Gong Jiancun

The prediction of maximum amplitude ofsolar cycle 25

In this paper, the correlation between various parameters of solar cycles 0-23 is investigated. The parameters include maximum, rising time and descending time. Three derived regression equations are given between maximum and rising time. Two derived regression equations are given between descending time and total of descending time and next rising time. Additionally, according to the cycle periodicity of secular trend and the regularity of maximum between even cycles and following odd cycles, the prediction of cycle 25 is obtained. It is expected that solar cycle 25 will begin in June 2020 and will be relatively stronger than cycle 24. The sunspot number maximum of cycle 25 is predicted to occur in April 2024 with a sunspot number of 119.2±5.5, which will be nearly the same strength of cycle 17 and 23.