05-10-2013 from Morten Franz

The plasma flow in and around sunspots

The horizontal plasma outflow in the Penumbrae of Sunspots (the Evershed effect) is known for more than 100 Years. However, a radial outflow is not only present within the penumbra, but also in the so-called moat region, surrounding the sunspot. We investigated these flows using spectroscopic HINODE observation. After a wavelength calibration, we obtained the Doppler velocities from the shift of the wing of the solar spectral line of Fe I at 630.15 nm (see Picture 1). In a second step, the velocity signal was extracted along elliptical paths in and around the sunspot, before a sinusoidal...(Read more)

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