Helicity Injection in Regions of Various Magnetic Fluxes

In this study, we investigated magnetic helicity injection rates among active regions of various sizes. We analyzed 78 active regions (more than 600 magnetograms), using the vector magnetograms obtained with the Solar Flare TelescopeSolar Flare Telescope of NAOJ and SoHO/MDISOHOMDI magnetogram magnetograms. We used a method proposed by tet{yamamoto:ksn02, yamamoto:ksn04} to evaluate the helicity injection. Magnetic fluxes of analyzed regions are from 2×10^{12} Wb to 4×10^{14} Wb. Unsigned magnetic helicity injection rates are from 10^{19} Wb^2 s^{-1} to 10^{23} Wb^2 s^{-1}. From a scatter plot of the magnetic flux and the unsigned magnetic helicity injection rate, we found that the magnetic helicity injection rate has an upper limit for a given value of the magnetic flux, and this upper limit is inversely proportional to the magnetic flux. We discuss these results with a model of the helicity injection due to helical turbulence tep*[Σ-Effect;][]{yamamoto:lgc98}.