Consistent determination of quasi force-free magnetic fields from observations in solar active regions
نویسنده
چکیده
The classical concept of extrapolating the photospheric magnetic field from line-of-sight measurements B` assuming a pure force-free field is revisited and a new procedure is proposed which is based on: 1) non-vanishing magnetic forces, 2) known horizontal forces from direct measurement of pressure or a related quantity (continuum brightness), 3) a small perturbation to the potential or linear force-free field which matches the B` distribution. Orders of magnitude are estimated from observational data and they show that magnetic forces should be actually as large as expected from dimensional analysis.
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