Near-Surface Azimuthal Magnetic Fields and Their Role in Solar Activity Cycles

We consider variations of the azimuthal magnetic fields of the Sun in the 23 – 25 activity cycles according to observations with SDO/HMI, SOHO/MDI, and Kislovodsk/STOP telescopes. To identify azimuthal magnetic fields, the daily observations of LOS magnetic fields from the regions near the solar limb were analyzed. It is shown that with a sufficiently large averaging of the data, large-scale structures are distinguished, which can be interpreted by horizontal magnetic fields along the east – west direction. Azimuthal magnetic fields are visible at both low and high latitudes. Azimuthal fields at the same latitudes have opposite directions in the northern and southern hemispheres and also change sign in even and odd cycles of activity.