2001/08/17 by M. Rieutord, Th. Roudier, T. Roudier +6 · 5 citations
Engineering · Physics and Astronomy · #Fluid Dynamics and Turbulent Flows #Solar and Space Plasma Dynamics #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1051/0004-6361:20011160
4 pages - accepted in Astronomy and Astrophysics
arxiv created 2001/08/17 · openalex publication_date 2001/10/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
Using a numerical simulation of compressible convection with radiative transfer mimicking the solar photosphere, we compare the velocity field derived from granule motions to the actual velocity field of the plasma. We thus test the idea that granules may be used to trace large-scale velocity fields at the sun's surface. Our results show that this is indeed the case provided the scale separation is sufficient. We thus estimate that neither velocity fields at scales less than 2500 km nor time evolution at scales shorter than 0.5 hr can be faithfully described by granules. At larger scales the granular motions correlate linearly with the underlying fluid motions with a slope of ≲2 reaching correlation coefficients up to ~0.9.