A method for constructing streamlines for the Sun's large scale flow from Doppler velocities

We show that, if the large scale departures from the mean differential rotation, measured by Howard and Harvey, represent nearly horizontal flow, we may under certain assumptions deduce a pattern of streamlines for these motions from the doppler line of sight velocities. This can be done with data from a single day, without having to construct the total flow from different projections of the (assumed) same velocity vectors seen on different days. Mathematically the method involves integrating a single first order inhomogeneous partial differential equation along a set of characteristic curves which are circles concentric with the center of the solar disk. The structure of the resulting streamline pattern could be compared to large scale magnetic patterns, and latitudinal transports of magnetic flux and momentum could be estimated.