Constraining non-linear dynamo models using quasi-biennial oscillations from sunspot area data

Results. The results from the sunspot areas show that the QBOs are present in the full disk and hemispheric sunspot areas. These QBOs show slightly different spatial and temporal behaviours, indicating slightly decoupled solar hemispheres.

The QBO signal is generally intermittent and in-phase with the sunspot area data, surfacing when the solar activity is at its maximum. The results from the BLdynamos show that they are neither capable of generating the slightly decoupled behaviour of solar hemispheres nor can they generate QBO-like signals. The turbulent α-dynamos on the other hand generated decoupled hemispheres and some QBO-like shorter cycles.

In conclusion, our simulations show that the turbulent α-dynamos with the Lorentz force seem more efficient in generating the observed temporal and spatial behaviour of the QBO signal compared with the BL-dynamos.