing the subsurface structure in the quiet-Sun model. For p1 modes, the latter is wrong by a factor of four. In conclusion, numerical modeling of MHD wave propagation is an essential tool for interpreting the effects of sunspots on seismic waveforms.

AB - To assess the ability of helioseismology to probe the subsurface structure and magnetic field of sunspots, we need to determine how helioseismic travel times depend on perturbations to sunspot models. Here we numerically simulate the propagation of f, p1, and p2 wave packets through magnetic sunspot models. Among the models we considered, a ±50 km change in the height of the Wilson depression and a change in the subsurface magnetic field geometry can both be detected above the observational noise level. We also find that the travel-time shifts due to changes in a sunspot model must be modeled by computing the effects of changing the reference sunspot model, and not by computing the effects of changing the subsurface structure in the quiet-Sun model. For p1 modes, the latter is wrong by a factor of four. In conclusion, numerical modeling of MHD wave propagation is an essential tool for interpreting the effects of sunspots on seismic waveforms.

KW - Sun: helioseismology

KW - Sunspots

UR - http://www.scopus.com/inward/record.url?scp=84886576697&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84886576697&partnerID=8YFLogxK

U2 - 10.1051/0004-6361/201321485

DO - 10.1051/0004-6361/201321485

M3 - Article

VL - 558

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

SN - 0004-6361

M1 - A130

ER -