Solar Flare Prediction Using Magnetic Field Diagnostics Above the Photosphere

TL;DR

This study applies the WGM magnetic field diagnostic to 3D solar magnetic structures to identify an optimal height range above the photosphere for earlier flare prediction, improving timing by several hours.

Contribution

It introduces a method to determine the best height above the photosphere for flare prediction using 3D magnetic field extrapolations and the WGM technique.

Findings

Optimal prediction height is between 1000 and 1800 km above the surface.

Flare onset time can be predicted 2-8 hours earlier at this height.

Applying WGM at this height enhances early warning capabilities.

Abstract

In this article, we present the application of the weighted horizontal gradient of magnetic field (WGM) flare prediction method to 3-dimensional (3D) extrapolated magnetic configurations of 13 flaring solar active regions (ARs). The main aim is to identify an optimal height range, if any, in the interface region between the photosphere and lower corona, where the flare onset time prediction capability of WGM is best exploited. The optimal height is where flare prediction, by means of the WGM method, is achieved earlier than at the photospheric level. 3D magnetic structures, based on potential and non-linear force-free field extrapolations, are constructed to study a vertical range from the photosphere up to the low corona with a 45 km step size. The WGM method is applied as a function of height to all 13 flaring AR cases that are subject to certain selection criteria. We found that applying the WGM method between 1000 and 1800 km above the solar surface would improve the prediction of the flare onset time by around 2-8 hours.Certain caveats and an outlook for future work along these lines are also discussed.