Abstract

Contributed Talk - Splinter Solar

Tuesday, 10 September 2024, 15:40   (S15)

Observation of multi-phase small-scale magnetic field amplification in a vortical structure in the lower solar atmosphere.

Diaz-Castillo, Saida 1,2 ; Fischer, Catherine 3,7; Rezaei, Reza 4; Steiner, Oskar 1,5; Berdyugina, Svetlana 5,6
1.Institute for Solar Physics (KIS), 2.Faculty of Physics, University of Freiburg, 3. National Solar Observatory (NSO), USA 4. Departments of Physics, Sharif University of Technology, Iran 5. Istituto Ricerche Solari Aldo e Cele Daccò (IRSOL), Switzerland, 6. Faculty of Informatics, Università della Svizzera italiana, Switzerland 7. European Space Agency (ESA), European Space Astronomy Centre (ESAC), Spain

High-resolution solar observations revealed the existence of small-scale vortices in the solar atmosphere. These vortices have been observed near magnetic flux concentrations, indicating a link between swirls and the evolution of the small-scale magnetic fields. Vortices were mainly studied with MHD numerical simulations of the solar atmosphere, revealing their complexity and dynamics, and their importance in understanding the interaction of magnetic fields with turbulent convective flows. We present a complete and comprehensive description of the time evolution of a small-scale magnetic flux concentration interacting with the intergranular vortex flow, and affected by processes of intensification and weakening of its magnetic field. We study observations taken with the spectropolarimeter CRISP and Imaging spectrometer CHROMIS at the Swedish Solar Telescope (SST). The data were recorded at the quiet-Sun disk centre, consisting of full Stokes maps in the Fe I line at 617.3nm, in the Ca II line at 854.2nm, and spectroscopic maps in the lines of Hα and Ca II K lines. Performing height-dependent Stokes inversion, methods of local correlation tracking, and wavelet analysis, we can study several atmospheric properties during the event lifetime. We identify the convective collapse process as the initial mechanism of magnetic field intensification, generating a re-bound upflow within the magnetic flux concentration. This disturbance steepens into an acoustic shock wave that dissipates in the lower chromosphere, heating it locally. We observe also prolonged magnetic field amplification happening when the vortex flow disappears. We suggest that such magnetic field amplification can be due to changes in the local vorticity.