Semiempirical Modeling of Large-Scale Flow on the Sun

A horizontal velocity field is used to describe the large-scale transport of magnetic flux over the whole solar photosphere. The image of the 2-D large-scale flow on the sphere is derived from the trajectories of the independent free testing particles driven by the derived velocity field. The horizontal flow displays a velocity gradient and an eddy structure. The horizontal divergence of the vector field is used to describe the cellular-like patterns and limits of the discrete large-scale flow structures. The slow- and long-lived temporal evolution of the flow structures is described.