Solar active region scaling laws revisited

TL;DR

This paper revisits and refines the scaling laws of solar active regions based on a comprehensive database, providing improved models for space climate research and active region analysis.

Contribution

It introduces new scaling laws for active region properties using the ARISE database, enhancing the understanding of their magnetic flux relationships and deviations.

Findings

Established new scaling relations for AR area, pole separation, and tilt angle against magnetic flux and latitude.

Modeled residuals from the scaling relations to account for deviations.

Recommended these relations for future space climate modeling and active region identification.

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 $\gamma$ we find scalings against magnetic flux $\Phi$ and heliographic latitude $\lambda$. 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.