caa a22 4500 445345810 CHVBK 20180317142828.0 cr unu---uuuuu 170323e20110201xx s 000 0 eng 10.1007/s11207-010-9631-3 doi (NATIONALLICENCE)springer-10.1007/s11207-010-9631-3 Constructing Semi-Empirical Sunspot Models forHelioseismology [Elektronische Daten] [R. Cameron, L. Gizon, H. Schunker, A. Pietarila] One goal of helioseismology is to determine the subsurface structure of sunspots. In order to do so, it is important to understand first the near-surface effects of sunspots on solar waves, which are dominant. Here we construct simplified, cylindrically-symmetric sunspot models that are designed to capture the magnetic and thermodynamics effects coming from about 500km below the quiet-Sun τ 5000=1 level to the lower chromosphere. We use a combination of existing semi-empirical models of sunspot thermodynamic structure (density, temperature, pressure): the umbral model of Maltby et al. (1986, Astrophys. J. 306, 284) and the penumbral model of Ding and Fang (1989, Astron. Astrophys. 225, 204). The OPAL equation-of-state tables are used to derive the sound-speed profile. We smoothly merge the near-surface properties to the quiet-Sun values about 1Mm below the surface. The umbral and penumbral radii are free parameters. The magnetic field is added to the thermodynamic structure, without requiring magnetostatic equilibrium. The vertical component of the magnetic field is assumed to have a Gaussian horizontal profile, with a maximum surface field strength fixed by surface observations. The full magnetic-field vector is solenoidal and determined by the on-axis vertical field, which, at the surface, is chosen such that the field inclination is 45° at the umbral - penumbral boundary. We construct a particular sunspot model based on SOHO/MDI observations of the sunspot in active region NOAA 9787. The helioseismic signature of the model sunspot is studied using numerical simulations of the propagation of f, p 1, and p 2 wave packets. These simulations are compared against cross-covariances of the observed wave field. We find that the sunspot model gives a helioseismic signature that is similar to the observations. Springer Science+Business Media B.V., 2010 Sun: helioseismology nationallicence Sun: sunspots nationallicence Sun: magnetic fields nationallicence Cameron R. Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Straße 2, 37191, Katlenburg-Lindau, Germany aut Gizon L. Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Straße 2, 37191, Katlenburg-Lindau, Germany aut Schunker H. Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Straße 2, 37191, Katlenburg-Lindau, Germany aut Pietarila A. Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Straße 2, 37191, Katlenburg-Lindau, Germany aut Solar Physics Springer Netherlands 268/2(2011-02-01), 293-308 0038-0938 268:2<293 2011 268 11207 https://doi.org/10.1007/s11207-010-9631-3 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11207-010-9631-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Cameron R. Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Straße 2, 37191, Katlenburg-Lindau, Germany aut NATIONALLICENCE 700 1- Gizon L. Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Straße 2, 37191, Katlenburg-Lindau, Germany aut NATIONALLICENCE 700 1- Schunker H. Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Straße 2, 37191, Katlenburg-Lindau, Germany aut NATIONALLICENCE 700 1- Pietarila A. Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Straße 2, 37191, Katlenburg-Lindau, Germany aut NATIONALLICENCE 773 0- Solar Physics Springer Netherlands 268/2(2011-02-01), 293-308 0038-0938 268:2<293 2011 268 11207 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer