Ap. J., 577 (2002) 993-1005. link

Complete models of axisymmetric sunspots: magnetoconvection with coronal heating

N.E. Hurlburt (1), D. Alexander (1) and A.M. Rucklidge (2).

(1) Lockheed Martin Solar and Astrophysics Laboratory,
Organization L9-41 Building 252, Palo Alto, CA 94304, USA

(2) Department of Applied Mathematics,
University of Leeds, Leeds, LS2 9JT, UK

Abstract. We present detailed results of numerical experiments into the nature of complete sunspots. The models remain highly idealized but include fully nonlinear compressible magnetoconvection in an axisymmetric layer that drives energy into an overlying, low-beta plasma. We survey a range of parameters in which the resulting magnetoconvection displays the formation of pore- and sunspot-like behavior and assess the coronal signatures resulting from the energy generated by the magnetoconvection. The coronal heating is assumed to be a result of the dissipation by an unspecified means of a fraction of the Poynting flux entering the corona. The expected signatures in the EUV and soft X-ray bandpasses of the Transition Region and Coronal Explorer and Yohkoh/SXT, respectively, are examined. This ad hoc coupling of the corona to the subphotospheric region results in a dynamical behavior that is consistent with recent observational results. This agreement demonstrates that even simple coupled modeling can lead to diagnostics for investigations of both subphotospheric sunspot structures and coronal heating mechanisms.

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