Can the 25th Solar Cycle be a new Dalton minimum?*

(By Gani Caglar Coban, Abd-ur Raheem, Huseyin Cavus, and Mahboubeh Asghari-Targhi)

Abstract

The objective of this study is to predict the solar activity for the coming 10 years (25 th solar cycle) using a deep learning technique known as stateful Long Short-Term Memory Network (LSTM). To achieve this goal the number of daily sunspots observed by the American Association of Variable Star Observers (AAVSO) organization from 1945 to 2020 are used as training data for a stateful LSTM model created in the R programming language using Keras (Chollet et al, 2015) library in this study. Time slices are produced by dividing the data between 1945-2020 and data was predicted and examined for the test years of the network trained on these time slices. The mean and smoothed values are calculated from the estimated daily data, compared with the actual mean, and smoothed values, including standard deviations, and the prediction accuracy of the model is examined. Finally, the number of daily sunspots for ten years into the 25th cycle is estimated, and the results are discussed by calculating the mean and smoothed values. The predicted 25 th solar cycle shows features of a new Dalton minimum along with the 24 th cycle. We think the 25 th solar cycle will be the marker of a new Dalton minimum period.

*This study was performed with a grant under the TUBITAK 117F336 project.

Please cite as: Coban, G.C., Raheem, Au., Cavus, H. et al. Can Solar Cycle 25 Be a New Dalton Minimum?. Sol Phys 296, 156 (2021). https://doi.org/10.1007/s11207-021-01906-1