Solar active region scaling laws revisited

Abstract

The systematic variation of solar active region (AR) properties with their magnetic flux has been the subject of numerous studies but the proposed scaling laws still vary rather widely. A correct representation of these laws and the deviations from them is important for modelling the source term in surface flux transport and dynamo models of space climate variation, and it may also help constrain the subsurface origin of active regions. Here we determine active region scaling laws based on the recently constructed ARISE active region data base listing bipolar ARs for cycle 23, 24 and 25. For the area $A$, pole separation $d$ and tilt angle $γ$ we find scalings against magnetic flux $Φ$ and heliographic latitude $λ$. Residuals from these relations are also modelled. These scaling relations are recommended for use in space climate research for the modelling of future data or missing past data, as well as for the identification of candidate rogue ARs.