The differential rotation of the solar surface

view Abstract Citations (27) References (14) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Differential Rotation of the Solar Surface Gierasch, Peter J. Abstract The large-scale flow in the solar convection zone is discussed. The objective is to deduce from observation the principal physical balances in the governing equations. The simplest set of equations that seem potentially realistic are utilized. It is assumed that magnetic fields are negligible, that mixing-length theory gives an accurate representation of the mean structure, and that rigid-body rotation exists at the base. It is deduced that the zonal flow is geostrophic, the meridional flow is controlled by friction, and diffusive heating balances advective cooling due to vertical motion. Next, a detailed calculation of the latitude profile of surface angular velocity is performed, based on approximate equations containing only the principal balances, and agrees well with observation. Finally, it is demonstrated that the amplitude of the flow may be determined by the constraint that the net equatorward angular momentum flux vanish. The conclusions are consistent with the hypothesis that the flow is primarily a single large axisymmetric convection cell in each hemisphere. There is contradiction with the observation of no equator-pole flux variation, but this may be due to oversimplification of equations and boundary conditions. Subject headings: convection - interiors, solar - rotation, solar Publication: The Astrophysical Journal Pub Date: May 1974 DOI: 10.1086/152864 Bibcode: 1974ApJ...190..199G full text sources ADS |