JapaneseGEMSIS-Sun
Storage and Release Processes of Magnetic Field Energy and Magnetic Helicity in the Solar Atmosphere
Magnetic shear is a major energy source for active solar phenomena. We tried to reproduce the soft X-ray light curves of flares using magnetic shears measured on the photosphere. The shear field strengths of the flare samples were applied from our previous papers (Yamamoto and Sakurai, 2009). The supplied figure shows the observed and calculated light curves. We successfully reproduced light curves similar to observations. From these results, we can provide a scenario for the down-flow motions observed above flare loops. So far, it is difficult to provide a quantitative reason for the velocities of the down-flow motions. These results are published as Yamamoto and Sakurai (2010).
We discussed interpretations of helicity injection equations with the aim of separating the helicity injection rate into rates for the positive and negative magnetic polarities in the photosphere. Originally, the helicity injection rate was defined as the area-integrated value (Berger and Field, 1984). This integrated area includes both the positive and negative polarities. We found that it is possible to obtain helicity injection fluxes on the positive and negative polarities by separating the vector potential into separate portions for the positive and negative polarities. The results are published in Yamamoto (2011).