2017/01/17 by K. D. Leka, G. Barnes, E. L. Wagner · 1 citation
Physics and Astronomy · #astro-ph.SR #astro-ph.IM
paper · pdf · doi:10.1007/s11207-017-1057-8
Accepted for publication in Solar Physics
arxiv created 2017/01/17 · arxiv updated 2017/02/22
Although for many solar physics problems the desirable or meaningful boundary is the radial component of the magnetic field B\rm r, the most readily available measurement is the component of the magnetic field along the line-of-sight to the observer, B\rm los. As this component is only equal to the radial component where the viewing angle is exactly zero, some approximation is required to estimate B\rm r at all other observed locations. In this study, a common approximation known as the "μ-correction", which assumes all photospheric field to be radial, is compared to a method which invokes computing a potential field that matches the observed B\rm los, from which the potential field radial component, B\rm r\rm pot is recovered. We demonstrate that in regions that are truly dominated by radially-oriented field at the resolution of the data employed, the μ-correction performs acceptably if not better than the potential-field approach. However, it is also shown that for any solar structure which includes horizontal fields, i.e. active regions, the potential-field method better recovers both the strength of the radial field and the location of magnetic neutral line.