2007/07/10 by Mark S. Miesch, Allan Sacha Brun, A. S. Brun +3 · 5 citations
Biochemistry, Genetics and Molecular Biology · Physics and Astronomy · #Astronomy #Astrophysics #Combined forced and natural convection #Convection #Convection cell #Convection zone #Differential rotation #Geology #Geomagnetism and Paleomagnetism Studies #Geometry #Geophysics #Helioseismology #Mechanics #Natural convection #Photosphere #Physics #Rotation (mathematics) #Solar and Space Plasma Dynamics #Stars #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/523838
22 pages, 16 figures (color figures are low res), uses emulateapj.cls Latex class file, Results shown during a Press release at the AAS meeting in June 2007. Submitted to ApJ
arxiv created 2007/07/10 · openalex publication_date 2008/01/16 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The global scales of solar convection are studied through three-dimensional simulations of compressible convection carried out in spherical shells of rotating fluid that extend from the base of the convection zone to within 15 Mm of the photosphere. Such modeling at the highest spatial resolution to date allows study of distinctly turbulent convection, revealing that coherent downflow structures associated with giant cells continue to play a significant role in maintaining the differential rotation that is achieved. These giant cells at lower latitudes exhibit prograde propagation relative to the mean zonal flow, or differential rotation, that they establish, and retrograde propagation of more isotropic structures with vortical character at mid and high latitudes. The interstices of the downflow networks often possess strong and compact cyclonic flows. The evolving giant-cell downflow systems can be partly masked by the intense smaller scales of convection driven closer to the surface, yet they are likely to be detectable with the helioseismic probing that is now becoming available. Indeed, the meandering streams and varying cellular subsurface flows revealed by helioseismology must be sampling contributions from the giant cells, yet it is difficult to separate out these signals from those attributed to the faster horizontal flows of supergranulation. To aid in such detection, we use our simulations to describe how the properties of giant cells may be expected to vary with depth and how their patterns evolve in time.