Sunspot decay as a test of the eta-quenching concept

A 2D model of the sunspot decay is constructed which under the assumption o f axial symmetry follows the evolution of both the magnetic field and tempe rature. Magnetic-induced deformation and suppression of the tensors of turb ulent heat conductivity and eddy diffusivity are explicitly included. In an older model without the eta-quenching the decay law of spot area proved to be slightly convex with (A) double over dot < 0 in contrast to the results of new and detailed investigations of the observations. With the eta-quenc hing involved, our models do not exhibit the convex decay laws but instead yield quasilinear decays for both the spot area as well as the magnetic flu x (cf. Fig. 3).