Predicting Sunspot Numbers for Solar Cycles 25 and 26

TL;DR

This paper introduces an extended prediction model for solar cycles that forecasts sunspot numbers nearly two cycles in advance, providing insights into future solar activity levels and their implications for space technology.

Contribution

The authors develop the TMLP-extension model, enabling long-term prediction of solar cycles 25 and 26, improving upon previous models by predicting nearly two cycles ahead.

Findings

Cycle 25 predicted maximum sunspot number: 115.1

Cycle 26 predicted maximum sunspot number: 107.3

Both cycles are expected to have similar activity levels as cycle 24

Abstract

The prediction of solar activity is important for advanced technologies and space activities. The peak sunspot number (SSN), which can represent the solar activity, has declined continuously in the past four solar cycles (21$-$24), and the Sun would experience a Dalton-like minimum, or even the Maunder-like minimum, if the declining trend continues in the following several cycles, so that the predictions of solar activity for cycles 25 and 26 are crucial. In Qin & Wu, 2018, ApJ, we established an SSN prediction model denoted as two-parameter modified logistic prediction (TMLP) model, which can predict the variation of SSNs in a solar cycle if the start time of the cycle has been determined. In this work, we obtain a new model denoted as TMLP-extension (TMLP-E), which can predict the solar cycle nearly two cycles in advance, so that the predictions of cycles 25 and 26 are made. It is found that the predicted solar maximum, ascent time, and cycle length are 115.1, 4.84 yr, and 11.06 yr, respectively, for cycle 25, and 107.3, 4.80 yr, and 10.97 yr, respectively, for cycle 26. The solar activities of cycles 25 and 26 are predicted to be at the same level as that of cycle 24, but will not decrease further. We therefore suggest that the cycles 24$-$26 are at a minimum of Gleissberg cycle.