Validation of the PDFI_SS method for electric field inversions using a magnetic flux emergence simulation

TL;DR

This paper validates the PDFI_SS method for electric field inversion in solar physics by comparing reconstructed fields with MHD simulation data of magnetic flux emergence, highlighting its accuracy during flux emergence and limitations during shearing phases.

Contribution

The study extends validation of the PDFI_SS method to realistic flux emergence simulations, incorporating spherical geometry and complex evolution phases.

Findings

Good accuracy during flux emergence phase

Decreased accuracy during shearing phase

Complex evolution affects inversion accuracy

Abstract

Knowledge of electric fields in the photosphere is required to calculate the electromagnetic energy flux through the photosphere and set up boundary conditions for data-driven magnetohydrodynamic (MHD) simulations of solar eruptions. Recently, the PDFI_SS method for inversions of electric fields from a sequence of vector magnetograms and Doppler velocity measurements was improved to incorporate spherical geometry and a staggered-grid description of variables. The method was previously validated using synthetic data from anelastic MHD (ANMHD) simulations. In this paper, we further validate the PDFI_SS method, using approximately one-hour long MHD simulation data of magnetic flux emergence from the upper convection zone into the solar atmosphere. We reconstruct photospheric electric fields and calculate the Poynting flux, and compare those to the actual values from the simulations. We find that the accuracy of the PDFI_SS reconstruction is quite good during the emergence phase of the simulated ephemeral active region evolution and decreases during the shearing phase. Analysing our results, we conclude that the more complex nature of the evolution (compared to the previously studied ANMHD case) that includes the shearing evolution phase is responsible for the obtained accuracy decrease.