Microflare Activity driven by Forced Magnetic Reconnection

TL;DR

This study presents high-resolution solar observations showing microflare activity driven by forced magnetic reconnection, evidenced by velocity perturbations and Ellerman bombs near magnetic neutral lines.

Contribution

First observational evidence linking forced magnetic reconnection to microflare activity in the solar atmosphere.

Findings

Velocity perturbations of +/- 6 km/s near neutral lines.

Detection of Ellerman bombs associated with magnetic reconnection.

Reconnection occurs approximately 200 km above the solar surface.

Abstract

High cadence, multiwavelength, optical observations of a solar active region are presented, obtained with the Swedish Solar Telescope. Two magnetic bright points are seen to separate in opposite directions at a constant velocity of 2.8km/s. After a separation distance of approximately 4400km is reached, multiple Ellerman bombs are observed in both H-alpha and Ca-K images. As a result of the Ellerman bombs, periodic velocity perturbations in the vicinity of the magnetic neutral line, derived from simultaneous MDI data, are generated with amplitude +/- 6km/s and wavelength 1000km. The velocity oscillations are followed by an impulsive brightening visible in H-alpha and Ca-K, with a peak intensity enhancement of 63%. We interpret these velocity perturbations as the magnetic field deformation necessary to trigger forced reconnection. A time delay of approximately 3min between the H-alpha wing and Ca-K observations indicate that the observed magnetic reconnection occurs at a height of 200km above the solar surface. These observations are consistent with theoretical predictions and provide the first observational evidence of microflare activity driven by forced magnetic reconnection.