Göttingen 2025 – wissenschaftliches Programm
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EP: Fachverband Extraterrestrische Physik
EP 4: Sun and Heliosphere II
EP 4.7: Vortrag
Dienstag, 1. April 2025, 15:30–15:45, ZHG101
Probing chromospheric fine structures with an Hα proxy using MURaM — •Sanghita Chandra1, Robert Cameron1, Damien Przybylski1, Sami Solanki1, Patrick Ondratschek1, and Sanja Danilovic2 — 1Max Planck Institute for Solar System Research, Justus von Liebig Weg, 37077 Göttingen, Germany — 2Institute for Solar Physics, Dept. of Astronomy, Stockholm University, Albanova University Center, 10691 Stockholm, Sweden
The solar chromosphere is composed of dynamic fine structures that remain poorly understood. Using the MURaM-ChE code, which incorporates NLTE physics for chromospheric modeling, we simulate an enhanced network element. The results reveal finely structured features resembling rapid red and blue-shifted excursions (RREs and RBEs) in the Hα wings and dynamic fibrils in the line core. We devise a proxy for the Hα spectral line that identifies similar features rooted in network patches, that may play a critical role in supplying mass and energy to the solar corona. One such feature, an RBE with a Doppler shift of 37 km/s, forms through flux emergence and reconnection events, with Lorentz forces expanding the field and driving a jet-like flow. This feature originates in the mid chromosphere (2-4 Mm above the surface), has a lifetime of 246 seconds, reaches 3.4 Mm in length, and exhibits lateral motion. Strong viscous and resistive heating at its onset propagates a heating front at Alfvenic speeds.
Keywords: Sun: chromosphere; Sun: magnetic fields; magnetohydrodynamics; magnetic reconnection