Cycle 25 progression as observed by GONG magnetographs

 Time vs. solar latitude diagram of the radial component of solar magnetic field for 2006-2025. Each column represents one solar rotation (Carrington map). Blue/red show negative/positive polarity fields scaled between ±5 Gauss. Mid-latitude ( ±30 degrees) patters in both hemispheres correspond to the solar active regions. As solar cycle progresses, the latitude of active region formation drifts from higher to lower latitudes. Originating from these active region belts are diffused patterns drifting towards the solar poles. These are the remnants of trailing polarity fields of active regions, so called poleward surges, which gradually cancel out the polar fields of previous cycle and build-up new polar field of next solar cycle. In active regions, the leading polarity field is typically stronger, and it is more compact in comparison with the following polarity field. Also, the sign of the leading polarity fields in active regions is the  hemisphere and cycle dependent (so called, Hale polarity rule). This explains the sign-asymmetry in active region belts on this map: in cycle 24, the mid-latitude belt in the northern hemisphere appears mostly positive, while in the southern hemisphere, it is mostly negative. This polarity sign-preference reverses for cycle 25 with the mid-latitude belt in the northern/southern hemisphere appearing mostly negative/positive. The active region belts represent the 11-year (sunspot) cycle, which when combined with the sign-reversal of leading polarities of active regions in consecutive cycles (the Hale polarity rule) and the polar field evolution forms a 22-year magnetic cycle of the Sun. Data are acquired by GONG instruments operated by NISP/NSO/AURA/NSF.