Abstract
Abstract
Two comparative active regions, NOAA AR 11283 and AR 11654 are studied. Both active regions have big sunspot numbers, and large areas. However, AR 11283 erupted two X-class flares, AR 11654 erupted little flares. Through investigating the evolution of magnetic field, the active region with complex magnetic configuration has more possibility to create big flares. NOAA is National Oceanic and Atmospheric Administration
Subject
General Physics and Astronomy