Published on the blog of the National Solar Observatory the article "Prediction of Sunspot and Plage Coverage for Solar Cycle 25", concerning the forecasts on solar activity relating to the 25th cycle, previously published in The Astrophysical Journal Letters, Volume 922, Number 1. Among the signatures of the article for the Physics Department of the University of Rome “Tor Vergata” (solar physics group) there are: Prof. Francesco Berrilli, Dr. Valentina Penza, Dr. Matteo Cantoresi.


Below is the abstract of the article:

Solar variability occurs over a broad range of spatial and temporal scales, from the Sun’s brightening over its lifetime to the fluctuations commonly associated with magnetic activity over minutes to years. The latter activity includes most prominently the 11 yr sunspot solar cycle and its modulations. Space weather events, in the form of solar flares, solar energetic particles, coronal mass ejections, and geomagnetic storms, have long been known to approximately follow the solar cycle occurring more frequently at solar maximum than solar minimum. These events can significantly impact our advanced technologies and critical infrastructures, making the prediction for the strength of future solar cycles particularly important. Several methods have been proposed to predict the strength of the next solar cycle, cycle XXV, with results that are generally not always consistent. Most of these methods are based on the international sunspot number time series, or other indicators of solar activity. We present here a new approach that uses more than 100 yr of measured fractional areas of the visible solar disk covered by sunspots and plages and an empirical relationship for each of these two indices of solar activity in even–odd cycles. We anticipate that cycle XXV will peak in 2024 and will last for about 12 yr, slightly longer than cycle XXIV. We also found that, in terms of sunspot and plage areas coverage, the amplitude of cycle XXIV will be substantially similar or slightly higher than cycle XXIV.