| Abstract : | A striking feature of the solar cycle is that at the beginning, sunspots appear around mid-latitudes, and over time the latitudes of emergences migrate towards the equator. The maximum level of activity (e.g., sunspot number) varies from cycle to cycle. For strong cycles, the activity begins early and at higher latitudes with wider sunspot distributions than for weak cycles. The activity and the width of sunspot belts increase rapidly and begin to decline when the belts are still at high latitudes. Surprisingly, it has been reported that in the late stages of the cycle the level of activity (sunspot number), as well as the widths and centers of the butterfly wings all, have the same statistical properties independent of how strong the cycle was during its rise and maximum phases. We have modeled these features using a Babcock–Leighton type dynamo model and shown that the toroidal flux loss from the solar interior due to magnetic buoyancy is an essential nonlinearity in the solar dynamo which leads to all the cycles having similar amount of toroidal flux during their decline phases. Hence all the cycles decline in the same way.
Accepted in Phys. Rev. Lett. (PRL) : https://journals.aps.org/prl/accepted/03074Y69Df61fe7649d843c2868b6a8a24b428c08
For reference please see: https://arxiv.org/abs/2210.07061 |
