SEARCH FOR LINKS BETWEEN THE CHARACTER OF MAGNETIC FIELDS IN SOLAR ACTIVE REGIONS AND THEIR FLARE PRODUCTIVITY
We analyzed 95 solar active regions at random time moments. 28 analyzed regions were observed by the MDI/SOHO and TRACE instrument sand 67 regions were observed by the HMI and AIA instruments onboard the SDO satellite. We reconstructed potential magnetic field lines in each region. The line-of-sight photospheric magnetograms were used as boundary conditions. The expert group compared reconstructed field lines with magnetic tubes seen in the EUV range. Based on this comparison, wedefined character of the field in each region as potential, nonpotential or ambiguous. An information about flares occurred in these regions was also analyzed. It is found that only 18 % of active regions are potential. Flares of higher than C4.0 class do not occur in potential regions. It is also shown that the probability to determine an occurrence of a strong flare (M or X class) during the next 24 hours after the considered moment is only 16 %, if it is estimated on the base of the field character determination. An additional result is the estimation of an electric current characteristic grow time - 8 hours.