2013/12/03 by I. N. Kitiashvili, Irina Kitiashvili, А. Г. Косовичев +8 · 1 citation
Biochemistry, Genetics and Molecular Biology · Physics and Astronomy · #Astro and Planetary Science #Astrophysics #Convection #Convection zone #Dynamo #Dynamo theory #Earth's magnetic field #FOS: Physical sciences #Geomagnetism and Paleomagnetism Studies #Geophysics #L-shell #Magnetic field #Magnetohydrodynamics #Mechanics #Mercury's magnetic field #Optics #Photosphere #Physics #Radiative transfer #Solar and Space Plasma Dynamics #Solar and Stellar Astrophysics (astro-ph.SR) #Solar dynamo #astro-ph.SR
paper · pdf · doi:10.48550/arxiv.1312.0982
21 pages, 11 figures, submitted to ApJ
arxiv created 2013/12/03 · openalex publication_date 2013/12/03 · arxiv updated 2013/12/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
In the quiet Sun, magnetic fields are usually observed as small-scale magnetic elements, `salt and pepper', covering the entire solar surface. By using 3D radiative MHD numerical simulations we demonstrate that these fields are a result of local dynamo action in the top layers of the convection zone, where extremely weak `seed' magnetic fields can locally grow above the mean equipartition field (e.g., from a 10-6 G `seed' field to more than 1000 G magnetic structures). We find that the local dynamo action takes place only in a shallow, about 500 km deep, subsurface layer, from which the generated field is transported into deeper layers by convection downdrafts. We demonstrate that the observed dominance of vertical magnetic fields at the photosphere and the horizontal fields above the photosphere can be explained by multi-scale magnetic loops produced by the dynamo.