Software has been developed to identify and track supergranulation cells. Initial results show that half the cells are lost in 20 hours. We are currently construct- ing high resolution data sets of 90 hours duration and will shortly have an initial estimate of the mechanisms for the evolution of supergranulation. Analysis of full disk data using time distance methods has shown that differential rotation differs in the north and south hemispheres, confirming inferences from magnetic field pattern rotation. Comparison with the surface flows directly observed in the Doppler signal shows nearly identical flow patterns.
Observations are currently underway.
Magnetic Evolution Magnetic Fields Determine how the quiet and active magnetic fields evolve in time and space. The large scale pattern of magnetic fields over the solar surface is well explained by a model that takes as its source emerging active regions and as its distribution mechanism diffusion and meridional flow. The mechanism for diffusion is thought to be supergranulation evolu- tion. In quiet Sun magnetic fields are observed everywhere. This field is due to local emergences that may not contribute to large scale field evolution, but do play a major role in heating of the outer atmosphere and generation of the solar wind.