Longitudinal Structure of the Double Magnetic Cycle

The longitudinal structure of the double magnetic cycle of solar activity has been investigated using Stanford magnetograph data from 1976 to 1996 (cycles 21 and 22). It is shown that both high-frequency and low-frequency sources of the magnetic field are present in the data and that they reach their maxima in longitudinal zones that are separated by 20°. Some longitudinal zones are found to exist in which the high-frequency component is dominant and other longitudinal zones are found in which the low-frequency component is dominant.