Változó naptevékenység

The long-term behaviour of solar magnetic fields, the properties of solar dynamo process can be studied mostly by examining spatial and temporal patterns of sunspots, the tools of this work are the sunspot catalogues of Greenwich and Debrecen. Among the achievements of the recent years the following results are worth mentioning: the 4+4 cycle period of the phaselags of solar hemispheric cycles, the non-axisymmetry of spot emergence and its dynamics, the connection of Spörer-diagram with the velocity field of torsional oscillation, evidences for the long-term variation of solar activity, and as a new progress, flare-forecast investigations by using high-resolution sunspot data.