Secular Solar Minimum Predicted by Galactic Cosmic Radiation Modulation

A trend of cycle-to-cycle decline in solar activity started at the end of cycle 21, after several cycles of elevated solar activity (secular maximum) coinciding with the space age. In this study, we investigate the possibility that such decline, which has persisted through the current transition from cycle 24 to cycle 25, is shaping into a modern era secular minimum. We study the correlation between the modulation of the galactic cosmic rays and solar wind parameters for the last 24 solar cycles to find possible trends. We show that it is likely that we have already entered a secular minimum, which, based on historical records, might last for another two cycles (25 and 26). We further show that cycle 25 will be slightly weaker than cycle 24.