Can we Determine Electric Fields and Poynting Fluxes from Vector Magnetograms and Doppler Measurements?

TL;DR

This paper presents a method to accurately estimate the electric field and Poynting flux in the solar photosphere by combining vector magnetogram data with Doppler flow measurements, improving understanding of magnetic energy buildup.

Contribution

It introduces a technique that integrates Doppler and transverse flow data with PTD magnetic field solutions to better determine electric fields and energy fluxes in the solar photosphere.

Findings

Enhanced accuracy in electric field estimation using combined data.

Improved Poynting flux maps for studying solar magnetic energy buildup.

Potential for better prediction of solar flares and eruptions.

Abstract

The availability of vector magnetogram sequences with sufficient accuracy and cadence to estimate the time derivative of the magnetic field allows us to use Faraday's law to find an approximate solution for the electric field in the photosphere, using a Poloidal-Toroidal Decomposition (PTD) of the magnetic field and its partial time derivative. Without additional information, however, the electric field found from this technique is under-determined -- Faraday's law provides no information about the electric field that can be derived the gradient of a scalar potential. Here, we show how additional information in the form of line-of-sight Doppler flow measurements, and motions transverse to the line-of-sight determined with ad-hoc methods such as local correlation tracking, can be combined with the PTD solutions to provide much more accurate solutions for the solar electric field, and therefore the Poynting flux of electromagnetic energy in the solar photosphere. Reliable, accurate maps of the Poynting flux are essential for quantitative studies of the buildup of magnetic energy before flares and coronal mass ejections.