A Quantitative Study on Magnetic Configuration for Active Regions

Abstract

As compared with the Mount Wilson Magnetic Classification (MWMC), effective distance (d_E) is a useful parameter because it gives a quantitative measure of magnetic configuration in active regions. We have analyzed magnetograms of 24 active regions of different types with MWMC. We have studied the evolution of magnetic fields of five active regions using d_E, total flux (F_t) and tilt angle (Tilt) quantitatively. Furthermore, 43 flare-associated and 25 CME-associated active regions have been studied to investigate and quantify the statistical correlation between flares/CMEs and the three parameters. The main results are as follows: (1) There is a basic agreement between d_E and MWMC. (2) The evolution of magnetic fields can be described in three aspects quantitatively and accurately by the three parameters, in particular by d_E on the analysis of δ-type active regions. (3) The high correlation between d_E and flares/CMEs means that d_E could be a promising measure to predict the flare-CME activity of active regions.