Theory 76/Solar cycle/Onset phase
Cycle Starts on a Flux Threshold
The claim
A solar cycle begins when the ratio of toroidal to poloidal field strength exceeds a threshold, so the timing depends on the field configuration rather than on time.
01Mechanism
The dynamo converts one field component into the other; the ratio sets the onset.
02Prediction
Onset should track the field ratio.
03Refutation
Onset tracking a fixed period would remove the dynamo.