Sub-surface Plasma Flows and the Flare Productivity of Solar Active Regions

TL;DR

This study links subsurface plasma flow characteristics, such as vorticity and helicity, to the flare productivity of solar active regions, suggesting these parameters can predict flare intensity.

Contribution

It demonstrates that subsurface flow parameters like vorticity and helicity are significantly correlated with flare activity, providing potential predictive indicators.

Findings

Large vorticity and helicity are associated with flaring regions.

Flow and magnetic parameters evolve in phase and correlate with flare intensity.

Pre-flare flow parameters can predict the magnitude of solar flares.

Abstract

The extreme space weather conditions resulting from high energetic events likes solar flares and Coronal Mass Ejections (CMEs) demand for reliable space weather forecasting. The magnetic flux tubes while rising through the convection zone gets twisted by the turbulent plasma flows, energizing the system and resulting in flares. We investigate the relationship between the subsurface plasma flows associated with flaring active regions and their surface magnetic flux and current helicity. The near-surface horizontal velocities derived from the ring-diagram analysis of active region patches using Global Oscillation Network Group (GONG) Doppler velocity measurements are used to compute the fluid dynamics descriptors like vertical divergence, vorticity and kinetic helicity used in this work. The flaring active regions are observed to have large value of vertical vorticity and kinetic helicity. Also, the horizontal flow divergence, vorticity, flux, kinetic and current helicities are observed to be significantly correlated and evolve in phase with each other. We observe that the integrated values of the above flow and magnetic parameters observed one day prior to the flare are significantly correlated with the integrated flare intensity of the active region. Hence, we show that strong vorticity/kinetic helicities lead to larger active region twisting, presumably generating high-intensity flares.