Comparisons between current sheet location and three-spacecraft white-light tomography results

Abstract:

In order to better understand and predict the solar coronal activity that drives space weather, we must be able to accurately infer the characteristics of the coronal magnetic field. While efforts to model the solar corona have made significant progress in recent decades, there continue to be significant discrepancies between coronal magnetic field models based on different input driver maps and using different physical assumptions, parameter settings, and/or solution techniques. This has led to the need for techniques to discriminate amongst models using available remote sensing and in situ measurements.

Another area where significant progress has been made in recent decades is in the reconstruction of the coronal electron density using rotational tomography. This technique takes advantage of the fact that the observed intensity in white-light coronagraph images is a line-of-sight integral of the electron density, and a series of images taken from different vantage points are used to mathematically reconstruct that density in three dimensions. Here we will present a quantitative method for comparing the location of a modelled heliospheric current sheet to the reconstructed coronal electron density by a regularized tomography technique from white-light pB data obtained with the SOHO LASCO/C2 and STEREO COR1-A and -B coronagraphs. Examples will be presented using both different input maps and parameter settings in the Wang-Sheeley-Arge (WSA) model.