Dynamic processes occurring in solar active regions are dominated by the solar magnetic field. As of now, observations using a solar magnetograph have supplied us with the vector components of a solar photospheric magnetic field. The two transverse components of a photospheric magnetic field allow us to compute the amount of electric current. We found that the electric current in areas with positive （negative） polarity due to the longitudinal magnetic field have both positive and neg- ative signs in an active region, however, the net current is found to be an order-of- magnitude less than the mean absolute magnitude and has a preferred sign. In particu- lar, we have statistically found that there is a systematic net electric current from areas with negative （positive） polarity to areas with positive （negative） polarity in solar ac- tive regions in the northern （southern） hemisphere, but during the solar minimum this tendency is reversed over time at some latitudes. The result indicates that there is weak net electric current in areas of solar active regions with opposite polarity, thus provid- ing further details about the hemispheric helicity rule found in a series of previous studies.
Two groups of microwave type U and Reverse-Slope(RS)bursts after the Soft X-Ray(SXR)maximum were observed with the 2.6~3.8GHz spectrometer of Chinese Solar Broadband Radio Spectrometers(SBRS/Huairou)on 15 February 2011,when an X2.2 solar flare occurred in the Active Region(AR)NOAA 11158.A Shear-driven Quadrupolar Reconnection(SQR)model was utilized to analyze these bursts and the two loops involved were found to be basically in the same spatial scale and have a height difference of about 1300 km.These bursts were interpreted to be a result of a new reconnection process between the two similar-scaled loops.
