ПІВНІЧНО-ПІВДЕННА АСИМЕТРІЯ АКТИВНОСТІ СОНЯЧНИХ ПЛЯМ ПІД ЧАС МІНІМУМУ МАУНДЕРА

An important key to studying the impact of solar activity variations on the Earth’s climate is the Maunder Minimum (late 17th century), during which extremely little sunspots were observed. Applying the rare event analysis method to these observations led the researchers to conclude that the appearance of sunspots during the Maunder minimum had a weak amplitude 22-year cycle. The concept of continuity of magnetic cycles at this time is also confirmed by measurements of cosmogenic radionuclides in natural terrestrial archives. Therefore, today it is believed that during the Maunder Minimum, the cyclic magnetic activity of the Sun did not stop, although the amplitude of the cycles was quite low. In the αΩ dynamo model, this may be due to the fact that the magnitude of the magnetic induction of the toroidal field, excited by radial differential rotation in the solar convection zone (SCZ), at this time did not reach the threshold value required for lifting magnetic power tubes to the solar surface (nonlinear dynamo mode). Possible physical mechanisms describing the suppression of the dynamo process at time intervals, when no sunspots were observed, are analysed. A scenario for explaining the north-south asymmetry of magnetic activity during the Maunder Minimum is proposed. A key role in the proposed scenario is played by the special nature of the internal rotation of the Sun, revealed in the helioseismological experiments. According to helioseismology data, the SCZ is naturally divided into polar and equatorial domains with opposite signs of the radial angular velocity gradient. In addition, the radial angular velocity gradient penetrates into the deep layers of the stable radiant zone below the SCZ. It is shown that, taking into account these helioseismology data, the αΩ dynamo excites two harmonics (dipole and quadrupole) of the toroidal magnetic field in the SCZ, which cyclically change their direction. The αΩ dynamo excites two harmonics (dipole and quadrupole) of the toroidal field in the RMS, which cyclically change their direction. At the same time, the deep Ω effect in the radiant zone creates the toroidal field of stationary orientation. The summary toroidal magnetic field (the dynamo-field of the SCZ + the field of the radiant zone) rising to the Sun’s surface due to magnetic buoyancy may contribute to the north-south asymmetry in sunspot activity.