I derived a geometrical model of the penumbral magnetic field topology froman uncombed inversion setup that aimed at reproducing the NCP of simultaneousspectra in near-IR (1.56 mu) and VIS (630 nm) spectral lines. I inverted thespectra of five photospheric lines with a model that mimicked verticallyinterlaced magnetic fields with two components, labeled background field andflow channels. The flow channels were modeled as a perturbation of thebackground field with a Gaussian shape using the SIRGAUS code. The location andextension of the Gaussian perturbation in the optical depth scale was thenconverted to a geometrical height scale. I investigated the relative amount ofmagnetic flux in the flow channels and the background field atmosphere. Theuncombed model is able to reproduce the NCP well on the limb side of the spotand worse on the center side; the VIS lines are better reproduced than thenear-IR lines. The Evershed flow happens along nearly horizontal field linesclose to the solar surface. The magnetic flux that is related to the flowchannels makes up about 20-50% of the total magnetic flux in the penumbra. Thegradients obtainable by a Gaussian perturbation are too small for a perfectreproduction of the NCP in the IR lines with their small formation heightrange. Two peculiarities of the observed NCP, a sign change of the NCP of theVIS lines on the center side and a ring structure around the umbra in the Tiline at 630.37nm and the FeI line at 1565.2nm deserve closer attention. Thelarge fraction of magnetic flux related to the flow channel component couldallow to replenish the penumbral radiative losses in the flux tube picture.
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