2001/11/29 by P. J. Käpylä, P. J. Kapyla, Kapyla, P. J. +2
Earth and Planetary Sciences · Physics and Astronomy · #Astrophysics (astro-ph) #Astrophysics and Star Formation Studies #FOS: Physical sciences #High-pressure geophysics and materials #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0111554
4 pages, 3 postscript figures, submitted to A&A Letters
arxiv created 2001/11/29 · openalex publication_date 2001/11/29 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this letter, we present numerical calculations made to investigate the possible resolution dependence of the Shakura & Sunyaev (1973) viscosity parameter alpha from local magnetohydrodynamic simulations of the magnetorotational instability (MRI). We find that the values of alpha do indeed depend significantly on the numerical resolution but also that when the highest resolutions attainable by the computational resources available are used, the growth of the alpha-parameter seems to saturate. The values of alpha are at most of the order of 10^(-3), which indicates that the sole presence of turbulence due to dynamo generated magnetic field in the disk is not enough to reproduce alphas of the order unity which could explain some observational results (e.g. Cannizzo 1993).