caa a22 4500 445346442 CHVBK 20180317142830.0 cr unu---uuuuu 170323e20110901xx s 000 0 eng 10.1007/s11207-011-9826-2 doi (NATIONALLICENCE)springer-10.1007/s11207-011-9826-2 Estimating the Relative Helicity of Coronal Magnetic Fields [Elektronische Daten] [J. Thalmann, B. Inhester, T. Wiegelmann] To quantify changes of the solar coronal field connectivity during eruptive events, one can use magnetic helicity, which is a measure of the shear or twist of a current-carrying (non-potential) field. To find a physically meaningful quantity, a relative measure, giving the helicity of a current-carrying field with respect to a reference (potential) field, is often evaluated. This requires a knowledge of the three-dimensional vector potential. We present a method to calculate the vector potential for a solenoidal magnetic field as the sum of a Laplacian part and a current-carrying part. The only requirements are the divergence freeness of the Laplacian and current-carrying magnetic field and the sameness of their normal field component on the bounding surface of the considered volume. Springer Science+Business Media B.V., 2011 Helicity, magnetic nationallicence Magnetic fields, corona nationallicence Thalmann J. Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Str. 2, 37191, Katlenburg-Lindau, Germany aut Inhester B. Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Str. 2, 37191, Katlenburg-Lindau, Germany aut Wiegelmann T. Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Str. 2, 37191, Katlenburg-Lindau, Germany aut Solar Physics Springer Netherlands 272/2(2011-09-01), 243-255 0038-0938 272:2<243 2011 272 11207 https://doi.org/10.1007/s11207-011-9826-2 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11207-011-9826-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Thalmann J. Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Str. 2, 37191, Katlenburg-Lindau, Germany aut NATIONALLICENCE 700 1- Inhester B. Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Str. 2, 37191, Katlenburg-Lindau, Germany aut NATIONALLICENCE 700 1- Wiegelmann T. Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Str. 2, 37191, Katlenburg-Lindau, Germany aut NATIONALLICENCE 773 0- Solar Physics Springer Netherlands 272/2(2011-09-01), 243-255 0038-0938 272:2<243 2011 272 11207 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer