ANOMALOUS MAGNETIC REGIONS ON THE SUN

Abstract

We studied the anomalous magnetic regions observed near the minima of solar cycles 24 and 25. The peculiarity of these areas was the deviation of their configuration from Hale's law of magnetic polarity and Joy's law about the inclination of the axes of bipolar groups to the latitudinal direction. Therefore, they belong to the class of so-called anti-Hale active regions. We paid special attention to the flare activity of anti-Hale regions, as this is important for forecasting space weather and magnetic storms in the Earth's atmosphere. The detected anomalies of the surface magnetism of the active regions studied by us may indicate the influence of the mechanisms of the deep small-scale dynamo on their evolution. In this regard we analyzed the possible mechanisms of the formation of anti-Hale magnetic regions. In particular, such mechanisms can be the mechanisms of a small-scale magnetic dynamo. In connection with this an urgent problem today is the search for observed evidence of the existence of the theoretically proposed by Brandenburg A. et al. (2012) of a new physical entity – a small-scale magnetic field hidden in the solar depths, excited by two qualitatively different mechanisms of a small-scale dynamo (SSD). The first mechanism is the SSD of macroscopic MHD (SSD1), while the second is the diffusion SSD of classical MHD (SSD2). However, the small contributions of these sources are very difficult to distinguish observationally. To solve this complication, Sokoloff, Khlystova and Abramenko (2015) proposed a test for separating the contributions of two sources based on a statistical probabilistic model. Such an important feature of the differences between of the two SSD is the behavior of the percentage of anti-Hail groups of sunspots (in relation to the total number of spots) in the minima of solar cycles. According to statistical studies of long series of observations Sokoloff, Khlystova and Abramenko (2015) found that the percentage of anti-Haile groups of spots increases during minima of the solar cycles, suggesting in favor of SSD2. We believe that the detected magnetic anomalies of the studied regions may be caused by the influence of a SSD2 in the depths of the convective zone of the Sun, since this source gives the most noticeable contribution to the surface magnetism near cycle minima.