Correlation Between CME Occurrence Rate and Current Helicity in the Global Magnetic Field of Solar Cycle 23

Abstract

We investigate the correlation between the occurrence rate of the monthly coronal mass ejection (CME) and the magnitude of the current helicity in global magnetic field on the photosphere of solar cycle 23. We used the technique introduced by Pevtsov and Latushko (Astrophys. J. 528, 999, 2000) to retrieve the vector magnetic field from longitudinal full-disk magnetograms, but applied a different method to calculate the current helicity and focused on the evolution of the magnitude of current helicity over a full solar cycle. We found that there is a close relationship between the variation of the current helicity in the global magnetic field and that of the monthly CME occurrence rate. This provides further evidence to support that helicity is an important ingredient for solar eruptions.