How Reconnection-Unfavored Magnetic Flux Emergence Suppresses Solar Filament Eruptions

TL;DR

This study presents observational evidence that magnetic flux emergence can suppress solar filament eruptions by stabilizing the filament through magnetic reconnection, challenging the traditional view of flux emergence solely as a trigger.

Contribution

It provides the first direct observational evidence that flux emergence can suppress filament eruptions by magnetic reconnection, revealing a dual role in solar activity.

Findings

Flux emergence interacted with filament magnetic field causing reconnection.

Reconnection led to filament stabilization and structural break into segments.

Flux emergence reduced upward net force, suppressing eruption.

Abstract

Magnetic flux emergence is traditionally considered a key trigger of solar filament eruptions; however, its role in suppressing filament eruptions remains less understood. Using multi-wavelength observations from the Solar Dynamics Observatory, this study investigates a unique case of flux emergence below a quiescent filament from January 3 to 5, 2016, where the newly emerging magnetic flux suppressed rather than promoted the eruption of the filament. It is found that the emerging magnetic bipole within the filament channel directly interacted and reconnected with the overlying filament magnetic field and produced a series of two-sided coronal jets along the filament axis. Instead of eruption, the filament kept stable but broke into two segments at the reconnection site. Further magnetic cancellation or recession of the emerged bipole allowed the filament to recover its original structure. Our analysis results revealed that the flux emergence suppressed the filament eruption by reducing the upward net force. The formation and evolution of filament fine structures, such as filament threads, are closely linked to the reconnection processes between the emerging bipole and the horizontal magnetic field of the filament. This study provides direct observational evidence for the stabilization of solar filaments driven by flux emergence, offering new insights into the dual role of magnetic emergence in triggering and suppressing solar eruptions.