Stellar convection simulations

What are supergranules? Why do they stand out? Preliminary results from realistic simulations of solar convection on supergranule scales (96 Mm wide by 20 Mm deep) are presented. The solar surface velocity amplitude is a decreasing power law from the scale of granules up to giant cells with a slight enhancement at supergranule scales. The simulations show that the size of the horizontal convective cells increases gradually and continuously with increasing depth. Without magnetic fields present there is (as yet) no enhancement at supergranule scales at the surface. A hypothesis is presented that it is the balance between the rate of magnetic flux emergence and the horizontal sweeping of magnetic flux by convective motions that determines the size of the magnetic network and produces the extra power at supergranulation scales.

• Type: Journal
• Year: 2008
• Where: SCHOLARPEDIA
• Authors: Sacha Brun, Mark Miesch
• Keywords: Horizontal Convective Cells, Magnetic Flux, SCHOLARPEDIA 2008, Supergranule Scales