2025/04/17 by Zhenghua Huang, Zuo, Xiuhui, Huang, Zhenghua +18 · 2 citations
Physics and Astronomy · #Dust and Plasma Wave Phenomena #FOS: Physical sciences #Ionosphere and magnetosphere dynamics #Solar and Space Plasma Dynamics #Solar and Stellar Astrophysics (astro-ph.SR)
paper · pdf · doi:10.48550/arxiv.2504.13009
openalex publication_date 2025/04/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Nanoflares, which are consequences of braids in tangled magnetic fields, are an important candidate to heat the solar corona to million degrees. However, their observational evidence is sparse and many of their observational characteristics are yet to be discovered. With the high-resolution observations taken by the Extreme Ultraviolet Imager onboard the Solar Orbiter, here we study a series of ejections of plasma blobs resulted from a braided magnetic loops in the upper transition region and reveal some critical characteristics of such processes. The cores of these ejections have a size of about 700 km, a duration less than 1 minute and a speed of about 90 \kms. An important characteristic is that these plasma blobs are apparently constrained by the post-reconnection magnetic loops, along which they show an extension of up to about 2 000 km. The propagation of unbraiding nodes along the main axis of the tangled loops has a speed of about 45 \kms. The separation angles between the post-reconnection loops and the main axis of the tangled loops are about 30°. The observations from the Atmospheric Imaging Assembly reveal that the braiding loops are upper transition region structures. Based on these observations, the typical magnetic free energy producing a blob is estimated to be about 3.4×1023 erg, well in the nano-flare regime, while the kinematic energy of a blob is about 2.3×1023 erg, suggesting that a majority of magnetic free energy in a magnetic braid is likely transferred into kinematic energy.