Latitude–temporal evolution of coronal holes in cycles 21–23

The latitude–temporal evolution of coronal holes (CHs) and time variations in CH areas were studied based on a version of several CHs (Tlatov et al., 2014) from 1975 to 2012. It was shown that two systems of magnetic fields (MFs) play the main role in the 11-year cycle evolution: high-latitude large-scale MFs that manifest themselves as a unipolar magnetic field (which are observed as large and long-lived) and lowlatitude small CHs. These two field systems evolve in antiphase with respect to each other, and their minimums shift by 5–6 years. Due to its anomaly, cycle 23 made it possible to indicate that high-latitude largescale and low-latitude local MFs are physically interrelated and regularly alternate in a prolonged 11-year solar cycle.