Abstract Details


Name: Dr. Lisa Upton
Affiliation: Southwest Reseach Institute
Conference ID: TVS202510250
Title: Quantification of the Rate of Active Region Emergence on the Sun
Authors and Co-Authors: Bibhuti K. Jha
Abstract Type: Invited by SOC
Abstract: The official International sunspot number (SSN) is produced and preserved by the Sunspot Index and Long-term Solar Observations (SILSO) group at the Royal Observatory of Belgium. The SSN is an historical index that is widely accepted as the metric for quantifying solar cycle activity on the Sun by counting the number of sunspot groups and the number of individual sunspots on the Earth-facing side of the Sun each day. These two numbers are added and then multiplied by a scaling factor that accounts for differences from observer to observer. Due to the nature of how it is created the SSN is a metric that quantifies the number of active regions (ARs) on one hemisphere of the Sun on a given day. A more useful metric for the purpose of simulating AR emergence and evolution in a model would be the rate of AR emergence. Here we present our efforts quantifying the rate of AR emergence as a function of the SSN. This is an essential component of our newly developed Synthetic Active Region Generator (SARG), a tool for generating synthetic AR catalogs as source terms for surface flux transport models such as the Advective Flux Transport (AFT) model. SARG relies solely on artificial sunspot cycle profiles, or the SSN itself, to generate a series of ARs with observed statistical properties (e.g., flux, location, and timing). SARG can be used to create many realizations that can be incorporated into the model to investigate the uncertainty due to the stochastic nature of AR emergence observed on the Sun. Here, we present the quantification of the AR emergence rate and describe SARG. We also show a use case scenario where SARG was used with AFT to predict the evolution of the polar magnetic fields during Solar Cycle 25.