There has been a debate on the topic "Why the sunspot number needs re-examination?". What is the reason behind this controversial topic? Which model is currently the best model to predict the Sunspot Number in Solar Cycle 25?
Solar Dynamo: The Solar cycle provides significant constraints to all dynamo Models.
Space Weather--Space Hazards: The understanding of Solar is a significant factor (though not the only one) affecting prediction of Space Weather and assessment of Space Hazards. Furthermore, the Space Weather is thought to affect Climate although the interconnection is somewhat unclear.
A rather controversial about of the relationship of sunspots to earthquakes is been studied in a number of papers...