Photospheric Electric Fields and Energy Fluxes in the Eruptive Active Region NOAA 11158

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Introduction

The advent of high-cadence vector magnetic field and Doppler velocity measurements from e.g. HMI/SDO, SOT/Hinode and SOLIS, have made the estimation of electric fields in the solar photosphere possible. The calculation of the electric field from magnetic and Doppler data is critically important for various quantitative studies of the solar atmosphere. First, if we know both electric and magnetic field vectors in the photosphere, we can estimate both the Poynting flux of magnetic energy and the flux of relative magnetic helicity entering the corona. Second, knowledge of electric and magnetic fields enables the driving of time-dependent simulations of the coronal magnetic field. This is the goal of the Coronal Global Evolutionary Model (CGEM, Fisher et al. 2015).

Method

We have recently improved the electric field inversion methods introduced by Fisher et al. (2010), to create a comprehensive technique for calculating photospheric electric fields from vector magnetogram sequences (Kazachenko et al. 2014). The new method, which we dubbed the PDFI (an abbreviation for PTD-Doppler-FLCT-Ideal technique, where PTD is Poloidal-toroidal Decomposition and FLCT is Fourier Local Correlation Tracking), has been systematically tested for accuracy and robustness, using synthetic data from ANMHD simulations. Here we take the next step forward, and apply the PDFI technique to observations.