R. C. Ygbuhay

Sunspot Cycle 24 and the Advent of Dalton-Like Minimum

Ahluwalia and Jackiewicz (2011) have predicted that sunspot cycle 24 will be only half as active as cycle 23, reaching its peak in May 2013±6 months. Here, we discuss the timeline for cycle 24 since its onset in December, 2008 and compare it to the timelines for the last ten cycles (14 to 23) of the 20th century; cycle 24 is rising the slowest. We speculate that cycle 24 may herald the onset of a Dalton-like minimum in the 21st century. The implications of this outcome on global temperature change and ensuing socioeconomic and political scenarios are discussed, on the basis of the historical record.

Current Forecast for Sunspot Cycle 24 Parameters

Our prediction for the development of sunspot cycle 23 activity came true; one of the very few to have attained this status. We use the 3‐cycle quasi‐periodicity observed in the planetary index Ap. We improve our method by including data for 150 years and draw inferences as to what to expect for the development phase of cycle 24. Our forecast for the smoothed sunspot number at cycle 24 peak 78±5 in June 2013; the possibility that next three cycles may be progressively less active cannot be ruled out; the trend may possibly continue for the rest of the 21st century.